C4 Photosynthesis: Convergence upon Convergence upon…

C4 photosynthesis has evolved independently numerous times in plants. New work suggests that these multiple origins are the result of recurring selection on a few amino acid positions in the key enzyme phosphoenolpyruvate carboxylase

Eleocharis yecorensis (Cyperaceae), a new species of spike-sedge from México

Eleocharis (Cyperaceae) includes approximately 200 species and is particularly diverse in the New World. A newly discovered species of subgenus Limnochloa is described from the states of Sonora and Mexico, Mexico. Eleocharis yecorensis is related to E. acutangula, E. mutata. and E. quadrangulata and can be distinguished from these species by its five-angled culms, obdeltoid achenes. and narrow neck between tubercle and achene body. In addition. E. yecorensis possesses root storage structures similar to those found in the Chinese water chestnut, Eleocharis dulcis

Glume absence in the Orcuttieae (Gramineae: Chloridoideae) and a hypothisis of intratribal relationships

This study addresses glume absence in tribe Orcuttieae. In Orcuttia califomica, O. inaequalis, and O. viscida, all spikelets possess two glumes except for the terminal spikelet of the inflorescence, which lacks both glumes. In O. pilosa and Tuctoria greenei the terminal spikelet lacks only the first (proximal) glume, whereas in O. tenuis, T. fragilis, and T. mucronata both glumes are developed on all spikelets. This is the first report of glume absence in species of Orcuttieae other than Neostapfia colusana, which has been long reported to lack both glumes on all spikelets. A hypothesis of phylogenetic relationships in the tribe is presented and characters involved are discussed. We hypothesize Neostapfia to be sister to a Tuctoria/Orcuttia clade, and Tuctoria to be a grade leading to a monophyletic Orcuttia

A Floristic Study in the Diamond Creek Drainage Area, Gila National Forest, New Mexico

The Diamond Creek drainage is one of the major watershed systems of the Gila National Forest in southwestern New Mexico. The purposes of this study were to catalog the vascular plants of a portion of this drainage area, describe the vegetation zones, locate any threatened, endangered, or sensitive plant species, and assess plant regeneration in areas that have been burned. The study area is located in the eastern portion of the Gila National Forest along the Black Range in the northwest corner of Sierra County. It covers approximately 5600 hectares (14000 acres) and ranges in elevation from 2250 to 3000 m (7400 to 9850 ft). Collected from the upper main Diamond Creek drainage area were 348 species including an additional six infraspecific taxa. The five largest families (by number of species and infraspecific taxa) in the study area were the Asteraceae (58), Poaceae (52), Fabaceae (24), Rosaceae (19), and Cyperaceae (17). The study area can be classified as Montane Coniferous Forest with most of the study area dominated by Pinus ponderosa and Pseudotsuga menziesii var. glauca. This overall vegetation type is fractured by narrow canyons, open meadows, perennial and intermittent streams, and rock outcrops. Three sensitive plant species were located in the study area: Erigeron scopulinus, Senecio sacramentanus, and Draba mogollonica. Two fires have occurred in the study area in recent times. These burned areas are primarily covered by shrubs including Quercus gambelii, Robinia neomexicana var. neomexicana, and Populus tremuloides

Chromosome Evolution in Cyperales

Karyotypic evolution is a prominent feature in the diversification of many plants and animals, yet the role that chromosomal changes play in the process of diversification is still debated. At the diploid level, chromosome fission and/or fusion are necessary components of chromosomal structural change associated with diversification. Yet the genomic features required for these events remain unknown. Here we present an overview of what is known about genomic structure in Cyperales, with particular focus on the current level of understanding of chromosome number and genome size and their impact in a phylogenetic context. We outline ongoing projects exploring genomic structure in the order using modern genomics techniques coupled with traditional data sets. Additionally, we explore the questions to which this approach might be best applied, and in particular, detail a project exploring the nature of genomic structural change at the diploid level in genus Carex, a group in which chromosome fission/fusion events are common and associated with diversification of many of its 2000 species. A hypothesized mechanism for chromosome number change in this genus is agmatoploidy, denoting changes in chromosome number without change in DNA amount through fission/fusion of holocentric chromosomes (chromosomes without localized centromeres). This project includes the creation of bacterial artificial chromosome (BAC) and expressed sequence tagged (EST) libraries to be used in physical and genetic linkage mapping studies in order to reveal the patterns of genome structural variation associated with agmatoploidy in Carex, and to explore the sequence and genic characteristics of chromosomal break points in the genome

