339 results on '"Van Wyk, Abraham E."'
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2. Temperature controls phenology in continuously flowering Protea species of subtropical Africa.
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Daru, Barnabas H, Kling, Matthew M, Meineke, Emily K, and van Wyk, Abraham E
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Cape Floristic Region ,Protea ,day of flowering year ,flowering phenology ,global warming ,herbarium specimens ,Crop and Pasture Production - Abstract
Premise of the Study:Herbarium specimens are increasingly used as records of plant flowering phenology. However, most herbarium-based studies on plant phenology focus on taxa from temperate regions. Here, we explore flowering phenologic responses to climate in the subtropical plant genus Protea (Proteaceae), an iconic group of plants that flower year-round and are endemic to subtropical Africa. Methods:We present a novel, circular sliding window approach to investigate phenological patterns developed for species with year-round flowering. We employ our method to evaluate the extent to which site-to-site and year-to-year variation in temperature and precipitation affect flowering dates using a database of 1727 herbarium records of 25 Protea species. We also explore phylogenetic conservatism in flowering phenology. Results:We show that herbarium data combined with our sliding window approach successfully captured independently reported flowering phenology patterns (r = 0.93). Both warmer sites and warmer years were associated with earlier flowering of 3-5 days/°C, whereas precipitation variation had no significant effect on flowering phenology. Although species vary widely in phenological responsiveness, responses are phylogenetically conserved, with closely related species tending to shift flowering similarly with increasing temperature. Discussion:Our results point to climate-responsive phenology for this important plant genus and indicate that the subtropical, aseasonally flowering genus Protea has temperature-driven flowering responses that are remarkably similar to those of better-studied northern temperate plant species, suggesting a generality across biomes that has not been described elsewhere.
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- 2019
3. Figure 4 from: van Wyk AE, Boon RG (2024) Marijordaania (Celastraceae: Cassinoideae), a new monotypic genus from South Africa. Plant Ecology and Evolution 157(1): 100-112. https://doi.org/10.5091/plecevo.116544
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van Wyk, Abraham E., primary and Boon, Richard G.C., additional
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- 2024
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4. Figure 3 from: van Wyk AE, Boon RG (2024) Marijordaania (Celastraceae: Cassinoideae), a new monotypic genus from South Africa. Plant Ecology and Evolution 157(1): 100-112. https://doi.org/10.5091/plecevo.116544
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van Wyk, Abraham E., primary and Boon, Richard G.C., additional
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- 2024
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5. Figure 1 from: van Wyk AE, Boon RG (2024) Marijordaania (Celastraceae: Cassinoideae), a new monotypic genus from South Africa. Plant Ecology and Evolution 157(1): 100-112. https://doi.org/10.5091/plecevo.116544
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van Wyk, Abraham E., primary and Boon, Richard G.C., additional
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- 2024
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6. Figure 2 from: van Wyk AE, Boon RG (2024) Marijordaania (Celastraceae: Cassinoideae), a new monotypic genus from South Africa. Plant Ecology and Evolution 157(1): 100-112. https://doi.org/10.5091/plecevo.116544
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van Wyk, Abraham E., primary and Boon, Richard G.C., additional
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- 2024
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7. Petalidium etendekaense (Acanthaceae), a new species from Namibia, with notes on the taxonomic identity of P. glutinosum
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SWANEPOEL, WESSEL, primary, MANZITTO-TRIPP, ERIN A., additional, DEXTER, KYLE G., additional, and VAN WYK, ABRAHAM E., additional
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- 2024
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8. Cyphia deliae (Campanulaceae: Cyphioideae), a new species from South Africa and Eswatini
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STEYN, HESTER M., primary and VAN WYK, ABRAHAM E., additional
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- 2024
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9. A new species of Sesamothamnus (Pedaliaceae) from Namibia and Angola
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SWANEPOEL, WESSEL, primary and VAN WYK, ABRAHAM E., additional
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- 2023
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10. A New Species of Pavetta (Rubiaceae) from South Africa
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Siebert, Stefan J, Retief, Elizabeth, Van Wyk, Abraham E, and BioStor
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- 2013
11. (2580) Proposal to conserve the name Astroloba against Poellnitzia ( Asphodelaceae : Alooideae )
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Smith, Gideon F., Figueiredo, Estrela, Klopper, Ronell R., and van Wyk, Abraham E.
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- 2018
12. Foliar secretory structures in Ekebergia capensis (Meliaceae)
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Tilney, Patricia M., Nel, Magda, and van Wyk, Abraham E.
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- 2018
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13. Senecio namibensis (Asteraceae: Senecioneae), a new species from Namibia
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Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, and Van Wyk, Abraham E.
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Tracheophyta ,Magnoliopsida ,Asterales ,Biodiversity ,Plant Science ,Asteraceae ,Plantae ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
Senecio namibensis is described as a new species known only from the northern part of the Namib Desert in northwestern Namibia. It is a range-restricted species near-endemic to the Kaokoveld Centre of Endemism. These dwarf shrubs grow on rocky outcrops under harsh desert conditions. Diagnostic characters for Senecio namibensis include the annual or perennial habit, succulent leaves, and radiate capitula with 3–6 yellow ray florets. A comparison of some of the more prominent morphological features to differentiate between S. namibensis and its possible nearest relatives, S. englerianus and S. flavus, is provided. All three species have superficially similar looking succulent leaves, but an obvious difference is that the capitula in S. englerianus are discoid and in S. flavus disciform or obscurely radiate. Based on IUCN Red List categories and criteria, a conservation assessment of Least Concern (LC) is recommended for the new species.
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- 2022
14. A New Species of Gymnosporia (Celastraceae) from Southern Africa
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Jordaan, Marie and van Wyk, Abraham E.
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- 2005
15. A Phytogeographical Classification and Survey of the Indigenous Browse Flora of South Africa, Lesotho, and Eswatini
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Trytsman, Marike, primary, Müller, Francuois L., additional, Samuels, M. Igshaan, additional, Cupido, Clement F., additional, and van Wyk, Abraham E., additional
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- 2023
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16. A New Tribal Classification of Mesembryanthemaceae: Evidence from Floral Nectaries
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Chesselet, Pascale, Smith, Gideon F., and van Wyk, Abraham E.
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- 2002
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17. Preface
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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18. Biocultural Significance and Toxicity
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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19. The Genus Kalanchoe
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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20. Characters, Pollination Biology and Life Cycle
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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21. Taxonomic Treatment
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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22. Physiology and Anatomy
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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23. Geographical Distribution and Ecology
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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24. Crassulaceae of the World
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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25. Crassulaceae in Southern Africa
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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26. Gardening
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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27. Invasiveness
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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28. Kalanchoe in Southern Africa
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Smith, Gideon F., primary, Figueiredo, Estrela, additional, and van Wyk, Abraham E., additional
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- 2019
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29. A new species of Phyllogeiton (Rhamnaceae: Rhamneae) from Maputaland, South Africa
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BOON, RICHARD G.C., primary and VAN WYK, ABRAHAM E., additional
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- 2023
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30. Petalidium konkiepense (Acanthaceae), a new species from Namibia
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SWANEPOEL, WESSEL, primary and VAN WYK, ABRAHAM E., additional
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- 2023
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31. (2469–2472) Proposals to reject the names Aloe perfoliata, A. obscura, A. picta , and A. perfoliata var. saponaria ( A. saponaria ) ( Asphodelaceae : Alooideae )
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Klopper, Ronell R., Smith, Gideon F., Figueiredo, Estrela, and van Wyk, Abraham E.
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- 2016
32. Phyllogeiton trachybasis R. G. C. Boon & A. E. van Wyk 2023, sp. nov
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Boon, Richard G. C. and Van Wyk, Abraham E.
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Tracheophyta ,Magnoliopsida ,Phyllogeiton ,Rhamnaceae ,Phyllogeiton trachybasis ,Biodiversity ,Rosales ,Plantae ,Taxonomy - Abstract
