ArticlePDF Available

Abstract

In preparing the treatment of the Orchidaceae for the Flora of the Venezuelan Guayana, several new taxa have been detected. These include specimens from recently completed expeditions and earlier herbarium material. Reconsideration of generic boundaries within several subtribes has made necessary various nomenclatural changes. The following new taxa and combinations are proposed: Cleistes huberi, sp. nov.; C. rosea f. pallida, f. nov.; C. unifoliata, comb. nov.; Octomeria romerorum, sp. nov.; Pleurothallis deborana, sp. nov.; P. pemonum, sp. nov.; Stelis garayi, comb. nov.; Sobralia oliva-estevae, sp. nov. In addition, comments are supplied, where pertinent, on the affinities of the various taxa proposed.
A preview of the PDF is not available
... S. sessilis and S. yauaperyensis produce terminal inflorescences with ovaries hidden between the floral bracts. Carnevali and Ramirez 1990) The taxonomic revision of Sobralia in the Guyanas 337 ...
Article
Full-text available
This paper presents a taxonomic revision of species of the genus Sobralia (Orchidaceae) in the Guyanas (Guyana, Suriname & French Guiana) based on an extensive study of herbarium material. Descriptions of their morphology, ecology and distribution are included and supported by illustrations of their habits and floral parts. A determination key is provided. Sobralia agnieszkae Baranow and Sobralia romeroana Baranow & Szlach.—two new species of the genus discovered among material collected in Guyana—are described. Including the newly described taxa, 14 species of the genus occur in the study area and, based on literature data, two further species (S. crocea (Poepp. & Endl.) Rchb.f. and S. fimbriata Poepp. & Endl.) are expected to be found there.
Article
Cleistes rosea and 10 other taxa comprise a complex widely distributed in various open vegetation types from eastern South America to Panama. The taxonomic identity of most of these taxa is unclear and their relationships with C. rosea have never been satisfactorily discussed or tested. Here, we employ molecular phylogenetics, morphometrics and morphological, ecological and geographic distribution data to investigate the relationships and taxonomy of Cleistes rosea and related species. Our results confirm that Cleistes rosea and Cleistes castaneoides are sister species and although highly similar in general floral morphology, they differ in vegetative characters, distribution, habitat, floral scent, and lip characters. Both species show local variations regarding floral characters, particularly the flower colour, and such differences were used here to delimit infraspecific taxa within the C. rosea/C. castaneoides clade. While C. rosea var. guianensis var. nov. is restricted to French Guiana, and C. rosea var. buenaventurae stat. & comb. nov. is restricted to low altitudes on the western side of the Cordillera Occidental in the Chocó region of Colombia, C. castaneoides var. castaneoides and C. castaneoides var. augusta comb. nov. are sympatric throughout their distribution. Cleistes abdita, formerly known as C. rosea f. pallida, is similar to C. castaneoides but distinguished by the smaller flowers and restricted distribution to Amazonian savannas. Cleistes rosea is distributed throughout the north of the Andes and northern South America. In turn, C. castaneoides occurs mainly in South-eastern and Central-western Brazil. Still, the distribution of these three species overlaps in the Guiana Shield, where the differentiation between them is less evident. Our results provide evidence of the plasticity of the floral morphology of Cleistes, especially the lip, and highlight that hitherto neglected characters, such as vegetative morphology, habitat, and floral scent, are particularly informative for the characterization of species and taxonomy of the genus.
Article
Full-text available
In this article we extend the geographic distribution of a rare Octomeria species, first described from Venezuela: Octomeria romerorum is reported for the first time from Brazil. Apart from considerably extending the distribution of the species, this record also represents the first documented collections since its description in 1990. We provide a short description of the species, as well as a photographic plate, data on its ecology and distribution, and taxonomic comments.
Article
Full-text available
In the course of preparing a generic treatment of the genus Stelis for Flora do Parana, southern Brazil, historical material and literature of several taxa related to Stelis ciliaris have been studied and their morphologies and nomenclature elucidated. Stelis leinigii, S. mystax-felis, and Stelis uhlii are herein proposed as new synonyms for Stelis ciliaris. A lectoptype is selected for Stelis jimenezii and a brief nomenclatural note on Stelis confusa is provided. Illustrations, updated synonym list, and taxonomic discussions are also presented for Stelis ciliaris.
Article
Full-text available
Une nouvelle espèce de Stelis, apparentée au morphogroupe Stelis ciliaris, est décrite, illustrée et comparée à une autre espèce brésilienne du même morphogroupe, Stelis garayi. Par ailleurs, cinq espèces du même genre sont enregistrées pour la première fois en Espírito Santo (Brésil). Abstract Nomenclatural notes within Stelis (Orchidaceae, Pleurothallidinae) in Espírito Santo (Brazil) – A new species belonging to the morphogroup Stelis ciliaris is described, illustrated and compared with another Brazilian species of the same morphogroup, Stelis garayi. Besides five species are newly reported from Espírito Santo.
Article
Hamilton, C. W. & Reichard, S. H.: Current practice in the use of subspecies, variety, and forma in the classification of wild plants. — Taxon 41: 485–498. 1992. — ISSN 0040‐0262. Infraspecific classification of plants continues to be practiced commonly by taxonomists: c. 8 % of species monographed in 26 major journals and series during the period 1987–1990 were subdivided. Of those, c. 42 % were divided into subspecies only, 52 % into varieties, 3 % into formae, and 3 % into taxa of more than one level. Subspecies and varieties are usually defined as requiring some integrity — geographic, ecologic, and/or phylogenetic — beyond the morphological. Despite some attempts to differentiate between subspecies and variety, they are largely equivalent in practice. European taxonomists tend to favor subspecies, whereas their counterparts in the United States usually employ variety. Formae usually are defined as lacking any extramorphological integrity. Given the general inconsistency of practice found, it is imperative that more authors state briefly their philosophy of infraspecific taxonomy so their classifications may be interpreted more clearly. Taxonomists collectively should promote greater standardization of infraspecific classification.
  • A Cogniaux
COGNIAUX, A. 1896. Flora Brasiliensis 3: 3 19-646.
Edicion especial del Instituto Bothico
  • E Foldats
FOLDATS, E. 1969. Orchidaceae. Pp. 129-145 in Flora de Venezuela 15(1). Edicion especial del Instituto Bothico, Caracas.
Icones Pleurothallidinarum 111. Systematics of Pleurothallis (Orchidaceae)
  • Monogr
  • Syst
Monogr. Syst.' Bot. Missouri Bot. Gard. 15. . 1986b. Icones Pleurothallidinarum 111. Systematics of Pleurothallis (Orchidaceae). Monogr. Syst. Bot. Missouri Bot. Gard. 20.
Orchids of Suriname: 214. VACO
  • M C M Werkhoven
WERKHOVEN, M. C. M. 1986. Orchids of Suriname: 214. VACO, Paramaribo.