Taxonomic revision of Ceropegia sect. Huernia (Asclepiadoideae, Apocynaceae) in Saudi Arabia with three new combinations.

Samah A Alharbi,Rahmah N Al-Qthanin

doi:10.3897/phytokeys.174.58867

Abstract

This study provides a taxonomic revision for Ceropegia sect. Huernia in the flora of Saudi Arabia. Forty-six quantitative and qualitative morphological characters were analysed using principal component analysis (PCA), principal coordinates analysis (PCoA) and the unweighted pairs group using mean average (UPGMA) to separate and help delimit taxa. We propose to reduce the number of species reported in Saudi Arabia from 11 to four: C. khalidbinsultaniicomb. nov., C. laevis, C. lodarensis and C. macrocarpa. This study also suggested reducing two names to varietal level under C. lodarensis (var. foetidacomb. nov. and var. rubrostictacomb. nov.). A key to the species, detailed morphological descriptions, illustrations, distribution maps, ecology, etymology and preliminary conservation assessments are provided that follow IUCN criteria.

Highlights

The stapeliads, essentially stem-succulent leafless members of the tribe Ceropegieae (Asclepiadoideae, Apocynaceae), comprise 357 species placed in 31 genera
Cluster analysis by UPGMA of quantitative and qualitative data indicated the presence of four clearly-distinguished groups: Group 1, with H. arabica and H. laevis is the furthest away from all other groups; Group 2, consisting of H.asirensis, H. anagaynensis, H. khalidbinsultanii, H. radhwana, H. foetida and H. rubrosticta; Group 3, with H. lodarensis and H. boleana; and Group 4, with H. collenetteae and H. saudi-arabica (Fig. 2)
Accessions of Huernia collenetteae and H. saudiarabica were grouped in one cluster in the positive axes and weakly separated from individuals of H. rubrosticta, H. lodarensis and H. boleana (Fig. 3)

Summary

Introduction

The stapeliads, essentially stem-succulent leafless members of the tribe Ceropegieae (Asclepiadoideae, Apocynaceae), comprise 357 species placed in 31 genera. All of these were reduced to sections of Ceropegia after a broad circumscription of the genus, based.

Objectives

Methods

Results

Conclusion