Phyllogeiton trachybasis R.G.C.Boon & A.E.van Wyk, sp. nov. (Figs 1–4) Diagnosis:— Morphologically most similar to Phyllogeiton discolor from which it differs particularly by the following characters: bark on the bole of mature trees almost black, very rough, exfoliating in large pieces; leaves fresh green and without a bloom, ± concolorous, apex acuminate; petals spreading to somewhat ascending at anthesis; fruit oblong-ellipsoid, up to 25 × 19 mm, exocarp often indistinctly longitudinally ribbed, bright orange-yellow; disc-shaped receptacle at point of fruit stalk’s attachment to base of fruit plane. Type:— SOUTH AFRICA. KwaZulu-Natal: Hluhluwe, Bonamanzi Game Park [Reserve], game lodge car park, (2832AA/AB) [2832AB], 5 March 1996, Abbott 6929 (holotype PRU: 081091; isotypes NH, PCE). “ Berchemia sp. nov. ” in Coates Palgrave (2002: 669); Boon (2010: 332); Van Wyk & Van Wyk (2013: 410); Du Randt (2018: 316). “ Berchemia sp. A ” in Schmidt (2018: 546). Illustrations: Boon (2010: 333, Berchemia sp. nov. one photograph in second row from top, two in third row from the top); Van Wyk et al. (2011: 125, Berchemia sp. nov.); Du Randt (2018: 317, Berchemia sp. nov.); Schmidt (2018: 546, Berchemia sp. A). Semi-deciduous, erect tree up to 12(–15) m tall. Trunk single-stemmed and forking below 2.5 m or double-stemmed from near ground level, individual stems up to 0.55 m diam. at breast height (dbh). Bark very rough at the base of old trees, flaking in large pieces, flakes very often persistent, dark, almost black, sometimes with pale grey patches of crustose lichen, bark on upper bole and large branches thick, grey, tessellate, revealing dark bark below where peeling, fissured but fairly smooth on young branches. Heartwood (from dead branch ca. 130 mm in diam.) yellowish brown with a reddish or pinkish tinge towards the sapwood. Branchlets pendent, terete to ± longitudinally ribbed, smooth, lenticellate, initially green, becoming dark brown and then grey, glabrous. Stipules intrapetiolar, base broad, apex acute at first but fugacious, 2–3 mm long, green at first, basal remains becoming dark brown. Leaves opposite, sub-opposite (or occasionally alternate), distichous, simple, ovate to broadly elliptic, (35–)55–100(–115) × (20–)30–40(–50) mm, base rounded, apex broadly acuminate, occasionally acute, very occasionally obtuse, glabrous, firmly chartaceous, glossy, pale green at first, becoming fresh green, slightly paler but without a bloom below and very often with a yellowish tinge, margin entire, undulate, venation craspedodromous, usually slightly impressed above and slightly raised below, yellowish and paler than the lamina, principal lateral veins in (6–)7–9(–10) alternate pairs, tertiary venation minutely reticulate. Petiole canaliculate above, (7–)11–12(–20) mm long, glabrous. Inflorescences axillary (or terminal), flowers solitary or in 2–5(–7)-flowered sub-fascicles. Flowers bisexual, actinomorphic, ca. 8 mm diameter, pedicel ca. 10 mm long, receptacle flattish. Sepals 1-seriate, 5, free, ascending at anthesis, ovate to deltate, keeled on the adaxial surface, 3.0–3.5 × 2.0– 2.5 mm, pale green to yellow-green, glabrous. Petals 1-seriate, 5, free, alternate with sepals, somewhat spreading to ascending at anthesis, narrow and longitudinally folded upwards to clasp the filament, equal in length to sepals or slightly shorter, base unguiculate, apex cucullate, pale green, glabrous. Stamens 5, haplostemonous. Filaments inserted under the disc, ± equal in length to and clasped by the petals, whitish. Anthers basifixed, extrorse, whitish. Ovary superior, 2-locular, largely enveloped by the swollen, pale yellow disc, style apex 2-fid. Fruit a drupe, remains of disc and receptacle prominent at the base, oblong-ellipsoid, often faintly ribbed longitudinally, this being more pronounced in young and dry fruit, 18–25 × 16–19 mm, but often narrower (from ca. 12 mm) in dried material, receptacle at point of fruit stalk’s attachment to base of fruit disc-shaped and plane, exocarp glabrous, green ripening bright orange-yellow, mesocarp fleshy, endocarp woody, stone ellipsoid-ovoid, 15–20 × 10–12 mm. Phenology:— Flowering is mainly in spring from late October to early December at the same time that the new leaves are produced. Fruits are present from November to May and begin ripening in March. Distinguishing characters:— The new species is frequently confused with Phyllogeiton discolor, but the two species’ ranges are allopatric with a gap of ca. 300 km between the closest populations. Phyllogeiton trachybasis is easily distinguished from P. discolor by usually growing on dry, sandy soils (vs. usually adjacent to rivers or on termitaria), bark on the bole of mature trees almost black, very rough, exfoliating in large pieces (vs. grey-brown, rough, tessellated), branchlets and leaves glabrous (vs. glabrous or minutely and densely pubescent; on leaves pubescence mainly on the abaxial surface, but the adaxial surface may also be minutely pubescent about the midrib), leaf blade fresh green, without a bloom, ± concolorous (vs. dark green, distinctly paler with a greyish bloom below), leaf apex acuminate (vs. acute to obtuse), petals spreading to somewhat ascending at anthesis (vs. spreading to reflexed), fruit oblong-ellipsoid (vs. slightly or markedly ovoid), up to 25 × 19 mm (vs. up to 20 × 11 mm), exocarp often indistinctly longitudinally ribbed (vs. plane), bright orange-yellow, even when overripe (vs. yellow but very often pale yellow; often brownish yellow when overripe), and disc-shaped receptacle at point of fruit stalk’s attachment to base of fruit plane (vs. concave). Etymology:— The specific epithet “ trachybasis ” is derived from the Greek τραχυς, trachys, rough or shaggy, and βασις, basis, base or pedestal, referring to the bark towards the base of the trunk in old trees that becomes very thick, rough and flaking in large pieces (Figs 1 & 2A–D). The epithet is used here as a noun in apposition: “the shaggy base” and therefore does not necessarily agree in gender with the genus name. Distribution:— Phyllogeiton trachybasis is only known with certainty from the southern part of the Maputaland Centre of Endemism, an area rich in restricted-range plants and animals (Van Wyk 1996, Van Wyk & Smith 2001). The Maputaland Centre is at the southern end of the tropics in Africa (Van Wyk 1996) and at the northern end of the Maputaland-Pondoland-Albany Hotspot, one of 36 global biodiversity hotspots (Steenkamp et al. 2004). Within the Maputaland Centre, P. trachybasis is known from 10 localities in KwaZulu-Natal (Fig. 5). These localities range from Hluhluwe and Lake St Lucia in the south to Tembe Elephant Park and Ndumo Game Reserve just south of the South African and Mozambican border in the north. There are no specimens of P. trachybasis at the Institute for Agricultural Research of Mozambique herbarium (LMA) and its presence in Mozambique needs confirmation. The species is, however, almost certainly present in the far south of Mozambique’s Maputo Province considering that trees of the new species were found in Tembe Elephant Park on the South African side directly next to the border between the two countries. A sight record (E. Schmidt, pers. comm.) and information supplied by a traditional healer (C. Hanekom, pers. comm.) suggest that it may occur at the Maputo Special Reserve south of Maputo, but confirmation is required. Two other possible localities for the new species should be mentioned. The first is ca. 60 km from Caia in Sofala Province, Mozambique, on the EN1 route to Gorongosa (grid 1834BA), where a sterile specimen (J.E. & S.M. Burrows 8807 in Herb. BNRH) was collected by botanists familiar with the tree. This location is nearly 1000 km north of confirmed localities in KwaZulu-Natal. The second locality is near Siteki in Scarp Forest at an elevation of 450 m in the Lebombo [Lubombo] Mountains of Eswatini (formerly Swaziland), about 40 km north of Ndumo Game Reserve (grid 2631BD). A specimen collected here (P. & L. Loffler s.n. in Herb. BNRH) and photographs supplied by L. Loffler appear to match P. trachybasis, but the five trees seen were all sterile.Another collection from this same locality is also sterile (Schmidt 4054 in Ernst Schmidt Private Herbarium). Given that these specimens lack reproductive material, the presence of the species in Mozambique and Eswatini still needs to be confirmed. Ecology:— Phyllogeiton trachybasis is a sub-canopy or canopy tree found mainly on well-drained, deep sandy soils at low elevations to about 100 m above sea level. Trees grow mainly in Tembe Sandy Bushveld (SVl 18) in open to closed woodland (codes of vegetation types follow Mucina & Rutherford 2006 and SANBI 2006–2018). They also grow in Sand Forest (FOz 8) patches in a mosaic with Tembe Sandy Bushveld (Fig. 1). The species may also occur in Western Maputaland Sandy Bushveld (SVI19) at Ndumo Game Reserve, but information recorded on collecting labels is insufficient to confirm its presence in this vegetation type. Phyllogeiton trachybasis has also been collected between Cape Vidal and Lake Sibaya in dune forest, which is included in the broader category Northern Coastal Forest (FOz 7). The most recent of these collections was in 1997, but the demographics of the species in dune forest are unknown. Besides its normal sandy habitat, the species was collected once (Moll 5291 in Herbs K, NH, PRE) in 1971 from riverine forest embedded in Zululand Lowveld (SVl 23). This was on the Mansiya River in the Hluhluwe-iMfolozi Park where the presence of eight trees growing in the river’s floodplain was recently confirmed (F. du Randt, S. Louw, and S. Mabongwa, pers. comm.). The new species also apparently occurs occasionally in Scarp Forest (FOz 5). It was collected in this forest type in 1959 in the Hluhluwe-iMfolozi Park on a steep, southwest-facing rocky slope at an elevation of about 500 m (Ward 2947 in Herb. NU). A visit by F. du Randt, S. Louw, and S. Mabongwa on 18 May 2021 to try and relocate this plant or plants was unsuccessful. Flowers are visited by honey bees. The fruit is eaten by birds, notably Trumpeter Hornbills, Bycanistes bucinator Temminck (1824: livr. 48, pl. 284), at Nibela and Vervet Monkeys, Chlorocebus pygerythrus Cuvier (1821: 2) (Pooley 1978, C. Hanekom, pers. comm.), although at Nibela it is reported that monkeys and people don’t feed on the fruit (G. Linforth, pers. comm.). African Elephants, Loxodonta africana Blumenbach (1797: 125), damage trees and this has killed at least one tree at Tembe Elephant Park (C. Hanekom, pers. comm.). Nyala antelope, Tragelaphus angasii Angas (1849: 89), quickly removed fresh leaves from a cut branch at Bonamanzi Game Reserve (D. Bishop, pers. comm.) and are therefore suspected to browse on low-growing plants of the species. No young plants are known in the wild, but the species is, despite the hard endocarp of the stone, easy to grow without any special treatment besides removal of the fleshy part of the pericarp (G. Nichols, pers. comm.). Possible reasons for the apparent lack of recruits are herbivory, disease or that conditions suitable for germination and establishment on sandy soils are rare. The tree is an occasional host to the epiphytic orchids Ansellia africana Lindley (1844: sub t. 12) and Polystachya concreta (Jacquin 1760: 30) Garay & Sweet (1974: 206). Common names:— English and Afrikaans names in use include “sand ivory” and sandivoor respectively. These are also the names recommended by the Dendrological Society of South Africa (Von Dürckheim et al. 2014). There are several Zulu names recorded for Berchemia discolor in literature pertinent to KwaZulu-Natal (Pooley 1980, Moll 1981, Pooley 1993, Hutchings et al. 1996). These names are likely to be applicable to P. trachybasis. The name ubalatsheni or ubaletsheni is recorded in all of these publications and means “marks” or “make marks on the stone or rock” (A. Koopman, pers. comm.). Semantic links to the names umuma and umumu (Moll 1981, Pooley 1993, Hutchings et al. 1996), uvuka (Pooley 1993, Hutchings et al. 1996), and umbenduza (Tinley 416B in Herbs NH, NU, PRE) are not clear (A. Koopman, pers. comm.). A herbarium specimen collected at Lake Sibaya bears the name umadlozane (Cunningham 2200 in Herb. NU), which is derived from the word amadlozi and refers to ancestral spirits (A. Koopman, pers. comm.). The name umhungu is used at Nibela, which is at the northern end of Lake St. Lucia near Hluhluwe (G. Linforth, pers. comm.). This name and the