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Great efforts have been done to collect germplasm of the Arachis genus in South America, however, many regions still remain underexplored. Under the hypothesis that these regions have new and diverse populations/species of Arachis, several expeditions were carried out since 2000 in Bolivia, to increase the documentation of the genus diversity. As a first result of these explorations, a new species of section Arachis with B genome is formally described. Arachis inflata is closely related to A. magna and A. ipaënsis, but it can be clearly distinguished from them, and from any other species of the genus, for having a type of fruit with a completely distinct morphology. The fruit has a smooth epicarp, but shows a bullated aspect, due to the presence of air chambers in the mesocarp.

The Gran Chaco is a wide ecologic-geographic region comprising northern Argentina, western Paraguay, southern Bolivia and the southwestern extreme of Brazil. This region exhibits extreme temperatures, annually regular frosts, and sedimentary soils; it has been dramatically threatened by agriculture expansion in recent decades. Therefore, increasing knowledge of plant diversity is critical for conservation purposes. We present a Legume checklist of the Gran Chaco ecoregion including conservation status of its endemic species. Leguminosae is the third most diverse plant family in the Neotropics. Assuming a rigorous spatial definition of the Gran Chaco, we recorded 98 genera, 362 species, and 404 specific and infraspecific taxa. Endemic/typical taxa were 17%, comparable to adjacent tropical plant formations, and they were found in higher percentages in Caesalpinioideae (24%) and Cercidoideae (33%) than Papilionoideae (11%) subfamily. We also analyzed the plant diversity comparing lineages and subregions. The Gran Chaco Legumes are predominantly widespread generalists, or they belong to either Chaco sensu stricto or Neotropical Seasonally Dry Tropical Forest (SDTF) lineages. Though the Humid Chaco registered the highest species richness, Dry Chaco and Sierra Chaco, the most threatrened subregions, exhibited the highest percentages of exclusive and proper Chaco-lineage species. These results suggest that diversification of Legumes has been most relevant in Dry Chaco and Sierra Chaco, probably by their more demanding and harsh environmental conditions limiting the dispersion of generalists or intrusive-invading species. This study is paramount to reach an improved delimitation of the Gran Chaco ecoregion in transitional areas with the SDTF and Cerrado formations. Conservation status is critical in genera of high economic interest, such as Arachis, Mimosa and Prosopis. At least one third of endemic taxa exhibit a critical status of conservation or are endangered, many of them being relevant to inbreeding program or exhibiting multiple economic uses. Fil: Morales, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina Fil: Oakley, Luis Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. International Union for Conservation of Nature; Reino Unido Fil: Sartori, Ángela L. B.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Mogni, Virginia Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina Fil: Atahuachi, Margoth. Universidad Mayor de San Simón; Bolivia Fil: Vanni, Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Fortunato, Renée Hersilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina Fil: Prado, Darien Eros. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina

10. Mimosa castanoclada Barneby & Fortunato Chaco of NW Paraguay and Andean foothills of southern Bolivia along the upper Pilcomayo in Tarija; closely allied to M. farinosa and M. detinens, two other Chaco species.

51. Mimosa velloziana Mart., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 219, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

60. * Mimosa aff. weddelliana Benth Although J. R. I. Wood et al. 26528 (Santa Cruz, Chiquitos, Desvio Yacuces 3km hacia Valle Hermoso, 19.0021 S, 58.1442 W, 156 m, zona de bosque chaque��o, lugares pantanosos inundados, LPB, K, USZ) is in some respects (armed shrub, appressed short scaberulous bulbous setae, striate ovate-acuminate stipules which are glabrous on faces, parallel-nerved leaflets, moriform capitula in bud, spathulate floral bracts) a good match for M. weddelliana, it differs in having longer setae, wider stipules, 8���9 pinnae pairs (versus 1 pair), fewer veins on leaflets, sparser corolla indumentum, corolla lobes 3-nerved, and recurved as opposed to straight aculei and shows some similarities to M. brachycarpa, M. scaberrima and M. cisparanensis. The differences in number of pinnae pairs are especially striking. Further collections are needed to evaluate this potentially unusual plant., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 221, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

