G. E. Ugbabe
National Institute for Pharmaceutical Research, Nigeria
The leaf surfaces and pollen grains of the Nigerian Bignoniaceae were studied using the scanning electron microscope (SEM). The species in this study were: Crescentia cujete Linn. Jacaranda mimosifolia D. Don. Kigelia africana (Lam) Benth. Markhamia tomentosa (Benth) K. Schum. , Newbuldia laevis (P. Beauv.) Seemann ex Bureau. Spathodea campanulata P. Beauv. Stereospermum acuminatissimum K. Schum. Stereospermum kunthianum Cham. Tabebuia rosea (Berthol) D. C. Tecoma stans (Linn) H, B &K. and Tecomeria capensis (Thunb.) Spach. Stomata were present on the abaxial surfaces of all the species studied. Sunken stomata were found in K. africana and J. mimosifolia while the others have raised stomata. Peltate trichomes were found on some species e.g., on the abaxial surfaces of C. cujete, J. mimosifolia, M. tomentosa, N. laevis T. stans and T. rosea; on the adaxial surfaces of C. cujete, M. tomentosa, N. laevis, S.acuminatissimum and T. rosea. M. tomentosa has both glandular and nonglandular trichomes on the abaxial surface while T. capensis has only non-glandular trichome on the adaxial surface. While the non-glandular trichomes of M. tomentosa were long and blunt, those of T. capensis were short and pointed. Striae were found on the adaxial surface of T. stans and on both the abaxial and adaxial surface of T. capensis. The pollen grains of species studied were of the tricolporate type being mostly circular except those of J. mimosifolia and T. stans which were elliptic. Ornamentation of the all the pollen were reticulate. The significance of these observations is discussed in relation to the taxonomy of the family.