similar umhungulo (Gerstner 5222 in Herb. PRE) and umhlungulo (Hutchings et al. 1996) probably mean enticing, alluring, and deceiving (A. Koopman, pers. comm.). In far northern KwaZulu-Natal an informant, M. Tembe, reports that the names vukakwabafileyo or vukakwabafile are used (C. Hanekom, pers. comm.). These names mean “to wake up at the place of those who have died” or “arise from the cemetery”, but A. Koopman (pers. comm.) suggests that their correct form may be vusabafileyo, which means “wake up the dead or unconscious”. Conservation status: —The EOO of P. trachybasis was estimated at 5951 km 2. The AOO calculated was 60 km 2 for the 2 km cell width recommended by the IUCN Standards and Petitions Committee (2019) and 350 km 2 for a 5 km cell width. The actual AOO probably lies at the lower end of this range, because even the 2 km 2 cell width includes aquatic environments and unsuitable, degraded or transformed terrestrial habitats. The distinct bark of P. trachybasis also means that accessible specimens are unlikely to be overlooked. The species occurs in 10 severely fragmented populations as defined by the IUCN (2012). Phyllogeiton trachybasis may occur in patches too small to support a viable population in the long-term and sub-populations are separated from other suitable habitat by large distances, thus genetic or demographic exchange seems unlikely. There are 70 known mature individuals in the six sub-populations surveyed during field work, namely at Bonamanzi Game Reserve (35 trees), Tembe Elephant Park and surrounds (15 trees), Hluhluwe-iMfolozi Park (8 trees), Nibela Peninsula (8 trees), False Bay Park (2 trees), and Phinda Private Game Reserve (2 trees). At least eight of these trees are in poor condition and appear to be dying and no young plants (Phyllogeiton trachybasis appears to be almost entirely confined to protected areas. Bark of the few trees growing outside of these areas is heavily used for medicinal purposes, the removal of which kills individuals or limits growth (Cunningham 2200 in Herb. NU; L. Loffler, G. Linforth, C. Hanekom, pers. comm.). Even within some protected areas trees may not be safe from harvesting (Groenewald 2010) or they may be damaged or killed by elephants (C. Hanekom, pers. comm.). It is probable that the current scarcity of trees resulted, at least in part, from the excessive stripping of bark for use in traditional medicine (locally referred to by the generic term umuthi, also spelled muti or muthi) over many years (see under “Uses” below). Taking into account that the overall number of mature individuals is small, the known sub-populations are very small and the population is declining due to natural mortality, harvesting and lack of recruitment, application of the IUCN Red List Categories and Criteria (IUCN 2012) suggest that the species should be classified as Endangered (EN) B2(v); C2a(i); D. There is an urgent need to survey populations more fully and to try and establish and address the reasons for the lack of recruitment. Uses:— On the oldest known herbarium specimens of the species (Gerstner 5222 in Herb. PRE), collected at False Bay Park in 1944, it is recorded that a tree had 90% of its bark removed by traditional healers. The label of another specimen collected in 1993 in the corridor between Ndumu Game Reserve and Tembe Elephant Park (Van Wyk BSA 748 in Herbs PRE and PRU) reads: “This is a ‘muti’ tree. The old trunk (about 1 m high) is regularly stripped of its bark—in patches”. A collection from dune forest at Lake Sibaya (Cunningham 2200 in Herb. NU) also records that the bark is heavily utilised for medicinal purposes. Trees which may belong to this species observed at Siteki, Eswatini (see under “Distribution” above) were debarked. Bark and the roots are heavily utilised east of Tembe Elephant Park and according to a local resident are mixed with material from other species to treat chest ailments (C. Hanekom, pers. comm.). There are few surviving trees in the community area surrounding Nibela at Lake St. Lucia because they have all been debarked and the majority have already died (G. Linforth, pers. comm.). At Nibela evil spirits are believed to be extracted by boiling and steaming bark, and fruit is used to treat impotence (G. Linforth, pers. comm.). At nearby False Bay Park, bark is used as a love charm (Hutchings et al. 1996). There are no records of the fruit being eaten by humans, which is surprising as the fruits of other Phyllogeiton species are popular (e.g. Pooley 1980, Van Wyk & Gericke 2000), with fruit of P. discolor even having potential in terms of commercialisation and domestication (Lusepani 1999). Additional collections (paratypes): — SOUTH AFRICA. KwaZulu-Natal: Ndumu [Ndumo] Game Reserve, (2632CD), 9 May 1956, Hancock 9 (NU!); Ndumu [Ndumo] Game Reserve, (2632CD), 23 February 1959, Tinley 416B (NH!, NU!, PRE!); 3 miles S of Makane’s Drift, (2632CD), 28 February 1968, Ross & Moll 1820 (PRE!); Ingwavuma District, Ndumu [Ndumo] Game Reserve, Matini Forest, E. area, (2732AA), 8 February 1964, Tinley 943 (NH!, NU!); Makatini Flats, Makani’s [Makane’s] Pont, (2732AA), 26 February 1968, Venter 4614 (PRE!); Corridor between Ndumu [Ndumo] and Tembe, (2732AB), 15 March 1993, Van Wyk BSA748<, Published as part of Boon, Richard G. C. & Van Wyk, Abraham E., 2023, A new species of Phyllogeiton (Rhamnaceae: Rhamneae) from Maputaland, South Africa, pp. 193-209 in Phytotaxa 585 (3) on pages 195-206, DOI: 10.11646/phytotaxa.585.3.2, http://zenodo.org/record/7690757, {"references":["Palgrave, M. (2002) Keith Coates Palgrave trees of southern Africa, 3 rd ed. Struik, Cape Town, 1212 pp.","Boon, R. [R. G. C.] (2010) Pooley's trees of eastern South Africa. A complete guide. Flora and Fauna Publications Trust, Durban, 626 pp.","Van Wyk, B. [A. E.] & Van Wyk, P. (2013) Field guide to trees of southern Africa, 2 nd ed. Struik Nature, Cape Town, 732 pp.","Du Randt, F. (2018) The sand forest of Maputaland. South African National Biodiversity Institute, Pretoria, 416 pp.","Schmidt, E. (2018) Rhamnaceae. In: Burrows, J. E., Burrows, S. M., Lotter, M. C. & Schmidt, E. (Eds.) Trees and shrubs Mozambique. Publishing Print Matters, Noordhoek, Cape Town, pp. 544 - 552.","Van Wyk, B. [A. E.], Van den Berg, E., Coates Palgrave, M. & Jordaan, M. (2011) Dictionary of names for southern African trees. Scientific names of indigenous trees, shrubs and climbers with common names from 30 languages. Briza Academic Books, Briza Publications, Pretoria, 956 pp.","Van Wyk, A. E. (1996) Biodiversity of the Maputaland Centre. In: Van der Maesen, L. J. G., Van der Burgt, X. M. & Van Medenbach de Rooy, J. M. (Eds.) The biodiversity of African plants. Kluwer Academic Publishers, Dordrecht, pp. 198 - 207.","Van Wyk, A. E. & Smith, G. F. (2001) Regions of floristic endemism in southern Africa: a review with emphasis on succulents. Umdaus Press, Hatfield, Pretoria, 199 pp.","Steenkamp, Y., Van Wyk, B. [A. E.], Victor, J., Hoare, D., Smith, G., Dold, T. & Cowling, R. (2004) Maputaland-Pondoland-Albany. In: Mittermeier, R. A., Robles Gil, P., Hoffmann, M., Pilgrim, J., Brooks, T., Goettsch Mittermeier, C., Lamoreux, J. & da Fonseca, G. A. B. (Eds.) Hotspots revisited: Earth's biologically richest and most threatened terrestrial ecoregions. Cemex & Conservation International, Washington, pp. 219 - 228.","Mucina, L. & Rutherford, M. C. (Eds.) (2006) The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria, 807 pp.","Temminck, C. J. (1824) Calao trompette Buceros bucinator. In: Nouveau recueil de planches colorieies d'oiseaux: pour servir de suite et de compleiment aux planches enlumineies de Buffon, eidition in-folio et in- 4 r de l'Imprimerie royale, 1770 (1838), vol. 2, livr. 48, pl. 284. Chez Legras Imbert et Comp, Strasbourgh, p. 99. https: // doi. org / 10.5962 / bhl. title. 51468","Cuvier, F. (1821) Le vervet. In: Geoffroy-Saint-Hilaire, E. & Cuvier, F. (Eds.) Histoire naturelle des mammiferes 3 [1824], part 24, Chez A. Belin, Paris, pp. 1 - 2. https: // doi. org / 10.5962 / bhl. title. 78766","Pooley, E. S. (1978) A checklist of the plants of Ndumu Game Reserve, north-eastern Zululand. Journal of South African Botany 44: 1 - 54. [https: // archive. org / details / journalofsouthaf 44 unse / page / n 11 / mode / 2 up]","Blumenbach, J. F. (1797) Handbuch der Naturgeschichte, 5 th ed. Johan Christian Dieterich, Gottingen, 749 pp. https: // doi. org / 10.5962 / bhl. title. 79937","Angas, G. F. (1849) Description of Tragelaphus angasii, Gray, with some account of its habits. Proceedings of the Zoological Society of London 1848: 89 - 90. [https: // www. biodiversitylibrary. org / item / 46216 # page / 125 / mode / 1 up]","Lindley, J. (1844) Ansellia africana. Edwards's Botanical Register 30: sub t. 12. [https: // www. biodiversitylibrary. org / item / 9067 # page / 48 / mode / 1 up]","Jacquin, N. J. von (1760) Enumeratio systematica plantarum, quas in insulis Caribaeis vicinaque Americes continente detexit novas, aut jam cognitas emendavit. Theodorum Haak, Leiden, 41 pp. https: // doi. org / 10.5962 / bhl. title. 737","Garay, L. J. & Sweet, H. R. (1974) Terminilogia de orchidearum Jacquinii. Orquideologia 9: 200 - 210.","Von Durckheim, H., Van Wyk, B. [A. E.], Van den Berg, E., Coates Palgrave, M. & Jordaan, M. (2014) Saklys van Suider-Afrikaanse inheemse bome / Pocket list of southern African indigenous trees, 5 th ed. Briza Academic Books, Briza Publications, Pretoria, 634 pp.","Pooley, E. S. (1980) Some notes on the utilization of natural resources by the tribal people of Maputaland. In: Bruton, M. N. & Cooper, K. H. (Eds.) Studies on the ecology of Maputaland. Rhodes University, Grahamstown and the Natal Branch of the Wildlife Society of Southern Africa, Durban, pp. 467 - 479.","Moll, E. J. (1981) Trees of Natal. Eco-lab Trust Fund, University of Cape Town, Rondebosch, 570 pp.","Pooley, E. [E. S.] (1993) The complete field guide to trees of Natal, Zululand & Transkei. Natal Flora Publications Trust, Durban, 512 pp.","Hutchings, A., Scott, A. H., Lewis, G. & Cunningham, A. B. (1996) Zulu medicinal plants an inventory. University of Natal Press, Pietermaritzburg in association with University of Zululand, KwaDlangeswa and National Botanical Institute, Claremont, 450 pp.","IUCN Standards and Petitions Committee (2019) Guidelines for using the IUCN Red List categories and criteria, version 14. Prepared by the Standards and Petitions Committee. Available from: http: // www. iucnredlist. org / documents / RedListGuidelines. pdf (accessed 23 August 2021)","IUCN (2012) IUCN Red List categories and criteria, version 3.1. IUCN Species Survival Commission, Gland, Switzerland and Cambridge, UK, iv + 32 pp. Available from: https: // portals. iucn. org / library / node / 10315 (accessed 23 August 2021)","Groenewald, Y. (2010) Ndumo reserve hit by invasion, crime. Mail and Guardian. Available from: https: // mg. co. za / article / 2010 - 10 - 15 - ndumo-reserve-hit-by-invasion-crime / (accessed 23 August 2021)","Van Wyk, B. - E. & Gericke, N. (2000) People's plants - a guide to useful plants of southern Africa. Briza Publications, Pretoria, 351 pp.","Lusepani, N. E. (1999) Reproductive biology and utilisation of Berchemia discolor (Klotzsch) Hemsley (Rhamnaceae). Unpublished MSc thesis, University of Stellenbosch, Stellenbosch, 109 pp.","Loffler, L. & Loffler, P. (2005) Swaziland tree atlas - including shrubs and climbers, 2 nd ed. South African Botanical Diversity Network Report No. 35, SABONET, Pretoria, 196 pp.","Dyer, S. T. (1988) Wood fluorescence of indigenous South African trees. IAWA Bulletin n. s. 9: 75 - 87.","Dyer, S., James, B. & James, D. (2016) Guide to the properties and uses of southern African wood. Briza Publications, Pretoria, 336 pp."]}
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33. Petalidium konkiepense Swanepoel & A. E. van Wyk 2023, sp. nov
- Author
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Swanepoel, Wessel and Van Wyk, Abraham E.
