Kamau, Peris .
Studies on the genus Pteris L. (Pteridaceae) in Tropical Africa.
Pteris L.(Pteridaceae) is large genus occupying a variety of ecological niches and represented by approximately 280 species globally. To-date, taxonomic revision has not been done for the ca. 25 species of tropical Africa,making identification and specific delimitation difficult. This study was designed to review the systematics of the genus Pteris in tropical Africa using morphological characters. Herbarium specimens and natural populations were studied to gather information. The study attempted to revise the taxonomy of Pteris in tropical Africa based on morphological and biogeographical information. Phenetic analysis using Statistica 7 yielded two major clades; the key character that was found to be stable in separating the taxa was lamina architecture where the first major clade had five species which were simply pinnate at times with 1 or 2 bifid basal pinnae. The second clade had 19 species with lamina pinnate-pinnatifid or highly divided. This second clade was further subdivided into two sub-clades, the first one had seven species with veins anastomosing in the lobes or forming narrow areoles along the costa. The second sub-clade has free veins in the lobes comprising 13 species which are widely distributed in all the African Phytochoria. Phylogenetic analysis using PAUP 4 software resulted in more or less complimentary clusters/clades. Some of the Pteris species occurring in this region are morphologically distinct whereas others are cryptically circumscribed,forming taxonomic complexes such as Pteris catoptera whose circumscription included several intermediates and morphotypes. Species boundary delimitation is further complicated by extensive interspecific hybridization such as demonstrated in Pteris atrovirens and P. burtonii.
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1 - National Museums of Kenya, Botany Department, P.O. Box 40658, Nairobi, Kenya, 00100, Kenya
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM