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Issue: Vol. 626 No. 3: 23 Nov. 2023
Type: Article
Published: 2023-11-23
DOI: 10.11646/phytotaxa.626.3.1
Page range: 145-158
Abstract views: 241
PDF downloaded: 109

A new species of Sesamothamnus (Pedaliaceae) from Namibia and Angola

Independent Researcher; P.O. Box 21168; Windhoek; Namibia; H.G.W.J. Schweickerdt Herbarium; Department of Plant and Soil Sciences; University of Pretoria; Pretoria; 0002 South Africa
H.G.W.J. Schweickerdt Herbarium; Department of Plant and Soil Sciences; University of Pretoria; Pretoria; 0002 South Africa; South African National Biodiversity Institute; Private Bag X101; Pretoria; 0001 South Africa
Eudicots endemism flora Iona National Park Kaokoveld Centre of Endemism Kunene Region Sesamothamneae sphingophily taxonomy

Abstract

Sesamothamnus leistneri is formally described as a new species with a restricted range, only known from the mountains along the Kunene River in the Kaokoveld Centre of Endemism, a biogeographical region that spans southwestern Angola and northwestern Namibia. The designations “S. leistner(i)anus” or “S. leistneri” have been previously used to refer to this species, but they were not validly published until now. These trees grow in rocky places on mountain slopes, in kloofs (gorges) and on plateaus. Diagnostic characters for S. leistneri include the pronounced tree habit with thickset semi-succulent stem and branches, relatively large green leaves, the corolla lacking a spur, and flowers with a white to cream-white corolla limb. A comparison of some of the more prominent morphological features to differentiate between S. leistneri and its possibly closest relative, S. rivae, as well as the other four species, S. benguellensis, S. guerichii, S. lugardii, and S. busseanus are provided. Based on IUCN Red List categories and criteria, a conservation assessment of Least Concern (LC) is recommended for S. leistneri.

 

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