- Subjects
Petalidium ,Tracheophyta ,Magnoliopsida ,Acanthaceae ,Biodiversity ,Plantae ,Petalidium konkiepense ,Taxonomy ,Lamiales - Abstract
Petalidium konkiepense Swanepoel & A.E.van Wyk, sp. nov. (Figs 1 & 2) Diagnosis: —A woody dwarf shrub up to 1 m tall, morphologically most similar to Petalidium linifolium, differing by having the leaf lamina oblanceolate or rarely a few narrowly lanceolate (sensu Lindley), flat, subconduplicate to conduplicate towards the apex (vs. linear or narrowly lanceolate [sensu Lindley], flat, often recurved towards the apex), pale green or yellow-green and not glossy (vs. pale to bright green and glossy, covered with a glutinous secretion), with midrib and 1–4 principal lateral veins each side (vs. principal lateral veins absent), venation prominent both sides (vs. adaxially only), indumentum puberulent, abaxially often with widely spaced short-stalked glandular and robust long-stalked multi-cellular glandular trichomes in addition (vs. glabrous, except for short conical trichomes adaxially). Type: — NAMIBIA.|| Kharas Region: Bethanien District, Farm Soutkuil 181. Along track to Farm Wegdraai 179, ca. 1 km from northernmost farmstead, 2717 AD, 806 m, 26 August 2022, Swanepoel 613 (holotype WIND!; isotypes PRE!, PRU!). Woody, dwarf shrub up to 1 m tall. Stems multi-stemmed from just below or above ground level from thick rootstock or main stem, up to 150 mm in diam., bark rough and fissured, grey or dark brownish grey; older distal stems rigid, cylindrical, bark smooth or longitudinally fissured, cream or white; young stems quadrangular, green, becoming white with age, puberulent, usually with widely spaced, long, robust, multi-cellular glandular or eglandular trichomes, glabrescent, cystoliths visible. Leaves opposite and decussate on new shoots, fascicled on older stems, subsessile; lamina oblanceolate, rarely few narrowly lanceolate (sensu Lindley), flat, often subconduplicate to conduplicate towards apex, often appearing linear (when dry margin strongly involute towards midrib), up to 24.0 × 4.4 mm, pale green, semi-succulent, puberulent, usually with widely spaced short-stalked glandular and robust long-stalked multicellular glandular trichomes on margins and abaxially on venation, apex acute, margin entire, slightly incrassate, midrib and 1–4 principal lateral veins conspicuous, pale green or pale yellow, prominently raised on both surfaces, cystoliths visible on both surfaces, often conspicuous on veins and margins. Flowers solitary, axillary; bracts absent; pedicels (below bracteoles) 3–6 mm long; bracteoles ovate, symmetrical, membranaceous, 15–21 × 9–12 mm, apex attenuate, apiculate, base sub-cordate, cordate, rounded or truncate, white or cream, often violet, indigo or brown in places, venation reticulate, prominent both sides, conspicuous, green, dark green, brown, violet or indigo, puberulent abaxially, with scattered short-stalked glandular trichomes in addition, midrib rectilinear, main veins and margins with widely spaced, robust, long-stalked, multi-cellular glandular and eglandular trichomes up to 4.5 mm long, adaxially glabrous to sparsely puberulent with short-stalked glandular trichomes in places, margins sparsely lanate, cystoliths linear or linear-oblanceolate, visible on midrib and lateral veins, often conspicuous. Calyx 6.1–10.9 mm long including basal tube of 1.6–3.3 mm long, lobes 5, regular, lanceolate, acute, unequal, 2.9–7.0 × 1.2–1.7 mm; puberulous abaxially and with scattered multi-cellular stalked glandular trichomes of various lengths, strigose adaxially with short-stalked glandular trichomes in addition, margins ciliate. Corolla with narrow unexpanded portion of tube cylindrical, slightly narrowing towards expanded part, laterally slightly flattened, 26–37 mm long with lobes straightened, narrow portion 8.0– 11.8 mm long, 1.9–3.6 mm diam., expanded portion 10.0– 11.8 mm long, distal part of narrow portion and expanded portion puberulous outside with scattered short-stalked glandular trichomes in addition, inside of anticous portion towards mouth with few long stiff white hairs, throat puberulous, inside otherwise glabrous; lobes patent, obovate, apices rounded, often retuse or truncate, margins entire, upper lobes free for 80–90%, overlapping, 10.0–11.1 × 7.5–12.5 mm, lateral lobes 10.0–13.1 × 7.0– 13.1 mm, front lobe 10.0–12.6 × 8.0– 13.7 mm, lobes violet (heliotrope), mauve or blue, front lobe with two narrowly triangular nectar guides, the latter pale yellow, indigo or inconspicuous, sometimes prominent, lateral lobes with two narrowly triangular indigo markings towards base; palate chestnut towards base of expanded portion, slightly prominently transversely 6–8-ribbed. Stamens didynamous, inserted dorsally in throat, free parts of filaments fused for 1.4–2.0 mm at base, fused part prominent, adnate to tube, free parts tapering towards apex, flattened, sparingly puberulous with few short-stalked glandular trichomes, longer filament 6.3–8.0 mm long, shorter filament 4.4–5.0 mm long, outer filament trace decurrent to base of tube, puberulous; filament curtain phaulopsoid (Manktelow 2000); anthers 2-thecous, thecae oblong, equal, 3.0– 3.5 mm long with scattered short-stalked glandular trichomes, apex obtuse, base with short lobes (sagittate). Gynoecium ca. 23 mm long; ovary ovoid, laterally compressed, 2.0 × 1.0– 1.3 mm, inserted on fleshy disc, towards apex with scattered short-stalked glandular trichomes; style filiform, 14–19 mm long, puberulous with in addition very short-stalked glandular trichomes, stigma lobes linear, unequal, longer lobe 1.0– 1.6 mm long, shorter lobe ca. 0.5–1.2 mm long. Capsule elliptic, 6.5–7.0 × 3.4–5.0 mm long, tawny, glossy, glabrous; seeds not seen. Phenology: —Flowers and fruit have been recorded from June to September. Distribution and habitat: —At present, Petalidium konkiepense is only known from the area between the lower Fish and Konkiep rivers. All known populations fall within the drainage area of the Konkiep River on the farms Churutabis-Sonntagsbrunn 108, Soutkuil 181, and Bobbejaankrans 180 in southern Namibia (Fig. 3). It occurs in the Northwest Canyon Lands Landscape unit of Burke (2017) on arid hillsides and along drainage lines at elevations of 780–900 m a.s.l., ca. 155 km inland from the Atlantic Ocean. Plants grow in shallow clayey soil among limestone or shale rocks (Fig. 1) of the sedimentary Nama Group (Mendelsohn et al. 2002). Average annual rainfall in the area is less than 50 mm and falls mainly in summer (Mendelsohn et al. 2002). Conservation status: — Petalidium konkiepense is known from only one location with four small sub-populations where it is locally common. Although a brief search at various other localities with seemingly suitable habitat did not reveal any plants, it is probably more widespread than currently known. Petalidium konkiepense is here considered to be in immediate conservation danger due to its restricted distribution. Although protected in the Canyon Nature Park, prolonged droughts and rising temperatures seem to have a negative effect on the species, since in all the subpopulations most plants show signs of die-back and are in poor condition with many dead branches. Admittedly, some plants manage episodic drought by dying back and resprouting, so this is not necessarily an indication that plants are in immediate danger of dying. Hence monitoring of the plants over a longer period of time is recommended to establish the permanence of the observed die-back. Given the small extent of occurrence (EOO) of 119 km ², the single location, and the observed die-back on most of the mature individuals, a conservation status of Endangered EN B1ab(v) is proposed (IUCN 2012). Etymology:— The specific epithet refers to the Konkiep River (a tributary of the Fish River) in the Gariep Centre of Plant Endemism in southern Namibia. The name “Konkiep” (also spelled “Koin kieb”, “Konkip”, or “Koanquip”) is derived from the Khoesaan language Khoekhoegowab (Alexander 1838, Sprigade & Moisel 1904, Nienaber & Raper 1983, Raper et al. 2014). Its meaning, however, is uncertain and has most probably been lost in time. It has been claimed by some authorities that “Konkiep” is an adaptation of “Goageb” (also spelled “Goangib”), which is said to mean “the swollen twin river” (Nienaber & Raper 1983, Raper et al. 2014). However, we do not find this explanation convincing as, according to probably the earliest report on the geography of the region by Alexander (1838), Goageb (as “Gnuanuip”), is the name of a tributary of the Konkiep (as “Koanquip”) River. Notes: —In addition to P. linifolium (Fig. 4), the new species can also be confused with P. cymbiforme (Fig. 5), a species with relatively narrow leaves and a more or less similar distribution range (Fig. 3). However, the leaves of P. konkiepense are oblanceolate, rarely lanceolate (sensu Lindley) with principal lateral veins (vs. linear, rarely lanceolate [sensu Lindley], with lateral veins absent), the bracteoles are membranaceous, white or cream in colour (vs. cartilaginous, green, or pale green), and the colour of the corolla of P. konkiepense is violet (“heliotrope”), mauve or blue (vs. white or cream). Some of the morphological features to distinguish among P. konkiepense, P. linifolium, and P. cymbiforme are provided in Table 1. Also see Figs 4 & 5. All the mentioned species are from the infrageneric group composed of plants with regular, five-parted calyces (Obermeijer 1936, Tripp et al. 2017). Additional specimens examined (paratypes): — NAMIBIA, || Kharas Region: Farm Churutabis-Sonntagsbrunn 108, at entrance gate to Fish River Lodge, 2717AD, 784 m, 27 August 2022, Swanepoel 615 (WIND!); On Soutkuil, 2717CB, 30 June 1986, Craven 2512 (WIND!); Farm Bobbejaankranz [Bobbejaankrans], on road from Soutkuil to house, 2717CB, 22 September 1989, Craven 3493 (WIND!); Bethanien District, Farm Soutkuil No. 181, 2717CB, no date, Owen-Smith 1203 (WIND!); Farm Soutkuil 181, track between Soutkuil and Farm Wegdraai 179, 5.7 km from northernmost farmstead on Soutkuil, 2717CB, 894 m, 26 August 2022, Swanepoel 614 (WIND); Farm Soutkuil 181, 2717CD, 14 July 1988, Craven 3332 (WIND!); Farm Soutkuil 181, approaching Soutkuil house from southern side, 2717CD, 1 July 1991, Craven 3936 (WIND!)., Published as part of Swanepoel, Wessel & Van Wyk, Abraham E., 2023, Petalidium konkiepense (Acanthaceae), a new species from Namibia, pp. 29-38 in Phytotaxa 585 (1) on pages 30-37, DOI: 10.11646/phytotaxa.585.1.3, http://zenodo.org/record/7672906, {"references":["Pretoria, 1231 pp. IUCN (2012) IUCN red list categories and criteria: Version 3.1. 2 nd edn. Gland, Switzerland and Cambridge U. K., iv + 32 pp. Manktelow, M. (2000) The filament curtain: a structure important to systematics and pollination biology in the Acanthaceae. Botanical","https: // doi. org / 10.1111 / j. 1095 - 8312.1863. tb 01056. x Beentje, H. (2016) The Kew plant glossary: an illustrated dictionary of plant terms, 2 nd ed. Kew Publishing, Kew, 184 pp. Burke, A. (2017) Biodiversity zoning in the Greater Fish River Canyon Landscape in southern Namibia. Namibian Journal of Environment","https: // doi. org / 10.1006 / bojl. 1999.0309 Mendelsohn, J., Jarvis, A., Roberts, C. & Robertson, T. (2002) Atlas of Namibia. Philip, Cape Town, 200 pp. Nees von Esenbeck, C. G. (1832) Acanthaceae India Orientalis. In: N. Wallich (Ed.), Plantae Asiaticae rariores: or descriptions and figures of a select number of unpublished East Indian plants, vol. 3. Treuttel & Wurtz, London, pp. 41 - 117.","Alexander, J. E. (1838) An expedition of discovery into the interior of Africa, through the hitherto undescribed countries of the Great","https: // doi. org / 10.5962 / bhl. title. 468 Nienaber, G. S. & Raper, P. E. (1983) Hottentot (Khoekhoen) place names. Butterworth, Durban, 243 pp. Obermeijer, A. A. (1936) The South African species of Petalidium. Annals of the Transvaal Museum 18: 151 - 162. Raper, P. E., Moller, L. A. & Du Plessis, T. (2014) Dictionary of southern African place names. Jonathan Ball, Johannesburg, 566 pp. Schinz, H. (1926) Acanthaceae. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zurich 71: 145 - 146. Sprigade, P. & Moisel, M. (Eds.) (1904) Kriegskarte von Deutsch-Sudwestafrika 1: 800 000. Dietrich Reimer, Berlin, set of eight maps","Tripp, E. A., Tsai, Y. E., Zhuang, Y. & Dexter, K. G. (2017) RADseq dataset with 90 % missing data fully resolves recent radiation of Petalidium (Acanthaceae) in the ultra-arid deserts of Namibia. Ecology and Evolution 7: 1 - 17. https: // doi. org / 10.1002 / ece 3.3274"]}
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34. Foreword
- Author
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van Wyk, Abraham E., primary
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- 2018
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35. Senecio namibensis Swanepoel & A. E. van Wyk 2022, sp. nov
- Author
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Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, and Van Wyk, Abraham E.
