44 research outputs found

    Justicia jamisonii Jongkind & Vollesen (Acanthaceae), a new species from Guinée, Côte d'Ivoire and Kenya

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    A new species, Justicia jamisonii is described and illustrated. It resembles Rungia paxiana but has a much narrower membranous margin on the inflorescence bracts and the corolla is hairy on the outside. The species has an extraordinary geographical distribution, it is only known from Guinée and Côte d’Ivoire in the west and Kenya in the east, two areas separated by a c. 4,700 km gap. It is described here in Justicia because the genus Rungia will soon be united with the older genus Justicia by the second author

    Madagascar's grasses and grasslands:anthropogenic or natural?

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    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics

    Alien plant invasions in tropical and sub-tropical savannas: patterns, processes and prospects

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    Flora of Tropical East Africa. Acanthaceae (Part 1).

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    Classification of Acanthaceae

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    The classification of Acanthaceae is discussed relative to recent molecular studies, pollen morphology, corolla aestivation and other potentially informative morphological homologues. The major pollen types of Acanthaceae are illustrated in the form of scanning electron micrographs. A three-item analysis of 11 morphological homologues is provided. A new classification of Acanthaceae is presented in addition to a list of generic synonymy

    Classification of Acanthaceae

    No full text
    The classification of Acanthaceae is discussed relative to recent molecular studies, pollen morphology, corolla aestivation and other potentially informative morphological homologues. The major pollen types of Acanthaceae are illustrated in the form of scanning electron micrographs. A three-item analysis of 11 morphological homologues is provided. A new classification of Acanthaceae is presented in addition to a list of generic synonymy

    Peplidium (Scrophulariaceae): a new generic record for The Flora of Tropical East Africa.

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    Two specimens of Peplidium maritimum (L.f.) Asch. (Scrophulariaceae /Phrymaceae) are recorded from the Indian Ocean coastline of Kenya, representing the first record of this species and genus for the Flora of Tropical East Africa. The generic key for the Flora volume is revised to accommodate this addition and a description is provided, together with notes on its distribution, habitat requirements and conservation status. The first Kenyan records of Limnophila indica (L.) Druce and Lindernia zanzibarica Eb.Fisch. & Hepper are also noted.Keywords: Peplidium maritimum, Limnophila indica, Lindernia zanzibarica, aquatic, Kenya, Lamu District, Tana District, generic ke
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