Search

Darbyshire, Iain, Burrows, John E., Luke, Quentin, Langa, Clayton (2022): Cladoceras rovumense sp. nov. (Gentianales-Rubiaceae), a new species from southeast Tanzania and northeast Mozambique. European Journal of Taxonomy 833: 46-59, DOI: https://doi.org/10.5852/ejt.2022.833.1883, URL: http://dx.doi.org/10.5852/ejt.2022.833.1883

Celosia patentiloba C.C.Towns. Hooker’s Icones Plantarum 38: 41, t. 3732 (Townsend 1975); Flora of Tropical East Africa: 13 (Townsend 1985). Type TANZANIA • Newala; alt. 670 m [2200 ft]; 9 Apr. 1959; W. Hay 61; holotype: K (2 sheets). Additional collection studied MOZAMBIQUE • Cabo Delgado Prov., Mueda District; 11°31.822ʹ S, 39°26.504ʹ E; alt. 947 m; 10 Sept. 2009; A. Banze 106; K, LMA. Distribution and habitat Restricted to the Rovuma CoE, known from the Maconde Plateau of Southeast Tanzania and the Mueda Plateau of northeast Mozambique. It occurs in partial or full shade in woodland including in degraded or disturbed areas, at ca 670–950 m a.s.l. elevation. Conservation status This species is currently assessed on the IUCN Red List as Critically Endangered – CR B2ab(iii) – and possibly extinct (Howard et al. 2020). Whilst the new record from the Mueda Plateau adds a second location, this species could be considered to be severely fragmented given that the two known subpopulations are over 65 km apart, whilst the dispersal potential of this species is likely to be very limited given that it is a small understorey herb. Recolonisation between these isolated subpopulations is, therefore, unlikely to occur. Further, there is very little intact wild habitats still present on both the Maconde and Mueda Plateaux which are highly degraded, with much conversion to agricultural land. At Mueda Plateau, for example, there has been an estimated loss of dense woodland and dry forest vegetation cover of over 96% (Timberlake et al. 2011). Whilst this species appears tolerant of some disturbance, it is unlikely to persist in farmlands. Furthermore, as noted by Howard et al. (2020), it is possible that the Maconde subpopulation is no longer extant. Therefore, the assessment of CR B2ab(iii) is upheld here. Taxonomic notes Two collections from the Rondo Plateau in southeast Tanzania (G.P. Clarke 35; Q. Luke 12958; both K) are closely allied to this species but have markedly smaller perianth segments. These collections may represent a further species of Rovuma CoE endemic in Celosia or possibly a distinct variant of C. patentiloba. Further material is desirable to fully assess the extent of this variation., Published as part of Darbyshire, Iain, Burrows, John E., Luke, Quentin & Langa, Clayton, 2022, Cladoceras rovumense sp. nov. (Gentianales-Rubiaceae), a new species from southeast Tanzania and northeast Mozambique, pp. 46-59 in European Journal of Taxonomy 833 on pages 54-55, DOI: 10.5852/ejt.2022.833.1883, http://zenodo.org/record/6949886, {"references":["Townsend C. C. 1975. Celosia patentiloba. Hooker's Icones Plantarum 38: 41, t. 3732.","Townsend C. C. 1985. Amaranthaceae. In: Polhill R. M. (ed.) Flora of Tropical East Africa. Balkema, Rotterdam.","Howard G., Kamau P., Kindeketa W., Luke W. R. Q., Lyaruu H. V. M., Malombe I., Maunder M., Mwachala G., Njau E. - F., Peres Q., Schatz G. E., Siro Masinde P., Ssegawa P., Wabuyele E. & Wilkins V. L. 2020. Celosia patentiloba. The IUCN Red List of Threatened Species 2020: e. T 157997 A 756253. https: // doi. org / 10.2305 / IUCN. UK. 2020 - 2. RLTS. T 157997 A 756253. en","Timberlake J., Goyder D., Crawford F., Burrows J. E., Clarke G. P., Luke Q., Matimele H., Muller T., Pascal O., De Sousa C. & Alves T. 2011. Coastal dry forests in northern Mozambique. Plant Ecology and Evolution 144: 126 - 137. https: // doi. org / 10.5091 / plecevo. 2011.539"]}

