A new species of Osteospermum subgen. Tripteris (Asteraceae: Calenduleae) from the Namib Desert, Namibia

WESSEL SWANEPOEL; VERA DE CAUWER; ABRAHAM E. VAN WYK

doi:10.11646/phytotaxa.487.3.1

Issue: Vol. 487 No. 3: 26 February 2021

Type: Article

Published: 2021-02-26

DOI: 10.11646/phytotaxa.487.3.1

Page range: 185–194

Abstract views: 44

PDF downloaded: 51

**A new species of Osteospermum subgen. Tripteris (Asteraceae: Calenduleae) from the Namib Desert, Namibia**

WESSEL SWANEPOEL⁺⁻
VERA DE CAUWER⁺⁻
ABRAHAM E. VAN WYK⁺⁻

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.

Biodiversity Research Centre, Faculty of Natural Resources and Spatial Sciences, Namibia University of Science and Technology, Private Bag 13388, Windhoek, Namibia.

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.

endemism flora Kaokoveld Centre of Endemism Osteospermum sect. Trifenestratae sand armour succulent taxonomy Tripteris Eudicots

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Abstract

Osteospermum namibense, here described as a new species, is known only from the northern part of the Namib Desert in the Kaokoveld Centre of Endemism, northwestern Namibia. Within a broad generic concept for Osteospermum (tribe Calenduleae), the new species is a member of subgen. Tripteris. These dwarf shrubs grow on rocky outcrops under harsh desert conditions. Diagnostic characters for Osteospermum namibense include the perennial, woody habit, di- or trichotomous branching, succulent leaves arranged in rosettes, and capitula with 12–14 rays. A comparison of some of the more prominent morphological features to differentiate between O. namibense and its possible nearest relative, O. microcarpum (=Tripteris microcarpa), is provided. Based on IUCN Red List categories and criteria, a conservation assessment of Vulnerable (VU D1) is recommended for the new species.