Estudos taxonomicos sobre o genero Polygala L., subgenero Hebeclada (Chodat) Blake (Polygalaceae) no Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Polygala L. subg. Hebeclada (Chodat) Blake is an exclusively neotropical subgenus distributed from the southern United States to north Argentina, with a center of diversity in central-southeast Brazil occurring mainly in "cerrado" vegetation. Using partly different characters to discriminate the species of the subgenus, Chodat (1893) and Bernardi (2000) published considerably different taxonomic treatments. Thus, the goal of the present study is to evaluate the characters used in these revisions as a basis for a future formal revision of subg. Hebeclada. The present thesis is divided into three chapters: 1) Occurrence and distribution of glandular and eglandular trichomas on the outer sepals: Analysis of the taxonomic value in Brazilian species of Polygala subg. Hebeclada (Polygalaceae). The occurrence of glandular trichomes on the outer sepals provided data for the delimitation of some closely related species in Hebeclada. These species were accepted by Chodat (1893) but not by Bernardi (2000) and are accepted by us in the present treatment. 2) Palynotaxonomy of Brazilian species of Polygala subg. Hebeclada (Chodat) Blake. The present study demonstrated that the species as accepted by Chodat are palynologically homogenous in contrast to the species in the wider circumscription as accepted by Bernardi. 3) Taxonomy of Polygala subg. Hebeclada (Chodat) Blake from Brazil. Of the 25 species accepted by Chodat and 6 accepted by Bernardi we accept 12 species and 7 varieties for Brazil. Identification keys for the species and varieties are presented, as well as descriptions accompanied by illustrations and data about flowering and fruiting time, habitats and geographical distribution. In general, the treatment of Chodat (1893) was found to be more consistent than the one by Bernardi (2000)

ASSUNTO(S)

polygala taxonomy pallinology polygalaceae morphology taxonomia vegetal polygalaceae

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