The species are generally amphistomatic except Pandiaka heudelotii that is hypostomatic. Anomocytic and paracytic stomatal types were mostly found but cyclocytic and diacytic types may accompany, especially in Cyathula spp. The anticlinal wall pattern varies from undulate to curved and curvedstraight in the family. Other useful epidermal features are peltate scales, trichomes of different types such as candelabra type, unicellular and multicellular conical types, long acicular glandular forms that may be tuberculate or non-tuberculate and the filiform type; all can be employed at species level for delimitation purpose. Sub-familial grouping of the genera is supported while monophyly and polyphyly suggested in Gomphrenoideae and Amarantheae respectively can be inferred from the extent of character variations in the species. An indented dichotomous key is presented for species delimitation.

It is well known that interspecific hybrids occur in the genus Potamogeton. The linear‐leaved Potamogeton species commonly have highly variable morphological characteristics. Their hybrids often show similar vegetative characters to their parental species and their identification based solely on morphology is not always conclusive. In order to clarify whether there are any hybrids from the linear‐leaved Potamogeton plants collected in China, we used internal transcribed spacers (ITS) of nuclear ribosomal DNA and chloroplast rbcL gene sequences to identify the hybrids. Using ITS sequence additivity, we identified four hybrids, namely P. orientalis (P. pusillus×P. oxyphyllus), P. pusillus×P. berchtoldii, P. foliosus×P. octandrus, and P. cristatus×P. octandrus. The latter three hybrids should be considered as new hybrids in Potamogeton. The maternal parents of the four hybrids were confirmed using chloroplast rbcL gene sequences.

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A qualitative micromorphological assessment of the seven species of Isolona occurring in Nigeria and the Cameroons was undertaken with the aid of light microscope. The stomatal cells are particularly useful, providing stable characters which can be reliably employed in distinguishing the species. Hypostomatic leaves and paracytic stomatal type are generic constant. Possession of only paracytic stomata is characteristic of I. dewevrei whereas other species may have in addition another type such as 1+2 laterocytic stomatal type found only in I. zenkeri and presence of brachyparacytic stomata which shows relatedness of I. campanulata, I. congolana, I. hexaloba, I. pleurocarpus and I. thonneri. The epidermal surfaces appeared glabrous but an indication of hairs is shown by the presence of a glandular trichome base only in I. hexaloba. The epidermal cell characters such as epidermal cell shapes and anticlinal wall patterns seem to intergrade and they are not as definite as the stomatal cells. However, a combination of these features will be helpful in defining the species better and their leaf fragments can be differentiated based on the various characters studied for effective utilization in herbal medicinal research.

The epidermal features of the leaves of the six West African species of Afzelia were examined and compared using light and scanning electron microscopy. The leaves are hypostomatic in all species and stomatal type is paracytic. Anticlinal walls may be undulate or straight-curved and stomatal index ranges from 17.48% in A. bella var. gracilior to 25.20% in A. bipindensis. Porrect and flattened scales distinguish the infra-specific taxa of A. bella while presence of unicellular trichomes separates A. pachyloba from other species. The leaf surface is entirely covered by epicuticular wax deposits and the stomata are either raised or sunken in the genus. Using these foliar epidermal characters, an artificial key has been prepared to facilitate identification of the species. RESUMENCaracterísticas de la epidermis de las hojas de seis especies de Afzelia del Africa occidental fueron examinadas y comparadas usando microscopios de luz y electrónico. Las hojas son hipostomáticas en todas las especies, y presentan estomas paracíticos. Paredes anticlinales pueden ser onduladas o recto-curvadas, y el índice estomático va de 17,48% en A. bella var. gracilior a 25,20% en A. bipindensis. Escamas aplastadas y extendidas distinguen los taxa infraespecíficos de A. bella, mientras que la presencia de tricomas unicelulares separa a A. pachyloba de las demás especies. La superficie de las hojas está enteramente cubierta por depósitos de cera epicuticular, y los estomas se presentan elevados o hundidos. Usando estos caracteres epidérmicos foliares, se preparó una clave artificial para facilitar la identificación de las especies.

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