A Contribution to the Taxonomy of the Genus Fuirena Rottb. (cyperaceae) In Kenya

Abstract

The genus Fuirena poses taxonomic problems because the plants have reduced vegetative and reproductive structures. Some perennial taxa of the genus have been raised and lowered in rank at different times. Material collected at Kapsabet, presently called as Fuirena sp. A. cannot be identified using the key and descriptions on the family Cyperaceae in the flora in East Africa. Five perennial taxa in the genus Fuirena Rottb., occurring in Kenya, namely, F. stricta Steudel subsp. chlorocarpa (Ridl.) Lye, F. pubescens (poir.) Kunth var. pubescens, F. pubescens (Poir.) Kunth var. major Lye, F. pubescens (Poir.) Kunth var. buchananii (Boeck.) C. B. Cl., and Fuirena sp. A. have, been investigated with " reference to their taxonomy. Sources of taxonomic information used are morphology, anatomy, palynology and cytology. The taxon Fuirena sp, A has six perianth segments while F. pubescens (Poir.) Kunth var. pubescens has none. though in other characters such as the culm and leaf morphology they seem to be closely related. Culm anatomy of all the taxa shows a homogenous chlorenchyma without peripheral air cavities. while the spongy central ground tissue has irregular air spaces. The pollen grains of all taxa investigated are of Mapania type. The polar axis length measures up to 30.6~ in F. stricta subsp. chlorocarpa; 45.2Jl.m in Fuirena sp. A; 45.2Jl.m in F. pubescens var. pubescens; 54.8Jl.m in F. pubescens var. major; and 52.4Jl.m in F. pubescens VII. buchananii.iv The chromosome number determined at metaphase I is n=19 in F. stricta subsp. chlorocarpa; n=20 in Fuirena sp. A; n=21 in F. pubescens var. pubescens and var. major; and n=24, 40, 44, and 46 in F. pubescens var. buchananii. The chromosome counts are new records for the five taxa, while F. pubescens var. buchananii shows polyploidy and aneuploidy. A new taxon, Fuirena sp. A, has been recognised. (poir.) Kunth var. buchananii rank, namely F. buchananii Another taxon, F. pubescens (Boeck.) C. B. Cl. qualifies to be raised to a specific Boeck. stat. novo with two varieties. The current taxonomic treatment of F. pubescens (Poir.) Kunth var. pubescens, F. pubescens (poir.) Kunth var, major Lye and F. stricta Steudel subsp. chlorocarpa (Ridl.) Lye is supported by the present findings.