Browsing by Author "Kelbessa, Ensermu"

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    A Palyological- Taxonomic Study of the: Genus Asystmlia and A Palynological S'rully of Some related Genera in the Acanthaceae
    (Addis Ababa University, 1982-06) Kelbessa, Ensermu; Hedberg, 0lov (Professor)
    The pollen morphology of nineteen species of Acanthaceael nine of AsystaEia and ten of five other genera have been investigated using light and/or electron microscopes. The five genera Graptophyllum, Jacobinia, Just;'cia, Hacka~ and styll~~ can be separated from each other by the number and character of apertures, exine stratification and/or by the nature of the "trema area". l'he study has revealed that the pollen grains of the genus Asystasia are three-porate and the surfaces are provided with nine colpoid streaks. The sexine is smooth. The species can be. separated from each other by the difference in the prominence of the colpoid streaks and by the nature of the sexinuous region around the pore. A detailed study of the pan-tl'opical species Ii. gangetica (L.) T. Anders. has resulted in its subdivision into two geographical subspecies on the basis of corolla and style and stigma lengths. It is also supported by pollen size and seed morphology. The subspecies with long corolla and style and stigma is designated as subsp. gangetica and the one with short corolla and style and stigma subsp. micrantha. The distribution of both taxa is illustrated.