46. ** Mimosa suberosa Atahuachi & C. E. Hughes Described based on a handful of collections all from the last decade and all from the southern Serranía de Huanchaca in very open fire-prone cerrado with low shrubs scattered in rough grassland. Guillén et al. 4157 (K!, LPB, USZ!); Mostacedo 1766 (MO, NY, USZ!); T. J. Killeen et al. 7459 (MO, USZ!); J. R. I. Wood et al. 16560 (holotype K!; isotypes HSB, LPB). It is locally abundant in the area around Campamento Huanchaca 2 and is one of three Serranía de Huanchaca endemics along with M. huanchacae and M. rastrera. When originally described, M. suberosa was thought to be endemic to Bolivia, but it has recently been collected also from the SE flanks of the Serranía de Huanchaca (L. Borges 782 UB, pers. comm.), where known as the Serra do Ricardo Franco in Brazil. See Atahuachi and Hughes (2006).

Mimosa chiquitaniensis Atahuachi & C.E. Hughes, sp. nov. (Fig. 2) Similar to M. pudica Linnaeus (1753: 518), but consistently unarmed rather than armed with a pair of aculei shortly below all nodes, with strictly globose as opposed to ellipsoid capitula, strictly 1-jugate rather than 2-jugate leaves, and longer (4.5–6 cm compared to 1–3 cm) peduncles. Type:— BOLIVIA. Santa Cruz: Chiquitos, vicinity of Santiago de Chiquitos, on roadsides and in disturbed Cerrado on sandy soils, 18°20´03´´ S 59°35´22´´ W, 600 m, 24 October 2007, fl, J.R.I. Wood et al. 23707 (holotype LPB!; isotypes FHO!, K!, USZ). Functionally herbaceous, unarmed, perennial herb with several humifuse, 20–40 cm-long stems arising from a stout, woody root or short caudex, the capitula held on ± erect peduncles in axils of coevally developing leaves on actively growing shoots, and rising amongst and above foliage, the stems, leaf stalks and peduncles densely pilose and short white puberulent, with slender horizontally spreading or weakly downwardly pointing 2 (–3) mm long setae. Stipules persistent, narrow or triangular lanceolate, 7 × 1.3 mm, variably (0–) 3–4 (–5)-nerved, and densely setulose on margins, the setae slender to 2 mm. Leaves sensitive, bipinnate, consistently 1-jugate, the leaf stalks 2.5–3.5 cm long ending in a slender spicule, the pinnae 3–4.5 cm, with a pair of minute narrowly lanceolate paraphyllidia to 2 mm, and (12–) 13–15 (–17) pairs of leaflets per pinna, these linear, acute at apex, 7 (–12) × 1.3 (–3.5) mm, glabrous above, densely but unevenly pilose, with 2–3 mm-long appressed trichomes below, only the strongly asymmetric midrib prominulous below, secondary veins barely visible. Flowers in globose capitula, often singly or occasionally in pairs in leaf axils held on slender 4.5–6.5 cm-long peduncles, cone-like, the narrow linear or subulate, apically setulose, 2 mm long bracts exserted in bud; calyx minute, a diminutive campanulate, incipiently pappiform somewhat asymmetric ring to 0.4 mm; corolla 4-merous, the petals 2–2.5 × 0.5 mm, 1-nerved, the lobes densely puberulent; 8-androus, the pink filaments exserted 6–7 mm beyond the corolla. Fruits in dense clusters of 12–15 per capitulum, linear-oblong, asymmetrically acute at apex, round at base, 10–15 × 3–4 (–5) mm, (3–) 4-seeded, the valves and replum pilose with slender 1 mm setae, readily breaking up into one-seeded articles to leave a persistent replum, this splitting at the apex after the articles are shed. Distribution and Ecology: — Mimosa chiquitaniensis is known only from the type locality where it grows in disturbed, grazed and periodically burned scrubby cerrado on sandy soils at the edge of the village of Santiago de Chiquitos amongst grasses with Mimosa nuda Bentham (1841: 362), Eriosema crinitum (Kunth 1823: 421–422) Don (1832: 348), Indigofera asperifolia Bong. ex Bentham (1839: 431), Tephrosia adunca Bentham (1839: 432), and scattered trees of Dimorphandra gardneriana Tulasne (1844:185) and Stryphnodendron obovatum Bentham (1875: 374). Additional specimens examined: — BOLIVIA. Santa Cruz: Chiquitos, just below the town of Santiago de Chiquitos on trail to La Cueva, 642 m, 18°20´39´´ S, 59°35´31´´ W, 30 December 2002, (fl), J.R.I. Wood et al. 18818 (FHO!, K!, LPB, USZ). Santa Cruz: Chiquitos, at the edge of the town of Santiago de Chiquitos on trail to La Cueva and El Arco, 600 m, 18°21´S, 59°36´W, 23 February 2006, (fl), J.R.I. Wood et al. 22258 (FHO!, K!, LPB, USZ). Etymology: —Nowhere else in Bolivia is the density of species of Mimosa greater than in the Serranía de Santiago in Chiquitos Province in the Department of Santa Cruz, and this is especially true of the area around the village of Santiago de Chiquitos where M. chiquitaniensis is locally endemic. Phenology: —Flowering from October to January in the southern hemisphere summer, mainly after fire. Conservation status: — Mimosa chiquitaniensis is known only from the type locality where a single population covering ca. 2 ha and including ca. 400 individuals is found on the edge of the small town of Santiago de Chiquitos in an area that is clearly threatened as the town expands and new houses are constructed. Indeed the majority of the species population is on plots already demarcated and fenced for such use. For these reasons, the species was categorised as Critically Endangered (CR) by Mamani et al. (2010) under criteria B2 ab (iii) within the IUCN system. No further populations have been found and the future of this species would seem extremely precarious. Notes: — Mimosa chiquitaniensis fits morphologically, ecologically and geographically within either subseries Pedunculosae or subseries Pudicae of ser. Mimosa, sect. Mimosa, and keys out to subseries Pedunculosae in Barneby’s (1991) key. However, placement in neither of these subseries is borne out by phylogenetic analysis of trnD -trnT sequences of two accessions of M. chiquitaniensis (one of which— J.R.I. Wood 23707 —was included, as Mimosa sp., in the study of Simon et al. 2011), which are not placed with other members of subseries Pedunculosae (Clade U in Simon et al. (2011)), or subseries Pudicae (Clades P and S) (Fig. 1). Instead, M. chiquitaniensis, whilst clearly a member of sect. Mimosa ser. Mimosa, forms an isolated lineage within that section, outwith Clades P, U, or S recognized by Simon et al. (2011) (Fig. 1), adding weight to delimitation of M. chiquitaniensis as a new species. Despite the uncertain phylogenetic placement of M. chiquitaniensis and the non-monophyly of subseries Pudicae (split between Clades P and S), we have assigned this species to subseries Pudicae, pending realization of a new infrageneric classification of Mimosa. Barneby (1991) was well aware of the morphological heterogeneity and potential non-monophyly of subseries Pudicae, recognizing two subgroups, one around M. pudica and M. polydactyla Humb. & Bonpland ex Willdenow (1806: 1033), and the other allied to M. verecunda Bentham (1841: 368) and M. xanthocentra Martius (1838: 50), and this is borne out by the molecular phylogeny of Simon et al. (2011) with placement of these two groups in their Clades P and S. Mimosa chiquitaniensis resembles M. pudica in habit, but may be distinguished from that species in being consistently unarmed (M. pudica is usually armed with a pair of aculei shortly below all nodes), by the globose as opposed to ellipsoid capitula, strictly 1-jugate as opposed to generally 2-jugate leaves, and 4.5–6.5 cm, as opposed to 1–3 (–3.5) cm-long peduncles. From M. xanthocentra, M. chiquitaniensis can be distinguished by 3–4.5 cm as opposed to 6–12 cm long pinnae, 13–15 versus 30–82 pairs of leaflets per pinna, and 4.5–6.5 cm versus 5–20 mm long peduncles. Amongst the ten species of subseries Pedunculosae which occur in similar campo habitats on hills of the Paraná and Paraguay basins in southern Paraguay and adjacent Brazil and Argentina, M. chiquitaniensis most closely resembles M. pedunculosa Micheli (1883: 55), and to lesser degrees M. brevipetiolata Burkart (1948: 176) and M. alleniana Morong (1893: 98). From M. pedunculosa it differs in larger 7 mm as opposed to 2–3 mm long stipules, a dense indumentum of spreading setae compared to the essentially glabrous M. pedunculosa, pinnae 3–4.5 cm as opposed to 1–2.5 cm, 1- as opposed to 3–4-veined leaflets and shorter peduncles. From M. brevipetiolata it differs in the spreading as opposed to appressed setae, 25–35 mm as opposed to 10–15 mm petioles, moriform as opposed to cone-like capitula and lack of visible secondary leaflet venation. Finally, from M. alleniana, M. chiquitaniensis differs most notably in leaflet venation with just the midrib visible below, as opposed to (2–) 3-nerved from the pulvinule and with coarsely V-shaped secondary veins within the margin in M. alleniana.

