A -E Barleria lancifolia. A -C habit and flowers, dark-throated form; D habit and flowers, pale-throated form; E trailing form from NW Namibia with semi-succulent leaves. F Barleria alata, habit and flowers, cut specimen. G -H Barleria grootbergensis. G habit; H inflorescences. A, C collected as Tripp & Dexter 781; E as Tripp et al. 4798; G, H as Tripp & Dexter 828. A -E, G, H Namibia, F Angola. PHOTOS: A, C, E, G, H E. A. MANZITTO-TRIPP; B, D I. DARBYSHIRE; F B. DITSCH.

A -E Barleria lancifolia. A -C habit and flowers, dark-throated form; D habit and flowers, pale-throated form; E trailing form from NW Namibia with semi-succulent leaves. F Barleria alata, habit and flowers, cut specimen. G -H Barleria grootbergensis. G habit; H inflorescences. A, C collected as Tripp & Dexter 781; E as Tripp et al. 4798; G, H as Tripp & Dexter 828. A -E, G, H Namibia, F Angola. PHOTOS: A, C, E, G, H E. A. MANZITTO-TRIPP; B, D I. DARBYSHIRE; F B. DITSCH.

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The second part of a taxonomic revision of the tribe Barlerieae (Acanthaceae) in Angola and Namibia covers Barleria sects. Somalia and Stellatohirta . Thirty-one taxa including 27 accepted species are treated. Four new species ( Barleria eburnea , B. imatensis , B. louiseana and B. thunbergiiflora ), one new subspecies ( B. kacondensis subsp. glabr...

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Context 1
... ± 31 mm long; anthers 3.3 -4.3 (-4.8) mm long; lateral staminodes to 1.5 mm long, flattened and triangular. Ovary densely glandularand eglandular-puberulous distally; style glabrous; stigma 1.5 -3 mm long, curved. Capsule 2-seeded, 14 -18 mm long including beak 5 -7 mm long, glandularand eglandular-puberulous; seeds 5.7 -6.2 × 5.4 -5.8 mm. Fig. 6G ...
Context 2
... 2-seeded, 14 -17.5 mm long, eglandular-and glandular-puberulous mainly on beak or sometimes with only antrorse-eglandular hairs; seeds ± 6.5 × 5 mm. Fig 6A - ...
Context 3
... form from northern Namibia, associated with mopane woodland and areas of exposed calcrete (e.g. Giess 15179, WIND!; Tripp et al. 4798, COLO!, K!) is distinctive in having prostrate or sometimes weakly scrambling stems and more succulent leaves than typical (E. A. Manzitto-Tripp, pers. obs.; Fig. 6E) -it is otherwise similar to other pale-throated forms from northern Namibia. This form is known from few collections, mainly from the Tsumeb-Grootfontein area of Oshikoto but also around Opuwo in Kunene. It warrants further investigation. 47. Barleria gossweileri S. Moore (1911: 305;1930 Subshrub, 30 -150 cm tall; mature stems densely ...

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... The high rate of localised endemics facing land-use intensification, however, indicates a substantial threat to at least some of the geoxyle species, such as Barleria kacondensis subsp. glabrescens which is classified as EN B1ab(iii), i.e., "Endangered, with extent of occurrence < 100 km² and further decline" (Darbyshire et al. 2021) and Bolusia ervoides which has been described as a "rare species and is known from only few collections" (van Wyk et al. 2010). ...
Article
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The Angolan Planalto and adjacent areas are characterised by flammable grassy ecosystems. Within these old-growth grasslands, geoxyles are a dominant component and play a key role in the functioning, diversity and beauty of these ecosystems. Geoxyles are a plant life form characterised by having low aboveground biomass and massive belowground wooden structures from which they can draw stored reserves and resprout quickly after disturbances such as fire. The Angolan Planalto has a high number of geoxyle taxa of which many are endemic to the area. We give an overview of the number of geoxyle taxa in these highlands based on a compilation of all available data, discuss reasons for this remarkable diversity, and point out research and conservation priorities for this important life form that is threatened by upcoming land-use changes.