- Subjects
Tracheophyta ,Magnoliopsida ,Asterales ,Senecio namibensis ,Senecio ,Biodiversity ,Asteraceae ,Plantae ,Taxonomy - Abstract
Senecio namibensis Swanepoel & A.E.van Wyk, sp. nov. (Figs 1–3) Diagnosis: —Dwarf shrub up to 0.4 m high, morphologically most similar to Senecio englerianus and S. flavus: from S. englerianus it differs in having the leaf blade cordate to suborbicular or reniform (vs. cordate, suborbicular, reniform, ovate or oblate); blade base cordate to deeply cordate (vs. cordate-reniform or truncate); capitula radiate (vs. discoid); involucre usually shorter and narrower: 5.3–7.4 mm long, 3.5–4.0 mm diam. (vs. 6.3–8.0 mm long, 4.4–5.6 mm diam.); from S. flavus it differs in having the capitula distinctly radiate (vs. disciform or obscurely radiate; ray florets scarcely longer than involucre); involucre usually shorter and wider: 5.3–7.4 mm long, 3.5–4.0 mm diam. (vs. 7.0– 9.5 mm long, 2.7–2.9 mm diam.); pappus bristles free, non-fluked and lacking hooklike apical appendages [vs. ca. 33%—according to Coleman et al. (2003) and Milton et al. (2022) —of pappus bristles connate and fluked—see “Materials and methods” for definition of “fluked” bristles—with grappling hook-like apical appendages]. Type: — NAMIBIA. Kunene Region: 1812 (Sanitatas), Namib Desert, gneiss ridge, 3 km north of Khumib River and 4 km east of Skeleton Coast Park boundary (–DA), 377 m a.s.l., 23 May 2022, Swanepoel 585 (holotype WIND!; isotypes PRE!, PRU!). Single-stemmed annual or short-lived perennial dwarf shrub, glabrous, herbaceous to succulent, up to 0.4 m high, cushion-forming when perennial. Branches succulent, brittle, pale green, glaucous, short, 10–35 mm long before rebranching. Leaves alternate and spirally arranged, fleshy to succulent, pale green or grey-green, glaucous, lower and middle cauline leaves petiolate with blade cordate to suborbicular or reniform, ca. flat, apex acute or rounded, base subcordate to deeply cordate, margins coarsely dentate with 5 or 9 teeth each side or almost entire, veining palmately, inconspicuous, not prominent, 5–40 × 8–45 mm, fleshy, up to 2.5 mm thick; petiole 3–38 mm long, up to 2 mm diam., brittle, pale green, angle with blade abaxially ca. 120 degrees (ca. patent), blade appearing peltate due to deeply cordate base; upper cauline leaves sessile, sub-amplexicaul to amplexicaul, irregular, up to 12 × 12 mm. Inflorescences axillary or terminal, capitula solitary or cymously twice-forked, 15–95 mm long, pale green. Peduncle 11–50 mm long, 0.6–0.8 mm in diam. (at capitulum 1.0– 1.2 mm diam.), erect, with up to 4 lanceolate or narrowly triangular bracts towards capitulum, ca. 1 mm long, calyculus bracts 5–7, lanceolate or narrowly triangular, 0.8–2.0 mm long. Capitula 2 or 3 per inflorescence, heterogamous with female ray florets and fertile hermaphrodite disc florets, other peripheral florets (between ray florets) similar to disc florets, radiate, slightly convex, 9–11 mm diam. (including rays), yellow-flowered. Receptacle flat, indistinctly alveolate, convex and verrucose when dry. Involucre cupuliform, 5.5–6.3 mm long, 3.5–4.0 mm diam., involucral bracts 10–13, lanceolate, concave in transection, free, 5–6 × 0.7–1.1 mm, herbaceous, margins membraneous, acute, pale green with a purple tinge, glaucous, patent to reflexed when in fruit. Ray florets 3–6, yellow, corolla 5.0– 7.9 mm long (including ray), tube terete, ca. 0.4 mm diam.; ray yellow, elliptic-oblong with 4 or 5 darker longitudinal lines, 2.5–4.4 mm long, 40–55% as long as the involucre, apex rounded or truncate, entire or with 1–4 denticulate teeth, glabrous; ovary oblong, terete, white, densely papillate (not twin hairs), 1.4–1.8 mm long, 0.5 mm diam., ovule oblong, 1.3–1.5 mm long, 0.3 mm diam.; style 2.9–3.2 mm long, ca. 0.2 mm diam., terete; branches ca. 0.8 mm long, flattened, grooved, minutely papillate (sweeping hairs) towards truncate apex; pappus copious, ca. 52, minutely barbellate bristles, 2.5–3.6 mm long, of “ordinary” type (sensu Drury & Watson 1966), erect, persistent, white. Cypselae oblong, terete, angular, grooved, dark brown, white-papillate, ca. 2.4 mm long, ca. 0.5 mm wide. Disc florets ca. 30, pale yellow-green, corolla 3.9–4.5 mm long; tube cylindrical, 1.4–1.6 mm long, 0.4 mm diam.; limb ca. 2.5 mm long, gradually widening from 0.4 mm to 0.8 mm diam. at apex; lobes 5, deltoid-ovate, 0.5–0.8 mm long, thickened abaxially towards apex, glabrous; anthers ca. 1.8 mm long including ovate apical appendage; filament collar balusterform; style ca. 3.8 mm long, 0.2 mm diam., terete, branches as for ray florets; ovary narrowly oblong, densely papillate, ca. 1.8 mm long, 0.5 mm diam., terete, ovary, ovule, pappus and cypselae as for ray florets. Phenology: —Flowers and fruit were recorded from February to September. Distribution, habitat, and ecology: — At present Senecio namibensis is known only from ten localities in the Namibian part of the Namib Desert, from the Khumib River in the north to the Rössing Mountains in the south (Fig. 4). This part of the Namib Desert falls mainly in the Namib zone of the Kaokoveld Centre of Endemism (Van Wyk & Smith 2001). Senecio namibensis occurs approximately 20–32 km from the coast in the north to 30–60 km in the south, with a maximum distance of 75 km in the centre of its distribution at a locality south of the Huab River. It occurs in small colonies of a few plants each in sandy gravel at the base of rocks and boulders in hilly areas, at elevations of 150–500 m a.s.l., with annual average rainfall up to 100 mm (Mendelsohn et al. 2002). Conservation status: — Although rare and only known from a small area, Senecio namibensis is probably not threatened at present. The entire known population occurs within either uninhabited or protected areas (Skeleton Coast and Dorob National Parks, including several conservancies). No signs of damage caused by animals or humans were present on any of the in situ specimens examined. The extent of occurrence is estimated at Etymology: —The specific epithet refers to the Namib Desert, which, in its broadest definition, stretches along the Atlantic Ocean from Saõ Nicolau (Bentiaba) in Angola through Namibia to the Olifants River in South Africa (Seely 2004, Goudie & Viles 2015). Notes: —The distribution of Senecio namibensis does not overlap with that of its two suggested nearest relatives. Senecio namibensis occurs to the east (further inland) of the range of S. englerianus and to the west of S. flavus (Fig. 4). Some of the more prominent morphological features to distinguish among the three species are provided in Table 1. Milton et al. (2022) report S. englerianus as being dimorphic for capitulum-type (mostly non-radiate, occasionally radiate), citing as reference Jürgens et al. (2021), which refers to the “https://southernafricanplants.net” website. On the Senecio englerianus (as “ Senecio engleranus ”) page of this website, a photograph of a plant with yellow rays is shown (FotoID: 10798, E. Erb, Namibia, 16-08-2006), probably the basis for the statement that the capitula in S. englerianus are dimorphic. However, the plant in the photograph almost certainly represents S. namibensis, although it is not possible to confirm this based on a photograph alone. Senecio vulgaris Linnaeus (1753: 867) from the British Isles has also been reported as being either radiate or non-radiate. In this case, the polymorphism arose by introgression of a cluster of regulatory genes from the radiate S. squalidus Linnaeus (1753: 869) (originating from Sicily) into the non-radiate S. vulgaris after the introduction and spread of the former from Europe to the British Isles (Kim et al. 2008). Due to the absence of related species of Senecio in the area of distribution of S. englerianus, from which it could have obtained radiate capitula, the possibility of S. namibensis being a radiate variant of S. englerianus is ruled out as highly unlikely. In support of separate species status for S. namibensis is also the combination of other morphological differences between it and S. englerianus, notably the shorter and narrower involucre (Table 1). Unrelated asteraceous species within the range of Senecio namibensis with which it can be confused, are Dauresia alliariifolia (Hoffmann 1888: 280) Nordenstam & Pelser (2005: 76) and Engleria africana Hoffmann (1888: 273), due to similarities in leaf characters. However, Dauresia alliariifolia has white branches (vs. green), an ecalyculate involucre (vs. calyculate) and discoid white- or yellow-flowered capitula (vs. radiate, yellow-flowered). Engleria africana has much larger capitula, ca. 12 mm long (vs. 5.3–7.4 mm), the involucres consist of three rows of involucral bracts (vs. one row) and the peripheral florets lack rays (vs. ray florets present). Additional specimens examined (paratypes): — NAMIBIA. Kunene Region: 1812 (Sanitatas): Khumibrivier se droë loop (–DC), 7 May 1962, Kotze 124 (WIND!). 2013 (Unjab mouth): Huab River area north of Gaias (–DB), 27 August 1977, Craven 510 (WIND!); Foot of mountains along Huab River (–DC), 12 August 1979, Müller & Loutit 1164 (WIND!). 2014 (Welwitschia): Damaraland, between Huab and Mikberg (– CA), 11 September 1993, Günster 9391 (WIND!). Erongo Region: 2113 (Cape Cross): 30 km east of Ugabmond (– BB), 16 August 1979, Müller & Loutit 1213 (WIND!). 2114 (Uis): Messum crater (– AC), 15 May 2000, Hachfeld 119244 (WIND!). 2214 (Swakopmund): Rössingberge (–DB), 27 February 1958, Merxmüller & Giess 1735 (WIND!); Westseite Rössing (–DB), 8 May 1969, Homann, Benseler & Mittendorf 23 (WIND!).
