1. A taxonomic study of the genus cryptolepis (periplocoideae: apocynaceae)
- Author
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Joubert, Lize, Venter, A. M., Venter, H. J. T., Bruyns, P. V., Joubert, Lize, Venter, A. M., Venter, H. J. T., and Bruyns, P. V.
- Abstract
English: Cryptolepis R.Br. (Apocynaceae, Periplocoideae) was taxonomically revised. Detailed descriptions of macro and micro-morphology, palynology, geographic distribution and ecological characteristics were presented. An identification key to the species was compiled and the nomenclature of all species was revised while all available type material was studied and lectotypes and neotypes were designated where necessary. Molecular phylogenetic analyses, based on the gene regions ITS, trnD–T and trnT–F, of representative species of 28 periplocoid genera and 22 Cryptolepis species were presented and the monophyly of Cryptolepis was evaluated. Historically a total of 81 species names and four subspecies names were published for Cryptolepis. However, a large number of species names were later placed in synonymy or transferred to other genera, while several new combinations were published. This resulted in a total of 29 accepted Cryptolepis species at the commencement of this study. Three new species, C. ibayana, C. thulinii and C. villosa, resulted from this study and the latter two were described in this thesis. One species, C. producta, was synonymised with C. oblongifolia. Cryptolepis, therefore, comprises a total of 31 species at present. In terms of species diversity, distribution and potential pharmaceutical and economic value, Cryptolepis is one of the most significant genera in the Periplocoideae. Cryptolepis grows throughout sub-Saharan Africa, the southern parts of Yemen, the island archipelago of Socotra, and southern Asia ranging from India to southern China, Taiwan, the Philippines and Indonesia. Most of the species grow in tropical forests or savannah, but 13 species are also adapted to arid environments. The majority of Cryptolepis species are concentrated in four centres of diversity along the east coast of Africa and on Socotra. These hotspots are associated with both arid and forest refugia in areas which have been regarded as local centres of endemism, Afrikaans: Cryptolepis R.Br. (Apocynaceae, Periplocoideae) is taksonomies hersien. Volledige beskrywings van die makro- en mikromorfologie, palinologie, geografiese verspreiding en ekologiese eienskappe is aangebied. 'n Uitkenningsleutel tot die spesies is opgestel, die nomenklatuur van al die spesies is hersien, terwyl alle beskikbare tipemateriaal bestudeer is en lekto- en neotipes is, waar nodig, aangewys. Molekulêre filogenetiese ontledings, gebaseer op die geenstreke ITS, trnD–T en trnT–F, van verteenwoordigende spesies van 28 periplokoide genusse en 22 Cryptolepis spesies is in die ondersoek ingesluit, en die monofilie van Cryptolepis is beoordeel. Histories is 'n totaal van 81 spesies en vier subspesies name vir Cryptolepis gepubliseer. 'n Groot aantal van hierdie spesiesname is egter later in sinonomie geplaas of na ander genusse oorgeplaas, terwyl 'n aantal nuwe kombinasies gepubliseer is. Met die aanvang van die huidige studie was daar dus 'n totaal van 29 erkende spesies in Cryptolepis. 'n Verdere drie nuwe spesies, C. ibayana, C. thulinii en C. villosa, is die resultaat van hierdie studie, waarvan die laasgenoemde twee in hierdie proefskrif beskryf is. Een spesie, C. producta, is in sinonomie met C. oblongifolia geplaas. Gevolglik sluit Cryptolepis tans 'n totaal van 31 spesies in. In terme van spesieverskeidenheid, verspreiding en potensiële farmaseutiese en ekonomiese belangrikheid is Cryptolepis een van die belangrikste genusse in die Periplocoideae. Cryptolepis kom dwarsdeur Afrika suid van die Sahara voor, maar ook in die suidelike deel van Jemen, in die Socotra eilandargipel en in suidelike Asië vanaf Indië tot suidelike Sjina, Taiwan, die Filippyne en Indonesië. Die spesies groei hoofsaaklik in tropiese woude of in savanna, maar 13 spesies word in droë omgewings aangetref. Die meeste Cryptolepis spesies is in vier diversiteitsentrums langs die ooskus van Afrika en op Socotra gekonsentreer. Hierdie brandpunte word met beide droë- en woudtoevlugniss
- Published
- 2013