39. Mimosa revoluta (Kunth) Benth. A widespread and common mid-elevation species in seasonally dry tropical forest of the Andean valleys of Bolivia and Peru., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 218, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

40. Mimosa rufescens Benth. var. rufescens A macrophyllidious liana, widespread in the Amazon basin., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 218, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

34. * Mimosa piresii Barneby Known to Barneby (1991) only from Amazonian Brazil. Now from a single collection in Bolivia: Dept. Beni, Prov. Itenez, Serrania San Simon, Rio Colorado, Arroyo Guizzely, 13��32��S, 62��02��W, Murillo 58 (K!)., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 218, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835."]}

9. Mimosa candollei R. Grether Considered as M. quadrivalvis var. leptocarpa by Barneby (1991), but segregated as a distinct species by Grether (2000). None of the other infraspecific taxa assigned to M. quadrivalvis by Barneby (1991) occur in Bolivia. Mimosa candollei is a widespread and weedy ruderal along roadsides and in abandoned pastures across much of seasonally dry South America., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 212, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835.","Grether, R. (2000) Nomenclatural changes in the genus Mimosa (Fabaceae, Mimosoideae) in southern Mexico and Central America. Novon 10: 29 - 37. http: // dx. doi. org / 10.2307 / 3393180"]}

21. Mimosa dolens Vellozo subsp. acerba (Benth.) Barneby var. acerba A widespread species, but known from Bolivia by very few collections scattered in disturbed sub-humid forests of the Andean dry valleys (e.g. J.R.I. Wood et al. 20319 from Samaipata, Santa Cruz, LPB, K, USZ)., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 215, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

20. Mimosa diplotricha C. Wright ex Sauvalle var. diplotricha A formidably prickly, prolific and fast-growing weed of secondary and ruderal vegetation, widespread throughout the Neotropics., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 214, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

49. * Mimosa tobatiensis Barneby & Fortunato Known to Barneby (1991) from only two collections from nearby localities ca. 25° S in Paraguay, but several collections from Nuflo de Chávez, 10 km W of Quimome, Chiquitos, Santa Cruz (F. Mamami & Saucedo 676 K!, J. R. I. Wood et al. 25770 K!, F. Mamani & Jardim 393 K! (this last collection previously mis-identified as the closely related M. adenocarpa Benth.) and J. R. I. Wood et al. 27759, K) are a good match for Barneby’s description. See also M. orthocarpa.

7. Mimosa boliviana Benth Main distribution restricted to Bolivia between 1000���3000 m on the eastern flanks of the Andes in Chuqisaca, Cochabamba and La Paz, but also extending into southern Peru in Puno (Sandia) and the upper Urubamba valley, Cuzco., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 212, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

28. �� Mimosa lepidota Herzog A setose-podded variant of M. lepidota from Tarija could potentially merit recognition as a new variety of this species, pending better sampling from southern Bolivia., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 216, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

