Morphological and anatomical studies of two medicinal plants: Harrisonia abyssinica Oliv. (Simaroubaceae) and Spathodea campanulata P. Beauv. (Bignoniaceae) and their systematic significance

The anatomy, morphology and trichome distribution o f leaves of two medicinal plants: Harrisonia abyssi nica Oliv. and Spathodea campanulata P. Beauv. from Nigeria we re studied in order to understand the usefulness of these characteristics for systematic purposes as well as provide useful pharmacopoeial information in additi on to previous identification tests available on the spec ies. Some anatomical characters such as the number and shape of epidermal cells, number of palisade and spongy pare nchyma layers of the leaf blade, and the trichome t ypes provide information of taxonomical significance. The specie s showed variations in stomata types, epidermal cel l shape, size and trichomes morphology. Most of the characters es pecially trichomes were diagnostic and used for dis tinguishing taxa. Trichomes were mostly multicellular and gland ular on adaxial surface of H. abyssinica, on the tw o surfaces of S. campanulata, they were glandular and non-glandul ar. Stellate hairs were observed in S. campanulata. Trichomes were well segmented in H. abyssinica. Trichomes of S. campanulata on abaxial surface had aggregates of 5 basalcells, in H. abyssinica there was just one basal ce ll. Leaf epidermal anatomy was reported for the fir st time in these species and was found taxonomically useful in the i dentification at the generic level.