Two New Species of Stifftia with Notes on Relationships of the Genus (Asteraceae: Mutisieae)
1991; American Society of Plant Taxonomists; Volume: 16; Issue: 4 Linguagem: Inglês
10.2307/2418870
ISSN1548-2324
Autores Tópico(s)Plant Toxicity and Pharmacological Properties
ResumoA key is provided for the six known species of Stifftia including two newly described, S. hatschbachii and S. racemosa. Homogamous heads with actinomorphic corollas in Stifftia are considered as ultimately derived from members of the subtribe Mutisiinae having zygomorphic corollas, and the genus is not considered directly related to other genera with actinomorphic corollas such as Gochnatia of the subtribe Gochnatiinae. For purposes of the study the subtribe Gochnatiinae is not distinguished from the Mutisiinae. The genus Stifftia Mikan came to the attention of taxonomists early in the 19th century on the basis of two showy tree species occurring in Rio de Janeiro (Mikan 1820; Leandro do Sacramento 1820). As such, the genus was the first to be known of a series of mostly forest type Mutisie- ae occurring in eastern and northeastern South America. The generic concept was broadened for a time by Baker (1884) and Brown (1901) to include some of the related Guayana Highland species, but otherwise the only significant ad- dition to the genus until recently was the de- scription of an Amazonian species by Ducke (1935). The lack of changes has given the im- pression until recently of the lack of need of taxonomic work in the genus. Nevertheless, one new species has been described recently by Robinson and Kahn (1985) for Cayenne. Now, two more undescribed species have been dis- covered in eastern Brazil. The present occasion of the two species descriptions is taken to re- view briefly and key the six known species of the genus. Observations on relationships of the genus are also provided. There was a temporary extension of the con-
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