Leaf morphology and anatomy of genus Androcymbium (Colchicaceae) in Southwest Africa

Abstract

Morphological and anatomical leaf studies were made in 32 populations belonging to 17 taxa of the genus Androcymbium in Southwest Africa. The morphological characters studied were corm and tunic characteristics, and number, distribution, shape, size, section, and color of leaves and bracts. The micromorphological characters were the leaf indument on both surface and margin, shape and size of epidermic cells, type and amount of stomata. Finally, the anatomical characters were mesophyll cell types, epidermic cell sizes, cellular wall types, size of central epidermic cells related to the other epidermic cells, and amount of idioblasts. The results showed a great heterogeneity in almost all characters analyzed. However, macromorphological characteristics related to color and shape of leaves and bracts in the genus Androcymbium could be used as indicators of taxonomic affinities among species. Conversely, the micromorphological and anatomical characteristics studied showed a great variation of types that does not agree with the interspecific relationships established from morphological, allozymatic or cpDNA RFLP data in other research carried out within the genus.