Cladoceras rovumense I.Darbysh., J.E.Burrows & Q.Luke sp. nov. urn:lsid:ipni.org:names:77302733-1 Figs 1–3 Tarenna sp. 53 sensu Degreef, Opera Botanica Belgica 14: 143 (Degreef 2006); Timberlake et al., Plant Ecology and Evolution 144: 131 (Timberlake et al. 2011); Burrows et al., Trees and Shrubs Mozambique (Burrows et al. 2018); Darbyshire et al., Plant Ecology and Evolution 153: 441 (Darbyshire et al. 2020). Diagnosis Cladoceras rovumense sp. nov. resembles C. subcapitatum in floral and fruit morphology, but differs most markedly in (a) being a free-standing tree or shrub, lacking modified spinose lateral branches (vs a scandent shrub with some lateral branches modified to form ± recurved spines to aid climbing in C. subcapitatum); (b) the leaves being obovate or obovate-elliptic, larger, up to 17.5 × 10.5 cm, with surfaces pubescent particularly on the veins beneath and midrib above, becoming scabridulous at maturity (vs leaves elliptic to oblong-oblanceolate, smaller, up to 12 × 4.8 cm, glabrous); (c) the inflorescences being borne on leafless lateral branches (vs inflorescence-bearing branches with one or more pairs of leaves at least in flower, sometimes caducous at fruiting); (d) the inflorescence being dense, capitate and with 20+ flowers (vs less dense and usually with clear branching, 9–15-flowered); (e) the calyx lobes being rounded to broadly and convexly triangular, with an irregular, sometimes toothed margin (vs calyx lobes acute-triangular to -lanceolate); and (f) the style and stigma together measuring 17–19 mm long (vs 8–10 mm long in C. subcapitatum); see Table 1. Etymology The epithet denotes that this species is endemic to the proposed Rovuma CoE in coastal southern Tanzania and northern Mozambique. Type MOZAMBIQUE • Cabo Delgado Prov., Quiterajo, Pt. 463; 11.7676° S, 40.3743° E; alt. 115 m; 24 Nov. 2009; Q. Luke 13883; holotype: K [K000787442]; isotypes: EA, LMA, MO, P. Paratypes MOZAMBIQUE • Cabo Delgado Prov., Mueda Plateau; 11°20ʹ S, 39°26ʹ E; alt. 760 m; 14 Dec. 2003; [W.R.] Q. Luke, O. Kibure & E. Nacamo 10116; EA, K, LMA, MO, UPS • Cabo Delgado Prov., Namacubi Forest (the Banana), west of Quiterajo; 11°45ʹ55ʺ S, 40°23ʹ45ʺ E; alt. 90 m; 25 Nov. 2008; J.E. & S.M. Burrows 10748; BNRH, K, LMA. TANZANIA • Lindi Region, Rondo Plateau, Rondo Forest Reserve; 10°07ʹ S, 39°13ʹ E; alt. 750 m; 6 Feb. 1991; S. Bidgood, R. Abdallah & K. Vollesen 1357; K (2 sheets), NHT. Description Small, slender deciduous tree or shrub 1.5–7 m tall; young stems ± quadrangular, with papery maroonbrown bark that readily exfoliates in strips or patches, at first puberulous with ± patent hairs to 0.35 mm long but soon glabrescent. Stipules soon caducous, triangular, 3.7–7.5 mm long, with a thickened blackish-brown central portion and with paler, somewhat hyaline margins but these often infolded in dry material, glabrous externally, with long pale hairs internally. Leaves clustered towards ends of main and widely divergent lateral branches, ± immature at flowering, subsessile or on puberulent petiole to 7 mm long; blade of mature leaves obovate or obovate-elliptic, 9–17.5 × 5.8–10.5 cm (l/w ratio 1.55–1.9: 1), base cuneate to somewhat attenuate or some leaves abruptly obtuse at base, apex shortly acuminate or (sub)attenuate, lateral veins 7–11 per side, these and the midrib prominent and often pale beneath, surfaces pubescent with hairs densest and longest on veins beneath and midrib above, conspicuous when young, becoming more sparsely hairy with maturity, the blade then scabridulous; minute pocketdomatia present in axils of lateral veins beneath but inconspicuous. Inflorescences terminating leafless lateral branches 11–28.5 cm long, flowers 20 or more, sessile, crowded in capitate corymbs with highly reduced and thickened branches; bracts subtending the main inflorescence branches maroon at least at apex, triangular with a slender apiculum, 3.2–4.5 × 3–4 mm, those subtending the flower clusters smaller, 1–2.5 mm long. Calyx tube (hypanthium) 1.9–2.7 mm long; calyx lobes pink- to maroon-tinged, rounded to broadly and convexly triangular, ± 1 mm long, with an irregular, sometimes toothed margin, glabrous or margins sparsely ciliate. Corolla white except for yellowish-green tube and central portion of lobes externally, glabrous externally; tube narrowly cylindrical, (30–)38–42 × 1.5–2 mm, pilose with long wispy hairs internally mainly in distal half; lobes oblong-elliptic, 5–9 × 3.7–4.2 mm. Stamens with anthers subsessile, held at corolla mouth, 2.6–3 mm long. Ovary bilocular, placentae affixed centrally on septum; style and stigma together 17–19 mm long, glabrous, stigma ± linear, included within corolla tube. Fruit pale green, globose-obovoid, 6–8 mm in diameter, endocarp thin, glabrous, calyx persistent, usually 6–8 seeds per fruit (as few as 2 seeds per fruit reported by Degreef 2006); seeds orange-brown, 4–5 mm