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36. Petalidium mannheimerae Swanepoel, Nanyeni & A. E. van Wyk 2022, sp. nov
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Swanepoel, Wessel, Nanyeni, Leevi, and Van Wyk, Abraham E.
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Petalidium ,Tracheophyta ,Magnoliopsida ,Petalidium mannheimerae ,Acanthaceae ,Biodiversity ,Plantae ,Taxonomy ,Lamiales - Abstract
Petalidium mannheimerae Swanepoel, Nanyeni & A.E.van Wyk, sp. nov. (Figs 3 & 4) Diagnosis:— A woody dwarf shrub up to 1.5 m tall, morphologically most similar to Petalidium lucens and P.parvifolium differing from both in having the lamina semi-succulent, subconduplicate to conduplicate, recurved towards apex, and with lateral veins indistinct or absent (vs. lamina not succulent, flat, lateral veins distinct); from P. lucens in having indumentum on vegetative parts puberulent and on leaf margins having widely spaced, robust, stalked glands (vs. dense short simple or sessile stellate trichomes [with 2 or 3 branches], usually with isolated dendritic trichomes in addition, glabrescent), corolla lobes white (vs. mauve or light blue); from P. parvifolium in having indumentum on vegetative parts puberulent (vs. scattered sessile glandular trichomes), leaf margins with widely spaced, robust, stalked glandular trichomes (vs. trichomes absent), corolla white (vs. mauve, white or white with lilac tinge). Type: — NAMIBIA. || Kharas Region: Karasburg District, Aussenkjer [Aussenkehr] 147 Farm: The mountain on the bank of the Orange River less than a km from the turn off to the right as you come in from the Sjambok entrance, 2817 CB, 14 September 2014, Nanyeni 936 (holotype WIND!; isotypes PRE!, PRU!). Petalidium sp. A in Snijman (2013: 164). Dense, woody, dwarf shrub to 1.5 m tall. Stems multi-stemmed from just below or above ground level from a thick rootstock or main stem, up to 140 mm in diam., bark smooth, cream, grey-white or grey-black; older distal stems rigid, cylindrical, bark smooth or longitudinally fissured, cream, grey-brown or yellow-brown; young stems quadrangular, green, puberulent, usually with widely spaced, long, robust, multi-cellular trichomes, glabrescent, cystoliths visible, linear or linear-oblanceolate. Leaves opposite and decussate, subsessile or with petioles up to 1.5 mm long; lamina narrowly obovate, oblanceolate, elliptic or suborbicular, subconduplicate to conduplicate, recurved towards apex, 10– 24 × 4–16 mm, green, semi-succulent, puberulent, apex acute, rounded or emarginate, base attenuate, decurrent onto petiole almost to stem, margin entire with widely spaced, robust, stalked glandular trichomes; midrib conspicuous, prominent abaxially, lateral veins indistinct or absent, cystoliths conspicuous on both sides, especially in herbarium material. Flowers solitary, axillary, supporting leaf (“bract”) similar to foliage leaves; pedicels (below bracteoles) 3–4 mm long; bracteoles ovate, usually asymmetrically, membranaceous, apex attenuate, usually with 1–5, long, sharp, robust, multicellular trichomes, base cordate or truncate, pale green, yellow-green or mauve-green, when dry also buff or brown, venation usually conspicuous, pale green, dark green or mauve-green, prominent especially adaxially, 13–15 × 7–9 mm, puberulent both sides, margins lanate and sometimes with widely spaced short stalked glandular and or long, robust multicellular trichomes, cystoliths visible on midrib towards base. Calyx 5–6 mm long including basal tube of 1–2 mm, puberulous abaxially towards base and with scattered very short stalked glandular trichomes abaxially, strigose adaxially, margins puberulous-ciliate; lobes 5, regular, linear-triangular, acute, 3.3–4.0 × 1.0– 1.2 mm. Corolla with narrow unexpanded portion of tube cylindrical, slightly widening towards throat, slightly flattened, 22–25 mm long with lobes straightened, narrow portion ca. 5–7 mm long, 2.0– 2.5 mm diam., expanded portion 8–10 mm long, corolla white, inside of expanded portion pale maroon, chestnut or yellow, distal half sometimes white, lobe traces (veins) including herringbone pattern on anticous portion white, front lobe with two pale yellow or cream narrowly triangular nectar guides or guides absent, other lobes sometimes with pale maroon markings towards base, outside puberulous, towards mouth with few long stiff white hairs, throat puberulous, otherwise glabrous; lobes patent, obovate, apices rounded, often retuse, margins entire or irregularly denticulate to crenate, upper lobes overlapping, free, ca. 6 × 9 mm, lateral lobes ca. 8 × 8 mm, front lobe ca. 9 × 7 mm; palate prominently transversely ca. 7-ribbed. Filaments didynamous, inserted dorsally in throat, filaments fused for ca. 1.8 mm at base, fused part prominent, adnate to tube, free parts tapering towards apex, flattened, sparingly puberulous with few short stalked glandular trichomes, long filament 6.1–7.3 mm long, short filament 4.3–4.8 mm long, outer filament trace decurrent to base of tube, puberulous; filament curtain phaulopsoid (Manktelow 2000); anthers 2-thecous, thecae oblong, equal or subequal, 2.1–2.3 mm long with scattered short stalked glandular trichomes, apex rounded, with minute spurs at base, 0.2 mm long. Gynoecium ca. 14 mm long; ovary ovoid, laterally compressed, 2.0 × 1.3 mm, inserted on fleshy disc, glabrous; style filiform, ca. 10 mm long, puberulous, stigma lobes linear, slightly flattened, unequal, longer lobe ca. 0.8 mm long, shorter lobe ca. 0.4 mm long. Capsule elliptic, 6.5–7.0 × 3.4–5.0 mm long, tawny, glossy, glabrous. Phenology:— Flowers have been recorded in August and September; fruits throughout the year. Distribution and habitat:— At present, Petalidium mannheimerae is known in Namibia from the vicinity of Aussenkehr in the Orange River Valley and in South Africa from ca. 30 km south of Vioolsdrif to near Eksteenfontein in the Richtersveld (Fig. 2). It occurs 92–110 km from the Atlantic Ocean on hillsides and drainage lines, at elevations of 134–187 m in Namibia and in South Africa at 551–700 m a.s.l. Average annual rainfall in the area is less than 50 mm (Mendelsohn et al. 2002). Conservation status:— Petalidium mannheimerae has been recorded at seven localities in an area of ca. 60 × 15 km where it is locally occasional to common. Although a brief search at various other localities with seemingly suitable habitat did not reveal any plants, it is probably more widespread than currently known. Although protected in the Aussenkehr Nature Park in Namibia, small stock farming on the banks of the Orange River might lead to overutilization by domestic goats belonging to local inhabitants. In South Africa, grazing by small stock and even a heavily grazed population is noted on herbarium sheets by two collectors (Jürgens 22952, Steyn 2127). At Swartkop, mining activities might pose a threat as P. mannheimerae occurs very close to and even in the mining area. A recent visit to the area of distribution revealed many dead woody plants, recently died, probably due to prolonged droughts in the area. It is possible that some of these might be referred to the new species. Petalidium mannheimerae is here provisionally ranked as Vulnerable VU D1 (IUCN 2012). Etymology:— The specific epithet honours Mrs Coleen Anne Mannheimer [1957–], renowned Namibian botanist and former curator of the National Herbarium of Namibia (WIND). She has collected widely in Namibia and has authored or co-authored several publications on the Namibian flora. Coleen introduced one of us (LN) to botany and botanical fieldwork and has since been a mentor to him in the herbarium and in the field. Her knowledge of the Namibian flora is exceptional and her ability to develop and encourage future Namibian botanists has been profound. Notes:— Some of the morphological features to distinguish among Petalidium mannheimerae, P. lucens, and P. parvifolium are provided in Table 1; also see Figs 4–6. Petalidium mannheimerae can also be confused with P. cymbiforme and P. linifolium due to similarities in habit and flower morphology. However, these species have a different indumentum and linear leaves, with the corolla of P. linifolium pale mauve (vs. white) and the venation of the bracteoles of P. cymbiforme inconspicuous (vs. usually conspicuous). All the mentioned species are members of Petalidium sect. Petalidium (sensu Meyer 1968), a group composed of plants with regular, five-parted calyces (Obermeijer 1936; Tripp et al. 2017). Additional specimens examined (paratypes):— NAMIBIA. || Kharas Region: Karasburg District, Aussenkjer [Aussenkehr] 147 Farm: The mountain on the bank of the Orange River less than a km from the turn off to the right as you come in from the Sjambok entrance, 2817 CB, 12 August 2018, Nanyeni 1371, 1372 (WIND!); Mountain slope, 250 m downstream of Sambok River Mouth, Farm Aussenkehr 147, 2817 CB, 134 m, 23 February 2022, Swanepoel 571 (WIND!). SOUTH AFRICA. Northern Cape Province: Richtersveld. Kahams area east of Stinkfonteinberge, east of kloof running down from Cornellsberg, 2817 CA, 600 m, 5 September 1977, Oliver, Tölken & Venter 665 (PRE!); 12 miles from Stinkfontein on way to Vioolsdrif in Richtersveld, 2917 CB, ca. 700 m, 15 November 1971, Werger 1511 (PRE!); Richtersveld. Vanzylsrivier, 2817 CB, 580 m, 25 September 1987, Jurgens 22952 (PRE!); Namaqualand District. Richtersveld, southeast of Sunvalley camp site, 2817 CB, 551 m, 8 August 2011, Steyn 1847 (PRE!); Richtersveld. Near Stinkfontein, 2817CD, 14 September 1961, Van Breda 1497 (PRE!); Richtersveld. Road between Stinkfontein & Modderdrift, 20 miles from Stinkfontein, 2817CD, 15 September 1961, Hardy 675 (PRE!); Vioolsdrif, Klein Helskloof, 20 km northeast of Eksteenfontein, 2817CD, 9 September 2002, Venter & Venter 9800 (PRE!); Namakwaland. 53 km vanaf Steinkopf pad na Vioolsdrif, 2817DC, 27 August 1983, Van Wyk 6513 (PRE!, PRU!); Vioolsdrif District. Nababeepsberg (Swartberge) in deep gorge below Helshoogte on eastern side of main road, 2817DC, 27 August 1988, Williamson 3912 (PRE!); Namakwaland. Swartbergmyn tussen Steinkopf en Vioolsdrif, 2817 DD, 27 August 1983, Van Wyk 6532 (PRE!, PRU!); Swartkop Mine, 2817 DD, 643 m, 7 August 2018, Nanyeni 1370 (PRE!, WIND!); Namaqualand District. Wyepoort River Valley, 2917 BA, 598 m, 9 October 2015, Steyn 2127 (PRE!)., Published as part of Swanepoel, Wessel, Nanyeni, Leevi & Van Wyk, Abraham E., 2022, Petalidium mannheimerae (Acanthaceae), a new species from Namibia and South Africa, with notes on the taxonomic identity of P. parvifolium, pp. 1-13 in Phytotaxa 561 (1) on pages 5-11, DOI: 10.11646/phytotaxa.561.1.1, http://zenodo.org/record/7052737, {"references":["Snijman, D. A. (2013) Acanthaceae, In: Snijman, D. A. (ed.) Plants of the Greater Cape Floristic Region, vol. 2: the Extra Cape flora. Strelitzia 30. South African National Biodiversity Institute, Pretoria, pp. 162 - 164.","Manktelow, M. (2000) The filament curtain: a structure important to systematics and pollination biology in the Acanthaceae. Botanical Journal of the Linnean Society 133: 129 - 160. https: // doi. org / 10.1111 / j. 1095 - 8339.2000. tb 01539. x","Mendelsohn, J., Jarvis, A., Roberts, C. & Robertson, T. (2002) Atlas of Namibia. Philip, Cape Town, 200 pp.","IUCN (2012) IUCN red list categories and criteria: Version 3.1. 2 nd edn. Gland, Switzerland and Cambridge U. K., iv + 32 pp.","Meyer, P. G. (1968) Acanthaceae. Prodromus einer Flora von Sudwestafrica 130: 1 - 65.","Obermeijer, A. A. (1936) The South African species of Petalidium. Annals of the Transvaal Museum 18: 151 - 162.","Tripp, E. A., Tsai, Y. E., Zhuang, Y. & Dexter, K. G. (2017) RADseq dataset with 90 % missing data fully resolves recent radiation of Petalidium (Acanthaceae) in the ultra-arid deserts of Namibia. Ecology and Evolution 7: 1 - 17. https: // doi. org / 10.1002 / ece 3.3274"]}
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37. Petalidium mannheimerae (Acanthaceae), a new species from Namibia and South Africa, with notes on the taxonomic identity of P. parvifolium
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SWANEPOEL, WESSEL, primary, NANYENI, LEEVI, additional, and VAN WYK, ABRAHAM E., additional
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38. The correct names for species of Aloe sect. Chortolirion ( Asphodelaceae : Alooideae )
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Klopper, Ronell R., Smith, Gideon F., Figueiredo, Estrela, Grace, Olwen M., and van Wyk, Abraham E.