... nov. of Goyder et al. (2018) has since been described as B. thunbergiiflora I.Darbysh. (Darbyshire et al. 2021) in a revision of Barleria in Angola and Namibia. ...
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Four new species are described from central and eastern Angola and adjacent NW Zambia. All occur in Kalahari sand savannas rich in endemic and more widely distributed geoxylic suffrutices. Despite being known from very few collections, the conservation status of one of these new species is assessed as Least Concern, as these grasslands are nutrient-poor, are in remote sparsely populated areas, and are not threatened with conversion to agriculture. The remaining three are treated as Data Deficient. In addition, one new combination is provided for Ancylanthos rubiginosus Desf. under Vangueria as V. rubiginosa (Desf.) Lantz is an illegitimate later homonym. We also make orthographic corrections to specific epithets commemorating Ilse von Nolde, a collector who made important collections from Quela in Malange in the 1930s.
... Since then, at least 33 additional endemic plant species have been described for the Kaokoveld, many of them in mountainous areas (Swanepoel, 2005(Swanepoel, , 2006a(Swanepoel, , 2006b(Swanepoel, , 2007a(Swanepoel, , 2007b(Swanepoel, , 2008a(Swanepoel, , 2008b(Swanepoel, , 2009a(Swanepoel, , 2009b(Swanepoel, , 2013(Swanepoel, , 2015(Swanepoel, , 2019(Swanepoel, , 2020Van Jaarsveld andSwanepoel, 2007, 2012;Swanepoel and Kolberg, 2011;Tripp and Dexter, 2012;Swanepoel et al., 2015Swanepoel et al., , 2021aSwanepoel et al., , 2021bKolberg and van Slageren, 2016;Darbyshire et al., 2019Darbyshire et al., , 2021Van Jaarsveld, 2019, 2020;Tripp and Darbyshire, 2020;Swanepoel and Manzitto-Tripp, 2022). Few quantitative vegetation surveys have been performed in the Namibian Kaokoveld with widely spread sample plots that are mainly located in the lowlands (Burke, 2005;Becker and Müller, 2007;Jürgens et al., 2018;Hamutenya, 2021). ...
Article
The Kaokoveld Centre of Endemism is a hotspot of biodiversity and endemism, largely underexplored while new species are continually described. A reconnaissance survey of flora and vegetation was undertaken on three remote mountain tops of the western Great Escarpment: Cafema and Tchamalindi in Angola’s Iona National Park, and Middelberg in the Otjihipa Range of Namibia, providing the first floristic account for Serra Cafema. Vegetation cover and woody vegetation structure were assessed, and botanic surveys were performed. Previously collected occurrence data allowed to determine Kaokoveld endemics. Commiphora woodlands were found on the mountains despite the semi-desert on the surrounding plains. Woodlands were interspersed with montane savanna and on Cafema with sclerophyll dwarf shrubs. Our study provides the first assessments of species richness in the Ovahimba Highlands with the highest for Serra Cafema: 56 species per 1000 m2 compared to 47 species per 1000 m2 for the other mountains. Species composition, especially Cafema, is very different from the surrounding lowlands, making a case for a satellite population of Afromontane vegetation. The distribution of sixteen species was expanded from Namibia to Angola. Of the 285 taxa, 12% were Kaokoveld endemics, of which 65% woody species, both relatively high compared to Afromontane vegetation in Eastern Africa. Only a fraction of the flora could be recorded and more surveys after good rainfall are required, especially considering the threats of climate change and overgrazing. The mountain flora deserves priority conservation efforts to protect endemic plants and old taxa that survived in these refuge sites. You can download the full article at: https://www.tandfonline.com/eprint/KCFIEID3IXSXGDEKNK7I/full?target=10.1080/0035919X.2023.2211040
... The checklist of Figueiredo and Smith (2008) was used as the baseline for assessing Angolan species records. Species missing there but subsequently reported in later publications (Swanepoel 2009;Bergh and Nordenstam 2010;De Sousa et al. 2010;Catarino et al. 2013;Abreu et al. 2014;Hind and Goyder 2014;Paton 2014;Cheek et al 2015;Darbyshire 2015;Abrahamczyk et al. 2016;Darbyshire et al 2018;Harris and Wortley 2018a, 2018b, 2018cDarbyshire and Goyder 2019;Swanepoel 2019;Tripp and Darbyshire 2020;Lautenschläger et al. 2020b;Darbyshire et al. 2021;Smith and Lautenschläger 2021;Swanepoel et al. 2021, Figueiredo andSmith 2022) were excluded. ...
