Taxonomic revision of the tropical African group of &lt;i&gt;Carex&lt;/i&gt; subsect. &lt;i&gt;Elatae&lt;/i&gt; (sect. &lt;i&gt;Spirostachyae&lt;/i&gt;, Cyperaceae)

Marcial Escudero,Modesto Luceño

doi:10.3989/ajbm.2256

Abstract

The tropical African monophyletic group of Carex subsect. Elatae (sect. Spirostachyae ) is distributed in continental tropical Africa, Madagascar, the Mascarene archipelago, and Bioko Island (32 km off the coast of West Africa, in the Gulf of Guinea). The first monographic treatment of this Carex group, as well as of the tribe Cariceae, was published by Kukenthal (as sect. Elatae Kuk.). Recently, the first molecular (nrDNA, cpDNA) phylogeny of Carex sect. Elatae has been published, which also included the species of sect. Spirostachyae . In the resulting consensus trees, most species of sect. Elatae were embedded within core Spirostachyae and so this section was joined with sect. Spirostachyae as subsect. Elatae . Within subsect. Elatae , several groups were described, one of which was termed the “tropical African group”. Here we present a taxonomic revision of this group, based on more than 280 vouchers from 29 herbaria as well as in field trips in Tropical Africa. In the revision, we recognise 12 species (16 taxa) within the tropical African group, and so have somewhat modified our previous view, in which 10 species, 12 taxa were listed. One new species from Tanzania is included in this treatment, C. uluguruensis Luceno & M. Escudero. Several combinations are made, C. cyrtosaccus is treated as a synonym of C. vallis-rosetto and, finally, the binomial C. greenwayi has been recognised.

Highlights

The tropical African group of Carex subsect
Spirostachyae) is a monophyletic group according to nrDNA phylogeny, but not according to cpDNA phylogeny (Escudero & Luceño, 2009)
This group is distributed along continental tropical Africa as well as Madagascar and the Mascarene and Bioko Islands

Summary

Introduction

The tropical African group of Carex subsect. Elatae Spirostachyae) is a monophyletic group according to nrDNA phylogeny, but not according to cpDNA phylogeny (Escudero & Luceño, 2009) This group is distributed along continental tropical Africa as well as Madagascar and the Mascarene and Bioko Islands. The first monographic treatment of this Carex group, as well as of tribe Cariceae, was published by Kükenthal (1909). He included 19 species in the new sect. Elatae Kük., eight of which (15 taxa) were from the tropical African group (Table 1) In this monographic work, one new species (C. mildbraediana) as well as five new varieties and two new combinations were published (Table 1). Subsequent treatments were local, as in the Flora of West Tropical Africa (Hooper & Napper, 1972; two species), or The Sedges and Rushes of East Africa (Haines & Lye, 1983; seven species, Table 1)

Objectives

Methods