Taxonomic significance of the vegetative anatomy of members of genera Colocasia (L.) Schott and Xanthosoma (L.) Schott in the family Araceae

Anatomical attributes are important for taxonomic studies of plants.  This study investigated foliar and petiole anatomy of some members of the genera Colocasia and Xanthosoma. Similar and diagnostic characters critical for the taxonomy of the two genera were identified. The similar characters include, polygonal epidermal cell shape, straight adaxial anticlinal wall pattern, brachyparacytic stomata type, elliptic shaped stomata and unmodified raphide type. The presence of papillae on the adaxial surfaces of the members of genus Colocasia but not in the Xanthosoma taxa; lamellar collenchyma type in Xanthosoma mafaffa (Red), and unicellular non-glandular trichomes in Xanthosoma mafaffa (White) were recorded as diagnostic characters.   Key words: Brachyparacytic stomata, collenchyma, druses, foliar anatomy, petiole anatomy, papillae, raphides, trichome.