Article
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Angola is a tropical country with many biogeographical units and, therefore, has a high floristic diversity. Although an increasing number of floristic studies has been carried out in Angola in recent years, the country is still considered to be underinvestigated as many species being collected were previously unknown there. Several scientific groups working in different parts of Angola contributed to this paper their data from biodiversity assessments. With this we can add 67 species newly recorded for Angola, including two new generic records and five alien species, to the almost 7,300 vascular plant taxa known so far for Angola. Most of the new records for Angola are also present in different neighbouring countries, but they are little known, and their IUCN threat status has not been assessed yet. However, ongoing fieldwork and exploration are needed to complete the floristic knowledge of the understudied country.
... Recent studies (e.g., Linder, 2001;Darbyshire et al., 2019Darbyshire et al., , 2021Frazão et al., 2020;Catarino et al., 2021a) revealed important centers of endemism located in Angola, mainly associated with the Angolan Escarpment Zone in Huíla and the Kaokoveld Desert in Namibe, harboring many endemic and range-restricted species. However, 180-200 naturalized species were also identified and some of them are highly invasive, posing a major threat to native biodiversity (Rejmánek et al., 2017;Goyder and Gonçalves, 2019;Figueiredo and Smith, 2022). ...
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Angola has a great diversity of species and ecosystems and a high level of endemism. However, knowledge of the native flora remains very incomplete and outdated. Leguminosae is the largest family in the country, including many species which are of local or more regional economic importance. Based on an extensive review of bibliographic sources, natural history collections, and online databases, the checklist of Angolan Leguminosae plants was updated, including data on their native distribution, conservation status, and principal uses. The endemic taxa were the subject of additional investigation, including the main habitat, the number of collections preserved in herbaria, and the locality of the first collection. We identified 953 Leguminosae taxa occurring in Angola, of which 165 are endemic to the country. Among the 180 genera found, Crotalaria (136) and Indigofera (96) have the highest number of taxa. Almost half of the studied species have important applications, mainly in traditional medicine (385), forage (267), timber (188), and food (120). Nevertheless, only 27.7% have been assessed according to the IUCN Red List and 10 species are classified as threatened. Thirty-three endemics are known only from the type specimen, revealing the lack of knowledge on these species and the need for further field research. More than 30 type specimens were collected in the Serra da Chela, which highlights the importance of this region for biodiversity conservation.
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Two new species of Barleria subg. Barleria (Acanthaceae) are described from the Soutpansberg Centre of Plant Endemism in Limpopo Province of South Africa: Barleria soutpansbergensis and B. spinosissima . The habitat requirements, conservation status and taxonomic affinities of each species are discussed. Barleria soutpansbergensis is considered to be closely allied to the widespread and frequently cultivated southern African species B. obtusa , whilst B. spinosissima is morphologically most similar to B. bremekampii which has a restricted distribution in northern South Africa and Zimbabwe. Remarkably, the two new species are postulated to occasionally hybridise within the Soutpansberg. Both species are currently assessed as of Least Concern despite their restricted ranges. Barleria spinosissima is noted to be amongst the most densely spiny species of Barleria and, indeed, is a contender as one of the spiniest species of plant in South Africa.