in diameter, hemispheric with a slightly angular lower side and a deep circular hilar excavation ca 1.5 mm in diameter, testa smooth and glossy. Distribution and habitat Restricted to the proposed Rovuma CoE, known from the Rondo Plateau of Southeast Tanzania and the Mueda Plateau and Namacubi Forest (Quiterajo) in northeast Mozambique (Fig. 3). Occurs in deciduous and semi-evergreen coastal and lowland dry forest and thicket on sandy soils, including areas of secondary woodland/thicket, at 90–760 m altitude. At Quiterajo, it was recorded from Guibourtia schliebenii (Harms) J.Léonard dominated dry forest with species of Memecylon L., Warneckea Gilg and Strynchnos L. common in the understorey (J. E. & S.M. Burrows 10748). The type specimen from the same site was found growing in close proximity to a number of rare and globally threatened species, i.e., Xylopia tenuipetala D.M.Johnson & Goyder (Q. Luke 13884), Vismianthus punctatus Mildbr. (Q. Luke 13885), Vismia pauciflora Milne-Redh. (Q. Luke 13886 A) and Warneckea cordiformis R.D.Stone (Q. Luke 13887). On the Rondo Plateau, it was noted from within forest of Milicia excelsa (Welw.) C.C.Berg, Dialium L., Albizia Durazz., and Pteleopsis Engl. (= Terminalia L. according to some authorities). Conservation status This species is known from three locations and has an extent of occurrence of 6601 km 2 and a calculated area of occupancy of 16 km 2. At Mueda Plateau, there has been an estimated loss of dense woodland and dry forest vegetation cover of over 96%, whilst in the Rio Messalo-Quiterajo area this figure is 71.2% (Timberlake et al. 2011). On the Rondo Plateau in Tanzania, 2755 ha of natural forest were cleared during the Rondo Forest Programme in 1952–1978 and replaced by commercial plantation of exotic tree species. Some clearance of natural forest for subsistence agriculture and for fuelwood collection is an ongoing threat at this site (Clarke 2001). However, a sizeable area of forest remains on the western slopes of the plateau, some of which has regenerated since the cessation of forestry. The gazetting of this site as a Nature Forest Reserve in 2016 may hopefully result in increased protection for the biodiversity there (Wabuyele et al. 2020). With only three locations and a continuing decline in the extent and quality of habitat at the majority of these sites, this species is provisionally assessed as Endangered – EN B 2ab(iii)., Published as part of Darbyshire, Iain, Burrows, John E., Luke, Quentin & Langa, Clayton, 2022, Cladoceras rovumense sp. nov. (Gentianales-Rubiaceae), a new species from southeast Tanzania and northeast Mozambique, pp. 46-59 in European Journal of Taxonomy 833 on pages 50-54, DOI: 10.5852/ejt.2022.833.1883, http://zenodo.org/record/6949886, {"references":["Degreef J. 2006. Revision of continental African Tarenna (Rubiaceae-Pavetteae). Opera Botanica Belgica 14: 1 - 150.","Timberlake J., Goyder D., Crawford F., Burrows J. E., Clarke G. P., Luke Q., Matimele H., Muller T., Pascal O., De Sousa C. & Alves T. 2011. Coastal dry forests in northern Mozambique. Plant Ecology and Evolution 144: 126 - 137. https: // doi. org / 10.5091 / plecevo. 2011.539","Burrows J., Burrows S., Lotter M. & Schmidt E. 2018. Trees and Shrubs Mozambique. Publishing Print Matters, Noordhoek, Cape Town.","Darbyshire I., Goyder D., Wood J., Banze A. & Burrows J. 2020. Further new species and records from the coastal dry forests and woodlands of the Rovuma Centre of Endemism. Plant Ecology and Evolution 153: 427 - 445. https: // doi. org / 10.5091 / plecevo. 2020.1727","Clarke G. P. 2001. The Lindi local centre of endemism in SE Tanzania. Systematics and Geography of Plants 71: 1063 - 1072. https: // doi. org / 10.2307 / 3668738","Wabuyele E., Sitoni D., Njau E. - F., Mboya E. I., Lyaruu H. V. M., Kindeketa W., Kalema J., Kabuye C., Kamau P., Luke W. R. Q., Malombe I., Mollel N., Schatz G. E. & Ssegawa P. 2020. Hugonia grandiflora. The IUCN Red List of Threatened Species 2020: e. T 158188 A 765731. https: // doi. org / 10.2305 / IUCN. UK. 2020 - 2. RLTS. T 158188 A 765731. en"]}

Eucomis sonnetteana N.R.Crouch, Mart.-Azorín & J.E.Burrows sp. nov. differs from E. zambesiaca Baker in its extremely short peduncle, shorter and fewer-flowered raceme, shorter leaves, and its unpleasant rather than sweet floral scent.