A revision of Hoodia and Lavrania (Asclepiadaceae-Stapelieae)

Hoodia Sweet ex Decne is revised to contain 13 species which are divided into 2 sections. Sect. Hoodia contains H.currorii, H.dregei, H.gordonii, H.juttae and H.parviflora. Sect. Trichocaulon contains H.alstonii, H.flava, H.mossamedensis, H.officinalis, H.pedicellata, H.pilifera, H.ruschii and H.triebneri, all except H.ruschii formerly constituting the section "Eutrichocaulon", the so-called "spiny" species of Trichocaulon. The remainder of Trichocaulon, the section Cactoidea, is transferred to Lavrania Plowes. This genus then consists of the monotypic section Lavrania (L.haagnerae) and Sect. Cactoidea containing L.cactiformis, L.marlothii, L.perlata and L.picta

Huernia humpatana (Apocynaceae) a new species from southern Angola

A new species, Huernia humpatana Bruyns (Apocynaceae–Ceropegieae), closely related to H. similis N.E.Br., is described from the Chela Mountains of Huila Province in southern Angola. The two species are distinguished by the 5-angled and erect stems with more prominent tubercles up to 6 mm long joined into clear angles and separated by V-shaped grooves in H. humpatana as opposed to very obtusely 4-angled stems with tubercles only 2 mm long and only indistinct grooves between the angles in H. similis. Furthermore, in H. similis the nodding corolla is ± 9 mm in diameter with sepals ± 2 mm long, while in H. humpatana the horizontally facing corolla is 18–20 mm in diameter with sepals 4–6 mm long

A revised classification of the Apocynaceae s.l.

The Asclepiadaceae, as traditionally defined, have repeatedly been shown to be an apomorphic derivative of the Apocynaceae. It has often been recommended that the Asclepiadaceae be subsumed within the Apocynaceae in order to make the latter monophyletic. To date, however, no comprehensive, unified classification has been established. Here we provide a unified classification for the Apocynaceae, which consists of 424 genera distributed among five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. Keys to the subfamilies and tribes are provided, with lists of genera that (as far as we have been able to ascertain) are recognized in each trib

A molecular phylogeny and classification of the largely succulent and mainly African Euphorbia subg. Athymalus (Euphorbiaceae)

Euphorbia subg. Athymalus consists of approximately 150 species and is one of the four main lineages that comprise the species–rich genus Euphorbia. Most species in the subgenus are stem succulents with greatly reduced leaves, but there are also leafy herbs, shrubs, trees and geophytes. The subgenus is restricted to arid regions of the Old World. Most species are found in sub–Saharan Africa, with one in Macaronesia and adjacent parts of western Africa, a few in the Arabian Peninsula (one of which extends into Iran) and one native to Madagascar. Twenty–three species are endemic to the northeastern Horn of Africa (SE Ethiopia, Socotra, Somalia), while 72 species are restricted to southern Africa (including Botswana, Lesotho, Namibia, South Africa and Swaziland). Sixty of those are endemic to South Africa alone, where they are particularly associated with the semi–arid west and south of the country in the Greater Cape Floristic Region and the Nama Karoo Region. We sampled 88 species and analyzed data from the nuclear ribosomal ITS and plastid ndhF regions. Analyses of the separate and combined datasets produced phylogenies that confirm the monophyly of E. subg. Athymalus and the placement of E. antso from Madagascar as sister to the rest of the subgenus. Our analyses also show that the subgenus consists of a grade of early–diverging lineages that are relatively poor in species and that the major radiation of succulent species in southern Africa forms a highly supported clade (E. sect. Anthacanthae). Species–level relationships within this southern African clade, however, remain largely unresolved. Our phylogenetic hypotheses allow us to propose a new classification for E. subg. Athymalus where seven sections are recognized, two of which are newly described. The large southern African E. sect. Anthacanthae is further divided into five subsections, and four series are recognized in E. subsect. Florispinae.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147157/1/tax6269.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147157/2/tax6269-sup-001-pdf.pd

A worldwide molecular phylogeny and classification of the leafy spurges, Euphorbia subgenus Esula (Euphorbiaceae)

The leafy spurges, Euphorbia subg. Esula, make up one of four main lineages in Euphorbia. The subgenus comprises about 480 species, most of which are annual or perennial herbs, but with a small number of dendroid shrubs and nearly leafless, pencilâ stemmed succulents as well. The subgenus constitutes the primary northern temperate radiation in Euphorbia. While the subgenus is most diverse from central Asia to the Mediterranean region, members of the group also occur in Africa, in the Indoâ Pacific region, and in the New World. We have assembled the largest worldwide sampling of the group to date (273 spp.), representing most of the taxonomic and geographic breadth of the subgenus. We performed phylogenetic analyses of sequence data from the nuclear ribosomal ITS and plastid ndhF regions. Our individual and combined analyses produced wellâ resolved phylogenies that confirm many of the previously recognized clades and also establish a number of novel groupings and placements of previously enigmatic species. Euphorbia subg. Esula has a clear Eurasian center of diversity, and we provide evidence for four independent arrivals to the New World and three separate colonizations of tropical and southern Africa. One of the latter groups further extends to Madagascar and New Zealand, and to more isolated islands such as Réunion and Samoa. Our results confirm that the dendroid shrub and stemâ succulent growth forms are derived conditions in E. subg. Esula. Stemâ succulents arose twice in the subgenus and dendroid shrubs three times. Based on the molecular phylogeny, we propose a new classification for E. subg. Esula that recognizes 21 sections (four of them newly described and two elevated from subsectional rank), and we place over 95% of the accepted species in the subgenus into this new classification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146962/1/tax6221.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146962/2/tax6221-sup-004-pdf.pd