31. Mimosa orbignyana Barneby This species has remained poorly understood, known only from the type collection (d��Orbigny 743 P, Bolivia, Chiquitos, August 1831), and apparently never re-collected since, until very recently. It was described by Barneby (1991) as ���in unknown habitat, but to be sought in campo or cerrado at or above 700 m on the Sierra de Santiago, near 18�� 30��S in south-east Santa Cruz, Bolivia�� and has been considered endemic to Bolivia. Within the last two years, two collections, both from further north, on the Serran��a Huanchaca have been made (J.R.I. Wood 26772, LPB, K, USZ, from the southwest part of the meseta of the Serran��a Huanchaca in the Noel Kempf National Park in Bolivia, and L. Borges 787, UB, from the southern end of the Huanchaca range in neighbouring Mato Grosso in Brazil, where the range is known as the Serra do Ricardo Franco). However, despite extensive fieldwork in areas where d���Orbigny is likely to have visited in ���Chiquitos���, no material matching this species has been re-collected from any of these areas. This is perhaps surprising, given that M. orbignyana forms a substantial shrub to 2 m height, multi-stemmed from the base, resprouting after fire from an underground woody root system that is much thicker than the above-ground stems, and with conspicuous 1���1.2 m tall efoliate pseudoracemes of bright pink flowers (Figs. 6 & 7). Barneby (1991) placed M. orbignyana in his ser. Setosae of sect. Habbasia and indicated likely affinities to M. riedelii Benth. from the Chapada dos Guimar���es in Mato Grosso and M. aguapeia Barneby from the Serra do Aguapei also in Mato Grosso. These overall affinities are confirmed by analysis of a trnD -trnT sequence of M. orbignyana as sister to a clade comprising ser. Setosae and ser. Pachycarpae (clade O in Simon et al. (2011)) plus M. corynadenia (Fig. 1). Although no sequence data are available yet for M. riedelii and M. aguapeia, the discovery of M. orbignyana in the Serran��a Huanchaca confirms Barneby���s notion that these three potentially closely allied species occupy disjunct ranges on these ancient sandstone chapadas around the periphery of the upper Rio Paraguay basin., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 216, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835.","Dahmer, N., Simon, M. F., Schifino-Wittmann, M. T., Hughes, C. E., Miotto, S. T. S. & Giuliani, J. C. (2011) Chromosome numbers in the genus Mimosa L.: cytotaxonomic and evolutionary implications. Plant Systematics & Evolution 291: 211 - 220. http: // dx. doi. org / 10.1007 / s 00606 - 010 - 0382 - 2"]}

8. Mimosa camporum Benth A weedy monocarpic herbaceous species, widely distributed in northern S America and C America, which according to Barneby (1991) reaches its southern limit in the far north of Bolivia (Beni)., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 212, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835."]}

15. ** § Mimosa craspedisetosa Fortunato & Palese Described in 1999 based on incomplete material (fruiting only, the flowers at that time unknown). J.R.I. Wood et al. 22858 (LPB, K, USZ) is apparently the first flowering collection and confirms placement in ser. Leiocarpae of sect. Batocaulon as proposed by Fortunato & Palese (1999).This placement is further supported by its robustly supported inclusion in Clade N of the molecular phylogeny of Simon et al. (2011), which includes ser. Leiocarpae pro parte. This species is now recorded from four localities in eastern Bolivia: Cerro San Miguel, the type locality; Quimome, old rd to El Tinto (J.R.I. Wood et al. 22858, LPB, K, USZ ); 60km E of Roboré (J.R.I. Wood et al. 24488; J.R.I. Wood & Pozo 26084; J.R.I. Wood 27127, LPB, K, USZ) and Taperas (J.R.I. Wood et al. 27874, LPB, K, USZ). This suggests that this species is perhaps restricted to Cerrado Chaqueño (Abayoy) habitats rather than being restricted to Chaco woodland as originally described. Although M. craspedisetosa is still, as far as known, endemic to eastern Bolivia, it appears to be spreading along the line of the road from Santa Cruz to Brazil (Wood 2011), the population at Taperas being found for the first time in 2013 in an area visited frequently in earlier years.

