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| Author(s): |
Juliana de Paula Souza
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2009-08-13 |
| Examining board members: |
Jose Rubens Pirani;
Milton Groppo Junior;
Lucia Garcez Lohmann;
Maria Candida Henrique Mamede;
Luciano Paganucci de Queiroz
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| Advisor: | Jose Rubens Pirani |
| Abstract | |
Violaceae is a widespread family, comprising 23 genera and approximately 900 species. Roughly half the species of the family belongs to the predominantly herbaceus genus Viola, which are concentrated the Northern Hemisphere and mountain areas at the tropical region. The shrub, tree and lianescent species occur mainly in tropical regions of the world. As traditionally recognized, Violeae comprises about 600 species, most of them belonging to Viola e Hybanthus, and the remaining are distributed among Agatea, Anchietea, Calyptrion, Hybanthopsis, Noisettia, Orthion and Schweiggeria. The tribe includes all lianescent genera of the family - Agatea A. Gray, Anchietea A.St.-Hil., Calyptrion Ging. and Hybanthopsis Paula-Souza, Agatea being the only extra-Neotropical genus, which is native to South Pacific islands. The objective of this study is to increase the knowledge we now have about this group of plants, through the taxonomical revision of the Neotropical lianescent genera of Violaceae (Anchietea, Calyptrion e Hybanthopsis), as well as a phylogenetic study including nearly all genera of the family, with emphasis on South American species, with the purpose of enlightening the relationships among taxa within tribe Violeae, and mostly, searching a better understanding of the relations within species of the polyphyletic Hybanthus. This study confirmed the polyphylly of tribe Violeae and Hybanthus, and grouped all South American species of this genus in a strongly supported clade (except for H. nanus). The four lianescent genera of the family were also grouped together, although the relationships of Hybanthopsis are still unclear in this lianescent clade. Fourteen lianescent species of Violaceae are found in the Neotropics, which occur almost exclusively on South America (except for Calyptrion arboreum, which extends through Central America up to Mexico) Anchietea (6 species) is widely distributed in South America, Calyptrion (7 species) occurs in Amazonia (and Mesoamerica with C. arboreum) and the monospecific Hybanthopsis is endemic to caatingas at southeastern Bahia in Brazil. Seven lectotypifications, three neotypifications, one status change and five new combinations were made, and five new species were discovered to science (two in Anchietea and three in Calyptrion). (AU) | |