ABSTRACT
To support the work of the Global Conservation Consortium for Erica and update the Erica checklist in the World Flora Online (WFO), we have curated the taxonomic backbone in the WFO by expanding it to include updated nomenclatural information from the International Plant Name Index, missing names present in the World Checklist of Vascular Plants (WCVP), the Botanical Database of Southern Africa (BODATSA), and from the "International register of heather names" database, a data source not readily available online. The result is the most robust database of Erica names to date, including 851 species, 111 subspecies, 244 varieties, and 2787 synonyms, which is a reliable reference for initiatives such as the Erica identification aid, conservation prioritisation, and gap analyses. We disambiguate common orthographic variants within the database and present an overview of these. We also comment on the correct orthography of E.heleophila Guthrie & Bolus and E.michellensis Dulfer and the validity of E.tegetiformis E.G.H.Oliv. are discussed, and the use of E.adunca Benth. for a South African species rather than E.triceps Link, which is here regarded as insufficiently known and of uncertain application, is clarified.
ABSTRACT
The KwaZulu-Natal province of South Africa has a varied topography, geology and climate and presents diverse habitats that support a rich and diverse flora. Aloes are well represented in KwaZulu-Natal, with four genera [Aloe L., Aloiampelos Klopper & Gideon F.Sm., Aloidendron (A.Berger) Klopper & Gideon F.Sm. and Aristaloe Boatwr. & J.C.Manning] and 49 taxa occurring in the province. Fourteen of these are endemic and eleven near-endemic to the province. A floristic treatment of the aloes of KwaZulu-Natal is presented in the form of a synoptic review. Included are an identification key to the aloes that occur naturally in the province, species-level distribution maps and accompanying images, so providing for the first time, an atlas of aloe occurrence in this part of the subcontinent.
ABSTRACT
BACKGROUND: Aloe vera supports a substantial global trade yet its wild origins, and explanations for its popularity over 500 related Aloe species in one of the world's largest succulent groups, have remained uncertain. We developed an explicit phylogenetic framework to explore links between the rich traditions of medicinal use and leaf succulence in aloes. RESULTS: The phylogenetic hypothesis clarifies the origins of Aloe vera to the Arabian Peninsula at the northernmost limits of the range for aloes. The genus Aloe originated in southern Africa ~16 million years ago and underwent two major radiations driven by different speciation processes, giving rise to the extraordinary diversity known today. Large, succulent leaves typical of medicinal aloes arose during the most recent diversification ~10 million years ago and are strongly correlated to the phylogeny and to the likelihood of a species being used for medicine. A significant, albeit weak, phylogenetic signal is evident in the medicinal uses of aloes, suggesting that the properties for which they are valued do not occur randomly across the branches of the phylogenetic tree. CONCLUSIONS: Phylogenetic investigation of plant use and leaf succulence among aloes has yielded new explanations for the extraordinary market dominance of Aloe vera. The industry preference for Aloe vera appears to be due to its proximity to important historic trade routes, and early introduction to trade and cultivation. Well-developed succulent leaf mesophyll tissue, an adaptive feature that likely contributed to the ecological success of the genus Aloe, is the main predictor for medicinal use among Aloe species, whereas evolutionary loss of succulence tends to be associated with losses of medicinal use. Phylogenetic analyses of plant use offer potential to understand patterns in the value of global plant diversity.