54. ** �� Mimosa woodii Atahuachi & C. E. Hughes Globally rare but locally frequent in seasonally dry tropical forest of two tributaries of the Rio Cotacajes at two nearby localities in Depts. Cochabamba and La Paz. See Atahuachi and Hughes (2006)., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 219, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Atahuachi, M. & Hughes, C. E. (2006) Two new species of Mimosa (Fabaceae) endemic to Bolivia. Brittonia 58: 59 - 65. http: // dx. doi. org / 10.1663 / 0007 - 196 X (2006) 58 [59: TNSOMF] 2.0. CO; 2"]}

32. * Mimosa orthocarpa Spruce ex Benth The occurrence of Mimosa orthocarpa in Bolivia represents a surprisingly large range extension for a species previously unrecorded from south of the Amazon and known to Barneby (1991) from the Amazon, northern South America and parts of Central America. Several collections (J.R.I. Wood et al. 22861, LPB, K, USZ, J.R.I. Wood & D. Soto 27134, LPB, K, USZ and D. Villarroel et al. 2046, USZ) from two disjunct localities in Bolivia���ca. 50 km S of Concepcion (Las Trancas and El Encanto), and Cerro Mut��n, German Busch���can be attributed here. Mimosa orthocarpa is characteristic of granite rock platforms, particularly in the Lomerio area, a habitat also mentioned by Barneby (1991) in his notes on this species from northern South America. The species is morphologically close to and easily confused with M. tobatiensis Barneby & Fortunato, another species here newly documented for Bolivia (see below). These two species, distinguished by details of leaflet venation, indumentum, and pod shape (M. orthocarpa with larger, more robust and almost linear pods cf. the slightly falcate chartaceous pods of M. tobatiensis) and previously considered to be remotely allopatric putative sister species (Barneby 1991), are thus now known to co-occur in Bolivia., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 216, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835."]}

4. �� Mimosa auriculata Benth A very distinctive species with large glaucous foliaceous striate stipules and dilated paraphyllidia. Endemic to the rocky slopes and rupestral habitats of the Serran��as Chiquitanas where it is locally abundant at Chochis and Santiago de Chiquitos. The type is from Santiago de Chiquitos, where it has been collected frequently in recent years, as well as further west on Cerro Pel��n, near Chochis (J.R.I. Wood 16473, LPB, K)., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 212, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