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Recent molecular phylogenetic results have demonstrated that Monechma s.l., a group of plants with ecological importance in the savanna and succulent biomes of sub-Saharan Africa, is polyphyletic with two discrete lineages recognisable. In the present work, we recognise Monechma Groups I and II at the generic rank, which can be distinguished by differences in inflorescence characteristics and seed morphology. The nomenclatural implications of these findings are investigated. The lectotype of Monechma , M. bracteatum Hochst., is a part of a small lineage of plants closely allied to Justicia L. sect. Harnieria (Solms) Benth. for which the earliest valid name is found to be Meiosperma Raf. Hence, Monechma is synonymised within Meiosperma , which comprises six accepted species and two undescribed taxa. The majority of species of former Monechma s.l. are resolved within the second lineage for which the only validly published generic name is Pogonospermum Hochst. This resurrected genus comprises 34 accepted species plus two undescribed taxa. Pogonospermum displays considerable morphological variation and is here subdivided into six sections based primarily on differences in plant habit, inflorescence form, calyx, bract and bracteole venation, and seed indumentum. The new combinations and new sections are validated, and seven accepted species names are lectotypified.
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The genus Saxicolella Engl. (Podostemaceae) are African rheophytes, restricted to rapids and waterfalls as are all members of the family. Previously, Saxicolella sensu lato was shown to be polyphyletic with two separate clades in the molecular phylogenetic study of Koi et al. (2012). The name Pohliella Engl. was recently resurrected for one clade that is sister to the American genera Ceratolacis (Tul.)Wedd., Podostemum Michx. and all Old World Podostemoideae (podostemoids) (Cheek 2020). Pohliella has distichous phyllotaxy, bilocular ovaries, filiform roots with paired holdfasts, and rootcaps. The second clade, Saxicolella sensu stricto, including the type of the generic name, has spiral phyllotaxy, unilocular ovaries, ribbon-like or crustose roots that lack both holdfasts and rootcaps. Saxicolella sensu stricto, sampled from the type species, S. nana Engl. of Cameroon, is embedded within and near the base of the major clade of African podostemoids and is sister to all other African genera apart from Inversodicraea R.E.Fr. and Monandriella Engl. Recently reduced to three species in Cameroon and S.E. Nigeria by the resurrection of Pohliella (3 to 4 species in Ghana and Nigeria and Cameroon), Saxicolella sensu stricto is expanded to eight species in this monograph by description of five new taxa. Saxicolella futa Cheek and S. deniseae Cheek are newly described from Guinea, S. ijim Cheek from Cameroon, the informally named S. sp. A from Gabon, and S. angola Cheek from Angola. The known geographic range of the genus is thus expanded c. 2,500 km westwards to Guinea from eastern Nigeria and c.1,500 km southeastwards from Cameroon to Cuanza do Sul, Angola. The greatest concentration of species occurs in the Cross Sanaga interval of western Cameroon and eastern Nigeria, with three species. Cameroon (3 species) followed by Nigeria and Guinea (2 species each) are the countries with highest species diversity. The genus can be expected to be found in Sierra Leone, Liberia, Ivory Coast and Congo Republic. A classification is proposed grouping the species into three subgenera (Saxicolella, Butumia (G.Taylor) Cheek comb. et. stat. nov. and Kinkonia Cheek subgen. nov.) based on root morphology and shoot position and morphology. The discovery, morphology, circumscription, distribution, and ecology of Saxicolella is reviewed, an identification key to the species is presented, together with descriptions, synonymy, links to illustrations, and extinction risk assessments for each of the eight species now recognised. All of the species are provisionally assessed as either Endangered or Critically Endangered using the IUCN 2012 standard, making this genus among the most threatened of its size globally. The major threats, above all, are hydro-electric projects. Saxicolella deniseae may already be globally extinct, and two of the four known locations of S. angola appear lost, S. sp. A of Gabon is threatened at at least one of its three locations, while Saxicolella futa is threatened at all three locations, all due to incipient or active hydro electric projects. Contamination of watercourses by increased turbidity from silt-load due anthropic changes and by eutrophication from pollution are also threats for the majority of the species.