Nuytsia 7(2): 117-122 
117 
A new species of Trianthema (Aizoaeeae) from the 
Kimberley region and a note on T. triquetra 
by Volker Bitlrich 
Institut fur AUgemeine Botanik und Bolanischer Garten der Universitat Hamburg, 
Ohnhorstslr. 18, D-2000 Hamburg 52, Federal Republic ol Germany 
Abstract 
Bittrich, V. A new species of Trianthema (Aizoaeeae) from the Kimberley region and a note on T. triquetra. Nuytsia 
7(2): 117-122 (1990). A new species of Trianthema is described, namely T. kimberleyi Bitlrich & Jenssen, endemic to the 
Hall District of the Northern Botanical Province of Western Australia. Some observations on several forms of T. triquetra 
Willd. in Australia are provided: these differ mainly in leaf anatomy. 
Introduction 
The genus Trianthema L. (Aizoaeeae) consists of about 20 species distributed in the tropics and 
subtropics, mainly in the southern hemisphere. Until now, twelve species have been recorded from 
Australia: ten of these are endemics (Prescott 1984). 
The genus belongs to the subfamily Sesuvioideae (4 genera), which is characterized by 
circumscissile capsules, an aril completely sheathing the seed, Kranz anatomy of the leaves (with 
rare exceptions), and bracteate inflorescences (Bittrich & Hartmann 1988). The genus itself is 
defined by the monocarpellate gynoecium. Further characteristics are Lhe large-celled hypodermis 
of the leaves (probably functioning as a water storage organ) and the often myxospermous seeds, 
where the mucus is produced by the swelling of the aril after moistening, a feature also found in the 
closely related genus Zaleya Burm.f Jeffrey (1960) described two subgenera, Trianthema subgen. 
Trianthema and Trianthema subgen. Papularia (Forsk.) Jeffrey, distinguished by the number of 
ovules and the number of flowers per partial inflorescence. The new species described here is 
included in the subgen. Trianthema. T. triquetra belongs to the subgen. Papularia. However, it 
needs to be investigated whether the two subgencra defined by Jeffrey (I960) are also monophyleLic 
groups and the characters mentioned by him provide synapomorphics for one or both of these 
subgenera. 