Mimosa rastrera Atahuachi & C.E. Hughes, sp. nov. (Figs. 4 & 5) M. rastrera is closely allied to ser. Neptunioideae and ser. Auriculatae, but can be clearly distinguished from the four species of ser. Neptunioideae by lack of interpinnal spicules and presence of a pair of suborbicular to ovate paraphyllidia resembling diminutive leaflets, and from M. auriculata, the only member of ser. Auriculatae, by its prostrate as opposed to erect woody shrub habit, multijugate as opposed to 1-jugate leaves, and much smaller leaflets. Type:— BOLIVIA. Santa Cruz: Velasco, Parque Nacional Noel Kempff Mercado, on trail from Camp. Huanchaca 2 to ‘la Piscina’, meseta de Caparuch, midway beyond stream, 729 m, 14°30´36´´ S, 60°44´58´´ W, 14 May 2010, (fl, fr), J.R.I. Wood et al. 26736 (holotype K!; isotypes LPB, UB, USZ!). Unarmed procumbent or diffuse, almost prostrate, functionally herbaceous subshrub, arising from an extensive xylopodium, branching from the base, the slender pliant stems trailing 40–60 cm in length, shoots angled, tinged reddish maroon, the whole plant more or less glabrous apart from a few very scattered short white hairs, capitula 1 (–2) at nodes on short slender un-branched efoliate panicles weakly exserted 5–7 cm beyond the foliage, or in axils of leaves. Stipules persistent, weakly foliaceous, deltate triangular, cordate at base, 3.5 × 1.8–2 mm, glabrous, striately venulose, with 12–15 longitudinal, prominent and somewhat anastomosing nerves on dorsal side. Leaves bipinnate, the whole leaf up to 6 cm long, leaf stalks including petiole to 4 cm long, deeply grooved and ending in a short pointed mucro to 1.5 mm, the petiole 1.3 cm long, with 3–4 pairs of pinnae, the interpinnal segments 8–9 mm; pinnae with 7–10 pairs of leaflets and a pair of suborbicular to ovate paraphyllidia inserted immediately above the pulvinules, these like diminutive leaflets, to 0.5 mm long, the pinna rachis 2–2.5 cm, the interfoliar segments 1.2–1.8 mm; larger leaflets 5.5 × 1.3 mm, linear, rounded at apex, asymmetric at base, glabrous throughout, venation prominent on lower leaflet surfaces, 3–4 primary veins from base, the midrib almost central, 5–6 (–8) pairs of almost perpendicular secondary veins. Flowers clustered in globose capitula to 5 mm diameter prior to anthesis, these on slender, glabrous, striate 1.2 cm long erect peduncles, the flowers sessile and subtended by linear-lanceolate, 2.8 × 0.5 mm glabrous bracts, striate with 6–7 longitudinal ribs, the bracts exserted and the capitula cone-like in bud; calyx campanulate to 1 mm including shallowly truncate blunt lobes; corolla 4-merous, the petals 1-nerved and 2.5 × 1 mm, the corolla lobes to 1.2 mm; 8- androus, diplostemonous, filaments pale whitish to striking bright pink; ovary linear-oblong, densely hairy to 1.2 mm. Fruits (few seen) one per capitulum, short stipitate, linear-oblong, apex long-acuminate, base acute, strongly planocompressed, markedly constricted between seeds such that almost lomentiform, 20–25 × 4.5–5 mm, the pods breaking up into one-seeded articles to leave a persistent replum, the replum prominent, 0.4 mm wide, whole pod glabrous, the valves pale yellow-brown, chartaceous, colliculate over seeds; seeds 2–3 per pod. Distribution and Ecology: — Mimosa rastrera is known only from a handful of localities in the Serranía Huanchaca in the Noel Kempff National Park and the adjacent Serra de Ricardo Franco in Brazil. It occurs locally in sandy places in the very extensive open dry stony campo limpo that dominates this vast meseta, interspersed with rock outcrops on ridges and streams lined with adjacent campo húmedo and sometimes gallery forest. Additional specimens examined: — BOLIVIA. Santa Cruz: Velasco, Parque Nacional Noel Kempff Mercado, Las Gamas, sobre rocas areniscas, 900 m, 14° 49´S, 60° 23´W, 27 March 1993, (fl buds), T.J. Killeen et al. 4805 (MO, USZ). BRAZIL. Mato Grosso, Vila Bela da Santissima Trinidade, Fazenda Pelicano, caminho para a serra de Ricardo Franco, próxima ao rio Paraíso, 560 m, 14° 51´S, 60° 14´W, 20 March 2014, M.F. Simon et al. 2128 (UB). Etymology: —The species epithet derives from the Spanish ‘ rastrera ’ meaning creeping or low in reference to the prostrate habit of this plant. Phenology: —Flowering in April and May. Conservation Status: — Mimosa rastrera is currently known from three localities all of them on the Serrranía de Huanchaca in the Noel Kempff National Park in Bolivia and the adjacent Serra de Ricardo Franco in Brazil, and must therefore be considered globally rare pending further exploration and collections. However, the Noel Kempff National Park remains largely inaccessible and under-collected botanically and this species is probably more widespread on the Meseta de Caparuch, at least in the southern part. It may well be inconspicuous except amongst new growth following burning. Notes: —Ovate to suborbicular paraphyllidia that simulate diminutive leaflets, as found in M. rastrera, are restricted within sect. Batocaulon to ser. Stipellares and the monotypic ser. Auriculatae (Barneby 1991). Previously these two series were thought to be closely allied (Bentham 1875; Barneby 1991), but recent molecular phylogenetic analysis of Mimosa including representatives of both series shows that this is not so (Simon et al. 2011). This tell-tale character of dilated paraphyllidia along with lack of interpinnal spicules together suggest placement of M. rastrera 210 • Phytotaxa 260 (3) © 2016 Magnolia Press ATAHUACHI ET AL. in ser. Stipellares. An alternative would be placement of M. rastrera in ser. Auriculatae, or ser. Neptunioideae, which together form a group (Clade M in Simon et al. 2011) characterized by striately 12–50-nerved stipules, which are also found in M. rastrera, but which are generally lacking in ser. Stipellares. Phylogenetic analysis of a trnD-trnT sequence from M. rastrera alongside data from Simon et al. (2011) provides robust support (PP=1.0) for placement of M. rastrera within the striate-stipuled clade that includes ser. Neptunioideae and Auriculatae (Fig. 1). Based on this analysis, and pending a new infrageneric classification, we assign M. rastrera to ser. Neptunioideae of sect. Habbasia. Placement here implies that dilated paraphyllidia are independently derived in ser. Stipellares and within clade M in M. rastrera and M. auriculata Bentham (1875: 430), both of which also lack interpinnal spicules which are a feature of ser. Neptunioideae. Independent derivations of these traits perhaps come as no surprise given the high levels of morphological homoplasy in Mimosa more generally (Simon et al. 2011). Within Clade M of Simon et al. (2011), M. rastrera is readily distinguished from all four members of ser. Neptunioideae by lack of interpinnal spicules and presence of a pair of suborbicular to ovate paraphyllidia resembling diminutive leaflets, and from M. auriculata, the only member of ser. Auriculatae, which is an erect woody shrub and has a radically different leaf formula with a single pair of pinnae and much larger leaflets than M. rastrera.

