This study examines the patterns of morphological variation and phenetic relationships among 11 species of Senna Mill. from Bangladesh using 32 vegetative and floral characters. The highest similarity is found between S. obtusifolia and S. tora, while the highest variation is observed between S. alata and S. hirsuta. UPGMA tree derived from cluster analysis reveals three major clusters, the first of which consists of two species (S. alata and S. auriculata), the second cluster comprises four species (S. hirsuta, S. obtusifolia, S. tora and S. occidentalis) and the third one is composed of five species (S. multiglandulosa, S. sophera, S. siamea, S. timoriensis and S. surattensis). A close relationship is also found between S. multiglandulosa and S. sophera, and between S. siamea and S. timoriensis. Results obtained from the present study are found congruent with cytological and anatomical studies showing the significance of numerical analysis for taxonomic relationship in the genus Senna.DOI: http://dx.doi.org/10.3329/bjpt.v20i1.15467Bangladesh J. Plant Taxon. 20(1): 77-83, 2013 (June)

Foliar epidermal characters of ten species of Senna Mill. found in Bangladesh are investigated. Anisocytic, anomocytic, paracytic, tetracytic and haxacytic stomata are found across the species. Anisocytic and paracytic stomata are common in all species. In addition to anisocytic and paracytic types, anomocytic stomata are found in Senna sophera and hexacytic stomata are observed in S. auriculata. Anticlinal wall is straight in S. alata, S. hirsuta, S. occidentalis, S. siamea and S. tora, curved in S. auriculata, S. sophera and S. siamea, and undulate in S. hirsuta and S. occidentalis. Glandular trichomes are observed in S. hirsuta and S. occidentalis, while non-gladular trichomes are predominant in the remaining species.