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- 2013
39. A New Species of Pavetta (Rubiaceae) from South Africa
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Siebert, Stefan J., Retief, Elizabeth, and van Wyk, Abraham E.
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40. (2144) Proposal to conserve the name Kumara ( Asphodelaceae ) with a conserved type
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Klopper, Ronell R., Smith, Gideon F., and van Wyk, Abraham E.
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41. (2129) Proposal to conserve the family name Asphodelaceae ( Spermatophyta: Magnoliidae: Asparagales )
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Klopper, Ronell R., Smith, Gideon F., and van Wyk, Abraham E.
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- 2013
42. Commiphora omundomba Swanepoel & Weeks 2022, sp. nov
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Swanepoel, Wessel, Weeks, Andrea, and Van Wyk, Abraham E.
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Sapindales ,Tracheophyta ,Magnoliopsida ,Commiphora omundomba ,Biodiversity ,Plantae ,Burseraceae ,Commiphora ,Taxonomy - Abstract
Commiphora omundomba Swanepoel & Weeks, sp. nov. (Figs 1–3) Diagnosis: —Differs from C. dinteri in the terminal leaflets being oblanceolate or narrowly obovate (vs. obovate); lateral leaflets oblanceolate, narrowly obovate, obovate, elliptic, oblong, or suborbicular (vs. broadly elliptic or suborbicular); ratio length of terminal leaflets to width being 1.9–3.2:1 (vs. 1–2:1); ratio length of terminal leaflets to lateral leaflets being 1.1–1.4:1 (vs. 1.5–2.9:1); leaflet margins often entire (vs. always toothed); calyx eglandular (vs. glandular); number of calyx lobes and petals 3 or rarely 4 (vs. 4); number of disc lobes 3 or rarely 4 (vs. 4); in male flowers distal part of disc lobes adnate to hypanthium, obscurely bifid at apex (vs. distal part not adnate to hypanthium, distinctly bifid at apex); pseudo-aril with commissural arms shorter, extending 25–65% the length of putamen (vs. longer, 75–95%). Type: — NAMIBIA. Kunene Region: Kunene River Valley opposite Hartmann Mountains, (–AB), 170 m, 2 May 2017, Swanepoel 347 (holotype WIND!; isotype PRU!). Deciduous, dioecious shrub-like tree, up to 2.5 m tall, 0.5–3.5 m diam. (Fig. 1A), sometimes prostrate (Fig. 1B). Trunk simple and short (Fig. 2C), up to 0.2 m long, 0.3 m diam., or branching repeatedly above ground level, appearing succulent; stems relatively thick, with many thinner side branches. Bark pale grey or reddish grey, brown, greybrown or reddish brown, with slightly raised, almost parallel longitudinal ridges on stems and older branches, not peeling (Fig. 2C). Branches and branchlets glabrous with few small, prominent lenticels, not spine-tipped; dwarf lateral branchlets scarred. Exudate white, viscous, scanty, drying to form a hard, pale yellow, translucent resin. Leaves trifoliolate, clustered distally on branches and on dwarf lateral shoots but spirally arranged on actively elongating shoots, subsessile or petiolate, glabrous, pale green, not or slightly glossy; lamina of terminal leaflets oblanceolate or narrowly obovate, apex obtuse or rounded, base cuneate or attenuate, 5–27 × 3–11 mm, length to width ratio 1.9–3.2:1; lamina of lateral leaflets oblanceolate, narrowly obovate, obovate, elliptic, oblong or suborbicular, often asymmetric, apex obtuse, base obtuse or cuneate, 4–10 × 2–6 mm; leaflet margins entire, crenate or crenate-serrate towards apex with up to 5 teeth each side, midrib conspicuous abaxially, prominent towards base on both sides, leaflets sessile, length of terminal to length of lateral leaflets ratio 1.1–1.4:1; petiole usually grooved adaxially, 0.5–34 mm long, obcordate or reniform, rarely obovate in transverse section, vascular bundles 3 or 4, sectional dimensions 0.5–0.7 × 0.6–0.8 mm. Inflorescences flowers axillary, solitary or clustered. Flowers sessile, unisexual, perigynous, appearing before or with new leaves or occasionally flowering continuously until leaves have been shed. Bracts obovate, succulent, ± 0.9 × 0.6 × 0.4 mm, glabrous. Calyx maroon or maroon-green, eglandular, glabrous, lobes 3(4), ovate, acute. Petals 3(4), spreading-ascending or spreading-recurved, tip minute and inflexed, yellow-green, glabrous. Disc cylindrical with 3(4) lobes. Male flowers 2.5–4.1 mm long, calyx 1.7–2.6 mm long, calyx lobes 0.6–1.0 mm long, petals oblanceolate or narrowly elliptic, 2.2–4.2 × 1.0– 1.8 mm; disc fleshy, folded and glandular on inside, lobes obscurely bifid at apex, distal part adnate to hypanthium; stamens 6(8), filaments subterete, flattened and broadened over lower part, 3(4) long stamens with filaments 1.4–2.1 mm long, inserted on margin of disc lobes, 3(4) short stamens with filaments 0.5–1.4 mm long, inserted between lobes on margin of disc, anthers ± 0.8 mm long, equal in length on short and long stamens; gynoecium rudimentary. Female flowers 2.4–3.0 mm long, calyx 1.7–2.3 mm long, calyx lobes ± 0.8 mm long, petals broadly oblanceolate, 2.2–2.6 × 1.1–1.4 mm; staminodes 6(8), alternately long and short, inserted on disc margin, disc lobes not bifid; ovary ovoid, half-inferior, style relatively short, ovary and style glabrous, style sparsely glandular, stigma obscurely 3(4)-lobed, 1.3–1.8 mm long, 0.5–0.6 mm diam. Fruit a drupe, ovoid, obovoid or ellipsoid, apiculate, slightly flattened, asymmetrical, fertile locule often bent over towards sterile locule, 9.4–11.4 × 6.7–7.3 × 4.9–5.6 mm; pericarp 2-valved; exocarp glabrous, glandular, glutinous, maroon in ripe fruit; mesocarp not very fleshy; stone flattened, asymmetrically ovoid, obovoid or subglobose with one fertile and one sterile locule, slightly rugose; 5.5–8.1 × 4.8–5.5 × 3.1–3.8 mm; fertile locule convex in sutural and apical view; sterile locule dorsally ridged, slightly convex or varying from convex at base to concave towards apex in sutural view, ± triangular in apical view; suture rectilinear but curved towards sterile locule at apex; angle between locules at apex ± 35°–72°; pseudo-aril orange or red, fleshy, cupular, covering 15–40% of fertile locule and 20–45% of sterile locule, with 2 commissural arms and two short facial lobes, extent of commissural arms (relative to length of stone with pseudo-aril removed) 25–65%, facial lobes convex or triangular, 0.4–1.0 mm on fertile locule, 0.9–1.2 mm on sterile locule, lobe on fertile locule sometimes absent; apical pits small. Phylogeny: — Commiphora omundomba is part of the ‘Gariepensis’ clade of Commiphora (Gostel et al. 2016), which comprises a group of 15 unarmed and largely pachycaulescent species endemic to southwestern Africa (Fig. 4). The nested relationships among these species are mostly well supported (90–100% bootstrap support) except for the three nodes subtending C. omundomba, including its sister-relationship with C. buruxa, which are only moderately supported (80–82%). Both C. omundomba and C. buruxa share morphological traits that may reflect a close or mostrecent common ancestry, despite their disjunct ranges in the Kaokoveld and Gariep Centres of Endemism, respectively. Both are dioecious, shrub-like trees bearing viscous and opaque white to cream coloured exudate and glabrous trifoliolate leaves with variably toothed to entire margins, as well as petioles that can have reniform cross sections. However, flower and fruit structure are more divergent, including differences in the number of petals and the sculpturing of the pseudaril, which suggests that the current molecular phylogenetic hypothesis of a sister relationship between C. omundomba and C. buruxa may be provisional, pending future and more extensive phylogenomic investigations of this clade. Notably, species of the ‘Gariepensis’ clade have radiated over the last ca. 16 Ma (Gostel et al. 2016), most likely under extreme environmental selection pressures that have resulted in convergent, water-conserving morphologies. Phenology: — Commiphora omundomba flowers from April to June. Fruits were encountered on plants from April to July. Distribution and habitat: — Commiphora omundomba is presently known from various localities in the coastal zone of southwestern Angola, from Santa Maria and ± 15 km inland southwards to the Kunene River in the Iona National Park and east of the dune belt, to ± 90 km inland. In the vicinity of Moçamedes it occurs on top of the coastal sandstone cliffs (Figs 1B, 5). In Namibia the new species is found from the Kunene River southwards to near Puros and eastwards to the Hartmann and Etendeka Mountains, which form part of the Great Escarpment. The range of C. omundomba in Angola and Namibia falls within the Kaokoveld Centre of Plant Endemism (Van Wyk & Smith, 2001); this extremely arid (average annual rainfall Commiphora omundomba is rare to locally common and occurs with several other species of Commiphora on mountain slopes and level areas, in arid savanna and desert shrubland at elevations of 5–1300 m. Conservation status: — Commiphora omundomba is not under any threat as the plants are located in remote, sparsely populated areas. Etymology and common names: —The specific epithet is the local Ovahimba vernacular name (a dialect of Otjiherero) for the new species. As vernacular names in English and Afrikaans we propose Iona corkwood and ionakanniedood. Notes: — Commiphora omundomba has hitherto escaped recognition as a distinct species because of its superficial similarly to C. dinteri. Some of the more prominent morphological features to differentiate C. omundomba from C. dinteri are compared in Table 1. In the Tree Atlas of Namibia (Curtis & Mannheimer 2005) the distribution range of C. dinteri is mapped as two disjunct regions, namely a core area to the south of latitude 20˚S in central Namibia, and an outlier to the north of latitude 19˚S in the Kaokoveld, up to the Kunene River. However, these northern records in the Kaokoveld refer to the new species, previously misidentified as C. dinteri due to similarities in habit and leaf morphology. There is a gap of ± 200 km in distribution of the two species, with C. omundomba occurring to the north of 19˚S and C. dinteri to the south of 20˚S. Commiphora omundomba can, in addition to C. dinteri, also be confused with C. capensis and C. oblanceolata, with which it shares a similar habit and non-peeling bark, trifoliolate leaves, and perigynous flowers. The three species have, however, different distributions: C. oblanceolata is distributed from just north of the Kunene River Valley in southwestern Angola south to Swakopmund in the central Namib (thus partly overlapping with the range of the new species), whereas C. capensis has a southerly distribution in the Gariep Centre of Endemism (Van Wyk & Smith, 2001) in Namibia and South Africa. In addition to distribution, C. omundomba, differs from these two species in several characters of the exudate, leaves, flowers, and fruit. Commiphora capensis and C. oblanceolata have clear, squirting (when branchlets are damaged) exudate, whereas the exudate in C. omundomba is white and not squirting. The lamina of the terminal leaflets in C. omundomba is oblanceolate or narrowly obovate and the lateral leaflet lamina is oblanceolate, narrowly obovate, obovate, elliptic, oblong, or suborbicular. All leaflets in C. oblanceolata are narrowly oblanceolate to oblanceolate, and in C. capensis they are rotund, obovate or cordate. The flowers in C. omundomba are borne solitary or clustered and usually have three sepals and petals (rarely four) in comparison with the consistently four sepals and petals of C. oblanceolata and C. capensis. The flowers in C. oblanceolata and C. capensis are borne solitary or in simple dichasial cymes. The putamen in C. omundomba and C. oblanceolata has a pseudo-aril, whereas in C. capensis the pseudo-aril is lacking. Hiern (1896) mentions an extremely resinous low shrub with trifoliolate leaves from the Namib Desert in Angola (Welwitsch 1253). An image of this specimen (labelled C. virgata Engler [1894: 139]) has been examined and although sterile, proofed to belong to C. omundomba. In Conspectus Florae Angolensis (Exell & Mendonça 1951) C. omundomba keys out as C. virgata Engler (1894: 139). The latter, however, has papery bark that conspicuously peels transversely (vs. bark not papery nor peeling). Additional specimens examined (paratypes):— ANGOLA. Namibe Province: 37 km from Lucira on road to Dombe Grande, 1312DA, 294 m, 10 May 2015, Swanepoel 345 (LUBA!, PRU!); Mucuio, 1412CC, 21 m, 10 May 2015, Swanepoel 344 (LUBA!, PRU!); 25 km on Bentiaba road from Namibe-Caruculo junction, 1412CD, 414 m, 16 April 2010, Swanepoel 341 (LUBA!, PRU!); 22 km south of Namibe on road to Tombua, 1512CA, 100 m, 9 May 2015, Swanepoel 343 (LUBA!, PRU!); Flamingo River between coast and Namibe-Tombua road, 1512CA, 89 m, 14 May 2016, Swanepoel 346 (LUBA!, PRU!); 5 km north of Curoca River on Iona-Namibe road, 1512CB, 295 m, 8 May 2015, Swanepoel 342 (LUBA!, PRU!); 18 km northwest of Iona on road to Curoca River, 1612CD, 581 m, 27 May 2019, Swanepoel 565, 567 (LUBA!, PRU!); 10 km northeast of Iona on road from Oncocua, 1612DC, 738 m, 27 May 2019, Swanepoel 566 (LUBA!, PRU!); Mossamedes. By the red-sandy rocks at the base of Serra de Montes Negros, 10 August 1859, Welwitsch 1253 (LISU!). — NAMIBIA. Kunene Region: 400 m due south of Kunene River, 2 km east of Wilderness Safari Lodge, 1712AA, 200 m, 21 April 2003, Swanepoel 33, 54 (WIND!); Kunene River Valley opposite Hartmann Mountains, 1712AB, 170 m, 2 May 2017, Swanepoel 348 (WIND!); Between Hartmann Valley and Rooidrom, 1712CB, 850 m, 21 April 2003, Swanepoel 53 (WIND!); Engo Valley near Oranjedrom, 1712CD, 729 m, 3 May 2017, Swanepoel 564 (WIND!); Onjuva, 1712DC, 28 November 2004, Curtis BC2185, BC2181 (WIND!); 40 km NW Orupembe, 1812AA, 18 July 1973, Robinson & Knouwds 63 (WIND!); 32 km NW Orupembe, 1812AB, 24 April 1966, Giess 9402 (WIND!); Orupembe waterhole, 1812BA, 5 May 1957, De Winter & Leistner 5737 (PRE!, WIND!); 13 km nördlich Sarusas, 1812DA, 10 June 1963, Giess & Leippert 7466 (WIND!); Rocky hill slope on plains just north of Purros, 1812DA, 620 m, 27 November 2004, Curtis BC2177, BC2179 (WIND!); 25 km NW of Purros, 1812DA, 500 m, 12 April 1985, Jacobsen & Moss K154 (PRE, WIND!); Purros-Orupembe Road D3707, 1812DA, 584 m, 18 April 2003, Swanepoel 26, 27, 28, 30 (WIND!); Purros-Orupembe Road D3707, 1812DD, 604 m, 18 April 2003, Swanepoel 29 (WIND!)., Published as part of Swanepoel, Wessel, Weeks, Andrea & Van Wyk, Abraham E., 2022, Commiphora omundomba (Burseraceae), a new species from Angola and Namibia, pp. 207-218 in Phytotaxa 543 (4) on pages 211-216, DOI: 10.11646/phytotaxa.543.4.1, http://zenodo.org/record/6479377, {"references":["Gostel, M. R., Phillipson, P. B. & Weeks, A. (2016) Phylogenetic reconstruction of the myrrh genus, Commiphora (Burseraceae), reveals multiple radiations in Madagascar and clarifies infrageneric relationships. Systematic Botany 41: 67 - 81. https: // doi. org / 10.1600 / 036364416 X 690598","Van Wyk, A. E. & Smith, G. F. (2001) Regions of floristic endemism in southern Africa: a review with emphasis on succulents. Umdaus Press, Hatfield, Pretoria, 199 pp.","Curtis, B. A. & Mannheimer, C. A. (2005) Tree atlas of Namibia. National Botanical Research Institute, Windhoek, 674 pp. Also available, with additional photographs and information, from: https: // treeatlas. biodiversity. org. na (accessed 8 August 2021)","Hiern, W. P. (1896) Burseraceae. Catalogue of the African plants collected by Dr. Friedrich Welwitsch in 1853 - 1861 1 (1): 123 - 128. [https: // www. biodiversitylibrary. org / item / 42462 page / 155 / mode / 1 up]","Engler, A. (1894) Plantae Gurichianae. Ein Beitrag zur Kenntnis der Flora von Deutschsudwestafrica. Botanische Jahrbucher fur Systematik, Pflanzengeschichte und Pflanzengeographie 19: 128 - 152. [https: // www. biodiversitylibrary. org / item / 677 page / 134 / mode / 1 up]","Exell, A. & Mendonca, F. (1951) Burseraceae. Conspectus Florae Angolensis 1: 297 - 305. https: // doi. org / 10.2307 / 1216558"]}
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- 2022
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43. Commiphora omundomba (Burseraceae), a new species from Angola and Namibia
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SWANEPOEL, WESSEL, primary, WEEKS, ANDREA, additional, and VAN WYK, ABRAHAM E., additional
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- 2022
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44. The Acacia controversy resulting from minority rule at the Vienna Nomenclature Section: Much more than arcane arguments and complex technicalities
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Moore, Gerry, Smith, Gideon F., Figueiredo, Estrela, Demissew, Sebsebe, Lewis, Gwilym, Schrire, Brian, Rico, Lourdes, van Wyk, Abraham E., Luckow, Melissa, Kiesling, Roberto, and Sousa S., Mario
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- 2011
45. Acacia, the 2011 Nomenclature Section in Melbourne, and beyond
- Author
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Moore, Gerry, Smith, Gideon F., Figueiredo, Estrela, Demissew, Sebsebe, Lewis, Gwilym, Schrire, Brian, Rico, Lourdes, and van Wyk, Abraham E.
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- 2010
46. Documented Utility and Biocultural Value of Aloe L. (Asphodelaceae): A Review
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Grace, Olwen M., Simmonds, Monique S. J., Smith, Gideon F., and van Wyk, Abraham E.
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- 2009
47. The End Justifies the Means
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van Wyk, Abraham E.
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- 2007
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48. (1770) Proposal to Conserve Calvatia nom. cons. (Basidiomycota, Lycoperdaceae) against an Additional Name, Lanopila
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Coetzee, Johan C. and van Wyk, Abraham E.
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- 2007
49. Sectional Classification of Gymnosporia (Celastraceae), with Notes on the Nomenclatural and Taxonomic History of the Genus
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Jordaan, Marie and van Wyk, Abraham E.
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- 2006
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50. Conserving Acacia Mill. with a Conserved Type. What Happened in Vienna?
- Author
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Smith, Gideon F., van Wyk, Abraham E., Luckow, Melissa, and Schrire, Brian
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- 2006
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