50. Mimosa tweediana Barneby ex Glazier & Mackinder, Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 219, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

29. Mimosa neptunioides Harms Gregarious and locally abundant in several parts of Santa Cruz., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 216, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

36. * Mimosa polycephala Benth. var. taxifolia Barneby Not recorded from Bolivia by Barneby (1991), but now known from several collections (T. J. Killeen et al 7449 (K) a 1.8 m shrub from the Noel Kempff National Park, Campamento ���Laja���, on path from Geobol, 15 km SE of Los Fierros in semideciduous forest at 14��33��58���� S, 60��46��22���� W, 400 m, also J. R. I. Wood 26795 and 26822, LPB, K, USZ, from the same area) from the dry forests on the flanks of the southern end of the Serran��a Huanchaca, where it is locally common., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 218, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175, {"references":["Barneby, R. C. (1991) Sensitivae Censitae: a description of the genus Mimosa L. (Mimosaceae) in the New World. Memoirs of the New York Botanical Garden 65: 1 - 835."]}

2. Mimosa albida Humboldt & Bonpland ex Willd. var. albida The main distribution of M. albida lies in Mexico, C. America and NW South America with only a handful of outlier records from Bolivia (from Yungas and Santa Cruz), and it is doubtfully native here (Barneby 1991).

45. Mimosa somnians Humb. & Bonpl. ex Willd. subsp. somnians var. somnians subsp. viscida (Willd.) Barneby var. velascoensis (Harms) Barneby. Wood 27420, K, LPB, USZ . subsp. viscida (Willd.) Barneby var. viscida. Wood et al. 26568, K, LPB, USZ., Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 219, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

47. Mimosa tarda Barneby, Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 219, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

35. Mimosa polycarpa Kunth. var subandina Barneby, Published as part of Margoth Atahuachi, M. Leontien Van Der Bent, John R. I. Wood, Gwilym P. Lewis & Colin E. Hughes, 2016, Bolivian Mimosa (Leguminosae, Mimosoideae): three new species and a species checklist, pp. 201-222 in Phytotaxa 260 (3) on page 218, DOI: 10.11646/phytotaxa.260.3.1, http://zenodo.org/record/192175

Three new species of Mimosa (Leguminosae, Mimosoideae) M. chiquitaniensis, M. chochisensis and M. rastrera, two of them endemic to Bolivia, and the third also occurring in Brazil, are described and an annotated species checklist for the genus in Bolivia is presented. This brings the tally of species of Mimosa recorded from Bolivia to 55 (plus five doubtful species to be confirmed), an increase of ca. 50% since the monographic account of the genus published just over 25 years ago.

Two new species of Mimosa are described: M. woodii (sect. Mimosa), from the central Andean valleys of Bolivia, and M. suberosa (sect. Habbasia), from Serranía Huanchaca in the Noel Kempff National Park in the north east of Santa Cruz Department in eastern Bolivia. The affinities of each are discussed, their distributions mapped, and both species are illustrated. © 2006, by The New York Botanical Garden Press.