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University of KwaZulu-Natal (1987)

A study of the genera Justicia L. and Siphonoglossa oerst. (Acanthaceae) in southern Africa

Immelman, Kathleen Leonore

Titre : A study of the genera Justicia L. and Siphonoglossa oerst. (Acanthaceae) in southern Africa

Auteur : Immelman, Kathleen Leonore.

Université de soutenance : University of KwaZulu-Natal

Grade : Doctor of Philosophy 1987

Résumé partiel
A comprehensive revision of the genus Justicia L and, the closely related genera Siphonoglossa Oersted and Aulojusticia Lindau in southern Africa was undertaken as part of the Flora of Southern Africa project. Taxonomic characters re-examined include traditional morphological features and novel characters such as SEM studies of pollen seed and indumentum morphology, as well as chromatographic work on floral , pigments. Traditional morphological features examined included habit, the size and shape of leaves, the corolla, anthers and capsules. Inflorescence features were thoroughly re-examined. Pollen morphology was found to be diverse with three types of grain present in the genus. The number of colpi was either two or three and there were major differences in the appearance of the sexine. Pollen and inflorescence type were found to correlate. On the basis of this a natural infrageneric classification was proposed. The seeds showed a number of testa patterns : smooth, papillate, reticulate or with long scales. These types in many cases also correlated with the proposed infra-generic classification. The indumentum of leaves, stems and bracts was examined for each taxon, and in many cases proved valuable for identification of the taxon. The floral pigments were analysed using by 2D paper chromatography but, except in one species, did not prove useful in species or sectional delimitation. As a result of these studies, Justicia in southern Africa was divided into eight sections containing 22 species with six subspecies. One species and two subspecies were new and there is one new record for the region. These new taxa and a number of nomenclatural changes were published by Immelman (1986). The genus Aulojusticia was reassessed and is here regarded as a synonym of Siphonoglossa. Siphonoglossa, therefore, is considered’ here to include three species and one subspecies in the southern African region.


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