The Taxonomic Significance of Certain Anatomical Variation in Four Genera of Asteraceae
by Essiett U. A., Archibong I. A. (2014)
U. A. Essiett and I. A. Archibong
Department of Botany and Ecological Studies University of Uyo, P. M. B. 1017, Uyo. Akwa Ibom State-Nigeria.
in Bull. Env. Pharmacol. Life Sci. (BEPLS), Vol 3 (5) April 2014: 150-163 –
Epidermal structures of four genera of Asteraceae from Akwa –Ibom State are described.
The fresh leaves of four species of Asteraceae (Bidens pilosa, Erigeron floribundus, Eclipta prostrata, and Aspilia africana) were collected.
The mature stomata types were diacytic, anisocytic, staurocyctic, anomocytic and brachyparacytic stomata. The anisocytic stomata were the commonest. Abnormalities observed here include unopened stomatal pore, stomata with one guard cell, aborted stomata, vertical and parallel contiguous stomata and one subsidiary cell shared by two stomata variously oriented. Diacytic stomata were distributed on both surfaces of B. pilosa but absent in A.africana, E. prostrata and E. floribundus. Parallel contiguous stomata were found only in the adaxial surface of E. floribundus and vertical contiguous stomata were also found only in the abaxial surfaces of E.prostrata and B. pilosa. Leaves are amphistomatic in B. pilosa and A.africana, but hypoamphistomatic in E. prostrata and E. floribundus. Glandular trichomes occurred in the abaxial surface of B. pilosa. Crystal druses are found on the abaxial surface of E. floribundus but absent in other species surfaces studied.
Other systematically useful characters are shapes of the epidermal anticlinal walls, stomata index and guard cell area can also be used for distinguishing the species.