<p><strong>Notes on the phytogeography and conservation status of the genus <em>Acanthopsis</em> (Acantheae, Acanthaceae)</strong></p>

Abstract

Acanthopsis is a genus endemic to southern Namibia and southwestern South Africa. Until recently the taxonomy of the group was poorly understood. As a result of a new taxonomic framework (recognising 20 species), the risk of extinction of each taxon could be reassessed and updated. This contribution presents an overview of the distribution and conservation status of the species, as well as the patterns and possible processes involved in the phytogeography of the genus. Specimen localities for all examined specimens were georeferenced and these values were used for mapping and conservation assessments. Phylogenetic relationships within Acanthopsis were studied by using sequence data from the following six gene regions: nrITS, matK, rbcL, rps16, rpl32-trnL and trnS-trnG-trnG. The group appears to have diversified in the arid mountainous semi-desert of the Richtersveld, Northern Cape, South Africa, with the vast majority (96%) of Acanthopsis taxa endemic or near-endemic to the Succulent Karoo Region (more or less congruent with the Succulent Karoo Biome). Twenty of the 23 taxa are range-restricted and have an Extent of Occurrence ≤10000 km2, with at least eight of these known from only one or two subpopulations each. Fourteen (61%) of the taxa are Red Listed as Least Concern, while 39% are Red Listed as Threatened (Vulnerable, Endangered and Critically Endangered)—mainly as a result of habitat loss due to overgrazing and trampling by domestic livestock. Although the distribution ranges of most members of Acanthopsis coincide with protected areas, the effectiveness of conservation in these regions is questionable as some protected areas are prone to overgrazing and trampling by domestic livestock. The lack of phylogenetic resolution, complex taxonomy and the high numbers of range-restricted and habitat-specific species implies recent speciation in Acanthopsis due to topography, ecological gradients and climatic conditions prevailing in the arid northwestern parts of South Africa’s Northern Cape and adjacent arid parts of southern Namibia.

Potential Distribution of Pilocarpus microphyllus in the Amazonia/Cerrado Biomes under Near-Future Climate Change Scenarios

“…The recommendation to create new protected areas (primary forest areas help directly in the expansion of plant species) should be an environmental priority, particularly in the state of Maranhão. Since the jaborandi plant is of socioeconomic importance for many families in north/northeast Brazil (related to the extractive exploitation of non-timber products), it is urgent to implement public policies for conservation and sustainable management, as suggested worldwide, from researchers in different continents, for other threatened plant species [86][87][88], together with the creation of ex situ conservation programs to protect the genetic diversity (germosplam bank) of populations of this endangered species.…”

A taxonomic revision of Acanthaceae tribe Barlerieae in Angola and Namibia. Part 2

“…(Munday 1983(Munday , 1995Darbyshire et al 2020a), Petalidium (Tripp et al 2017) and, in the border region of southern Namibia and the Northern Cape of South Africa, Acanthopsis Harv. (Steyn et al 2019). Angola and Namibia are also home to two endemic genera of Acanthaceae, Dinteracanthus Schinz and Mcdadea E.Tripp & I.Darbysh., both within the tribe Ruellieae (Tripp & Darbyshire 2017, 2020).…”

Notes on morphological characteristics and life history strategy of the genus Acanthopsis Harv. (Acanthaceae)

“…The Succulent Karoo Biome is particularly rich in Acanthopsis diversity, with 21 of the 23 taxa occurring here. This biome is associated with the presence of low winter rainfall and extreme summer aridity (along the coast and west-facing Great Escarpment, the rainfall is supplemented by coastal fog) (Steyn et al 2019).…”

“…The biogeography and conservation status of members of Acanthopsis, as well as the taxonomic importance of the indumentum, were dealt with by Steyn et al (2019) and Steyn and Van Wyk (2021) respectively. The aim of this paper is to give an overview of some noteworthy, albeit often casual or anecdotal, observations made on the morphological characteristics and life history strategy during the taxonomic study that may help explain the biology of the genus in relation to the prevailing habitat conditions.…”