Megaphylogenetic Specimen-Level Approaches to the Carex (Cyperaceae) Phylogeny Using ITS, ETS, and matK Sequences: Implications for Classification

We present the first large-scale phylogenetic hypothesis for the genus Carex based on 996 of the 1983 accepted species (50.23%). We used a supermatrix approach using three DNA regions: ETS, ITS and matK. Every concatenated sequence was derived from a single specimen. The topology of our phylogenetic reconstruction largely agreed with previous studies. We also gained new insights into the early divergence structure of the two largest clades, core Carex and Vignea clades, challenging some previous evolutionary hypotheses about inflorescence structure. Most sections were recovered as non-monophyletic. Homoplasy of characters traditionally selected as relevant for classification, historical misunderstanding of how morphology varies across Carex, and regional rather than global views of Carex diversity seem to be the main reasons for the high levels of polyphyly and paraphyly in the current infrageneric classification

Notas taxonómicas y de distribución de Carex (Cyperaceae) en el Neotrópico.

We present relevant data about the taxonomy and distribution of 20 species of the genus Carex in the Neotropics from the Caribbean region to Patagonia. We provide a total of 19 new records, two of them for species not previously recorded from South America, ten species newly reported from different countries, and seven species here reported as new regional records in Argentina, Bolivia, and Chile. We lectotypify nine species names (C. brehmeri, C. catharinensis, C. ecuadorica, C. firmicaulis,C. fuscula, C. mandoniana, C. phleoides, C. polysticha, and C. subantarctica) and epitypify one of these names (C. fuscula). Finally, we propose Carex koyamae as a new synonym of Carex phleoides.Notas taxonómicas y de distribución de Carex (Cyperaceae) en el Neotrópico. Presentamos datos relevantes acerca de la taxonomía y distribución de 20 especies del género Carex en el Neotrópico(de la region Caribe a la Patagonia). Aportamos un total de 19 registros nuevos, dos de ellos para especies hasta el momento no registradas para Sudamérica, diez especies citadas como novedad para diferentes países y siete especies aquí reportadas como novedades regionales en Argentina, Bolivia y Chile. Lectotipificamos de nueve nombres de especies (C. brehmeri, C. catharinensis, C. ecuadorica, C. firmicaulis, C. fuscula, C. mandoniana, C. phleoides, C. polysticha y C. subantarctica) y epitipificamos uno de ellos (C. fuscula). Finalmente, proponemos a Carex koyamae como nuevo sinónimo de Carex phleoides

Phylogeny of Cyperaceae Based on DNA Sequence Data–a New rbcL Analysis

Since the Monocots II meeting in 1998, significant new data have been published that enhance our systematic knowledge of Cyperaceae. Phylogenetic studies in the family have also progressed steadily. For this study, a parsimony analysis was carried out using all rbcL sequences currently available for Cyperaceae, including data for two new genera. One of the four subfamilies (Caricoideae) and seven of the 14 tribes (Bisboeckelereae, Cariceae, Cryptangieae, Dulichieae, Eleocharideae, Sclerieae, Trilepideae) are monophyletic. Subfamily Mapanioideae and tribe Chrysitricheae are monophyletic if, as the evidence suggests, Hellmuthia is considered a member of Cypereae. Some other features of our analysis include: well-supported Trilepideae and Sclerieae–Bisboeckelereae clades; a possible close relationship between Cryptangieae and Schoeneae; polyphyletic tribes Schoeneae and Scirpeae; the occurrence of Cariceae within the Dulichieae–Scirpeae clade, and a strongly supported clade, representing Cyperus and allied genera in Cypereae, sister to a poorly supported Ficinia–Hellmuthia– Isolepis–Scirpoides clade. Such patterns are consistent with other studies based on DNA sequence data. One outcome may be that only two subfamilies, Mapanioideae and Cyperoideae, are recognized. Much further work is needed, with efforts carefully coordinated among researchers. The work should focus on obtaining morphological and molecular data for all genera in the family