FACULTY OF SCIENCE
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Item Scanning electron microscopy of fruits in the West African polygonaceae(Institute of Botany, Chinese Academy of Sciences, 2010) Ayodele, A. E.; Zhou Z.The fruit morphology of 18 taxa representing seven genera of the family Polygonaceae in West Africa was investigated using scanning electron microscopy. The achenes are trigonous, lenticular, globose, subglobose, heart shaped, ovoid, or cone like. Sizes range from 0.12 × 0.10 cm2 in Polygonum plebeium to 7.87 × 0.58 cm2 in Afrobrunnichia erecta. Colors are brown to black. The cells are isodiametric in P. plebeium, irregular in A. erecta, Antigonon leptopus, and Harpagocarpus snowdenii, and polygonal in other species. The walls are straight, curved, or undulate and are either raised or depressed. Afrobrunnichia erecta is characterized by deeply sinuate lateral walls. The cell surface may be smooth or tuberculate or fibrillate in the family, usually covered with wax deposits. The combination of these characters is mainly taxonomically useful at the tribal level and rarely at the specific or infraspecific level for the delimitation of the taxa.Item The family polygonaceae in West Africa: taxonomic significance of leaf epidermal characters(Elsevier, 2006) Ayodele, A. E.; Olowokudejo, J. D.Comparative studies have been carried out on the leaf epidermal features of the species in the family Polygonaeae in West Africa. Epidermal cells are mainly isodiametric in Symmeria paniculata, irregular or more often polygonal with curved, straight and undulate to sinuate anticlinal walls. A few species e.g. Polygonum plebeium, Oxygonum sinuatum, Persicaria nepalensis and Harpagocarpus snowdenii have striations on their epidermal walls. All species except Afrobrunnichia erecta and H. snowdenii are amphistomatic and the family is characterized by a wide range of stomata types such as the anisocytic in P. plebeium, cyclocytic in S. paniculata and a few Persicaria, anomocytic, diacytic, parallelocytic and paracytic which is regarded as the basic type for the family based on its widest occurrence among the species. However, different stomata types may occur on the same leaf surface. The unicellular, or multicellular, uniseriate aggregated trichomes are significant in the recognition of taxa in the Persicaria except in P. senegalensis forma albotomentosa which has short uniseriate flagelliform trichomes. The significance of these observations is discussed in relation to the taxonomy of the family.Item The morphology and taxonomic significance of pollen in the West African polygonaceae(2005) Ayodele, A. E.The pollen of Polygonaceae in West Africa was studied by light microscopy. Three pollen types are recognized. Type A is typical of Polygonum represented by P. plebeium. These pollen grains are small, 17.5 x 12.5 µm to 22.5 x 15 µm, quadrangular and prolate with thin exine walls (1.5 - 2.5 µm). The Pollen type B is restricted to the Persicaria group. The pollen is of medium size, 34.3 - 45.5 µm polypantoporate, spheroidal with germ pores on the entire surface. Type C pollen is possessed by other genera studied. The grains range from small to large, 19.2 x 19.9 µm in Symmeria paniculata to 51.6 x 44 µm in Antigonon leptopus. They are subprolate, prolate-spheroidal to oblate-spheroidal, triangulate in polar view and oblong, elliptic to round in equatorial view. Palynological evidence supports the segregation of Persicaria from Polygonum as well as revealed that Harpagocarpus is better placed in the tribe Coccolobeae than in the tribe Persicareae.