Molecular phylogeny of Gavilea (Chloraeinae: Orchidaceae) using plastid and nuclear markers.

A phylogenetic analysis is provided for 70% of the representatives of genus Gavilea, as well as for several species of the remaining genera of subtribe Chloraeinae: Bipinnula, Chloraea and Geoblasta. Sequences from the plastid markers rpoC1, matK-trnK and atpB-rbcL and the nuclear marker ITS, were analyzed using Maximum Parsimony and Bayesian Inference. Monophyly of subtribe Chloraeinae was confirmed, as well as its position inside tribe Cranichideae.

Understanding spikelet orientation in Paniceae (Poaceae).

Spikelet structure and grouping are key characters to identify grasses. Here we tested the possibility that spikelet pairs, a distinctive morphological structure of many Andropogoneae and Paniceae, are the starting point for a secondary single spikelet condition that can also explain the change of spikelet orientation among Paniceae genera. As a first approach, we studied the inflorescence development of Paspalum simplex, P.

Phylogeny of New World Stipeae (Poaceae): an evaluation of the monophyly of Aciachne and Amelichloa.

© The Willi Hennig Society 2010. ABSTRACT: The tribe Stipeae, with nearly 550 species, includes 28 core genera, of which 13 occur in America: Achnatherum, Aciachne, Amelichloa, Anatherostipa, Hesperostipa, Jarava, Nassella, Ortachne, Oryzopsis, Pappostipa, Piptatherum, Piptochaetium and Ptilagrostis. Based on 37 species representing 14 Stipeae genera, and using four chloroplast markers and morphological characters, we provide a phylogenetic hypothesis of the New World Stipeae, with our focus on Amelichloa and Aciachne.

Phylogenetic studies favour the unification of Pennisetum, Cenchrus and Odontelytrum (Poaceae): a combined nuclear, plastid and morphological analysis, and nomenclatural combinations in Cenchrus.

Backgrounds And Aims: Twenty-five genera having sterile inflorescence branches were recognized as the bristle clade within the x = 9 Paniceae (Panicoideae). Within the bristle clade, taxonomic circumscription of Cenchrus (20-25 species), Pennisetum (80-140) and the monotypic Odontelytrum is still unclear. Several criteria have been applied to characterize Cenchrus and Pennisetum, but none of these has proved satisfactory as the diagnostic characters, such as fusion of bristles in the inflorescences, show continuous variation.

Molecular phylogeny of the subtribe Melinidinae (Poaceae: Panicoideae: Paniceae) and evolutionary trends in the homogenization of inflorescences.

The subtribe Melinidinae (Poaceae: Panicoideae: Paniceae) includes 14 genera that present the PCK photosynthetic subtype in addition to several other unique and also common characters. The purpose of this research was (1) to test the monophyly of the subtribe Melinidinae, including 331 ndhF sequences of Panicoids and related genera, (2) to analyze the phylogenetic relationships among genera of Melinidinae using four cpDNA regions, and (3) to study evolutionary trends in the homogenization of inflorescences. As a result, the monophyly of Melinidinae is supported if Urochloa venosa is excluded from the subtribe.

Quantitative biogeography in the South America highlands-recognizing the Altoandina, Puna and Prepuna through the study of Poaceae.

The distribution data of 340 grass species sampled in a region of 53.219 km in the northwestern corner of Argentina (between ∼21°S and ∼24°S) were analyzed to search for concordance in species distributions by using the program NDM/VNDM. Here, the traditional biogeographic hypothesis proposed for the region is evaluated for the first time by using a quantitative method and an optimal criterion specifically developed within the context of areas of endemism.