Miocene-Pliocene speciation, introgression, and migration of Patis and Ptilagrostis (Poaceae: Stipeae).

Genetic interchange between American and Eurasian species is fundamental to our understanding of the biogeographical patterns, and we make a first attempt to reconstruct the evolutionary events in East Asia that lead to the origin and dispersal of two genera, Patis and Ptilagrostis. We conducted a molecular phylogenetic study of 78 species in the tribe Stipeae using four plastid DNA sequences (ndhF, rpl32-trnL, rps16-trnK, and rps16 intron) and two nuclear DNA sequences (ITS and At103). We use single copy nDNA gene At103 for the first time in the grasses to elucidate the evolutionary history among members of the Stipeae. Ampelodesmos, Hesperostipa, Oryzopsis, Pappostipa, Patis, and Stipa are found to be of multiple origins. Our phylograms reveal conflicting positions for Ptilagrostis alpina and Pt. porteri that form a clade with Patis coreana, P. obtusa, and P. racemosa in the combined plastid tree but are aligned with other members of Ptilagrostis in the ITS tree. We hypothesize that Ptilagrostis still retains the nucleotype of an extinct genus which transited the Bering land bridge from American origins in the late Miocene (minimum 7.35-6.37 mya) followed by hybridization and two plastid capture events with a Trikeraia-like taxon (7.96 mya) and para-Patis (between 5.32 and 3.76 mya). Ptilagrostis porteri and Patis racemosa then migrated to continental North America 1.7-2.9 mya and 4.3-5.3 mya, respectively.

Phylogeny of the Centaurea group (Centaurea, Compositae) - geography is a better predictor than morphology.

The Centaurea group is part of the Circum-Mediterranean Clade (CMC) of genus Centaurea subgenus Centaurea, a mainly Mediterranean plant group with more than 200 described species. The group is traditionally split on morphological basis into three sections: Centaurea, Phalolepis and Willkommia. This division, however, is doubtful, especially in light of molecular approaches. In this study we try to resolve this phylogenetic problem and to consolidate the circumscription and delimitation of the entire group against other closely related groups. We analyzed nuclear (internal transcribed spacer of the ribosomal genes) and chloroplast (rpl32-trnL intergenic spacer) DNA regions for most of the described species of the Centaurea group using phylogenetic and network approaches, and we checked the data for recombination. Phylogeny was used to reconstruct the evolution of the lacerate-membranaceous bract appendages using parsimony. The magnitude of incomplete lineage sorting was tested estimating the effective population sizes. Molecular dating was performed using a Bayesian approach, and the ancestral area reconstruction was conducted using the Dispersal-Extinction-Cladogenesis method. Monophyly of the Centaurea group is confirmed if a few species are removed. Our results do not support the traditional sectional division. There is a high incongruence between the two markers and between genetic data and morphology. However, there is a clear relation between geography and the structure of the molecular data. Diversification in the Centaurea group mainly took place during the Pliocene and Pleistocene. The ancestral area infered for the Circum-Mediterranean Clade of Centaurea is the Eastern Mediterranean, whereas for the Centaurea group it is most likely NW-Africa. The large incongruencies, which hamper phylogenetic reconstruction, are probably the result of introgression, even though the presence of incomplete lineage sorting as an additional factor cannot be ruled out. Convergent evolution of morphological traits may have led to incongruence between morphology-based, traditional systematics and molecular results. Our results also cast major doubts about current species delimitation.

Taxonomic revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Central America: phylogeny and classification.

A taxonomic treatment of 38 species of Muhlenbergia, a phylogeny based on analysis of six DNA sequence markers, and classification of Muhlenbergia for Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama; and Campeche, Chiapas, Quintana Roo, Tabasco, and Yucatán, México) is given. With the support from a molecular phylogeny we describe Muhlenbergiasubg.Ramulosaesubgen. nov. In our treatment we place M.gigantea (younger name) as a synonym of M.mutica. Lectotypes are designated for the names Agrostismicrosperma Lag., Epicampesgigantea E. Fourn., Lamarckiatenella DC., Muhlenbergiaadspersa Trin., M.diversiglumis Trin., M.exilis E. Fourn., M.flabellata Mez, M.setarioides E. Fourn., Pereilemaciliatum E. Fourn., P.crinitumvar.cirratum E. Fourn., Podosemumciliatum Kunth, P.tenuissimum J. Presl, and Schellingiatenera Steud.

A molecular phylogeny and classification of Leptochloa (Poaceae: Chloridoideae: Chlorideae) sensu lato and related genera.

BACKGROUND AND AIMS: Leptochloa (including Diplachne) sensu lato (s.l.) comprises a diverse assemblage of C(4) (NAD-ME and PCK) grasses with approx. 32 annual or perennial species. Evolutionary relationships and a modern classification of Leptochloa spp. based on the study of molecular characters have only been superficially investigated in four species. The goals of this study were to reconstruct the evolutionary history of Leptochloa s.l. with molecular data and broad taxon sampling. METHODS: A phylogenetic analysis was conducted of 130 species (mostly Chloridoideae), of which 22 are placed in Leptochloa, using five plastid (rpL32-trn-L, ndhA intron, rps16 intron, rps16-trnK and ccsA) and the nuclear ITS 1 and 2 (ribosomal internal transcribed spacer regions) to infer evolutionary relationships and revise the classification. KEY RESULTS: Leptochloa s.l. is polyphyletic and strong support was found for five lineages. Embedded within the Leptochloa sensu stricto (s.s.) clade are two Trichloris spp. and embedded in Dinebra are Drake-brockmania and 19 Leptochloa spp. CONCLUSIONS: The molecular results support the dissolution of Leptochloa s.l. into the following five genera: Dinebra with 23 species, Diplachne with two species, Disakisperma with three species, Leptochloa s.s. with five species and a new genus, Trigonochloa, with two species.

A phylogeny of the Triraphideae including Habrochloa and Nematopoa (Poaceae, Chloridoideae).

To investigate the evolutionary relationships among species of the tribe Triraphideae (including two monotypic genera, Habrochloa and Nematopoa), we generated a phylogeny based on DNA sequences from nuclear ribosomal (ITS) and four plastid markers (rps16-trnK, rps16 intron, rpl32-trnL, and ndhA intron). Habrochloa and Nematopoa form a clade that is sister to Neyraudia and Triraphis. Member of the Triraphideae have paniculate inflorescences, 3-veined, marginally ciliate lemmas, usually with hairy lateral veins, that are apically bifid and awned from between a sinus. A description of the Triraphideae and key to the genera is provided, and the biogeography is discussed, likely originating in Africa.

Centaurea Subsect. Phalolepis (Compositae, Cardueae): A Case Study of Mountain-Driven Allopatric Speciation in the Mediterranean Peninsulas.

Centaurea subsection Phalolepis has been thoroughly analyzed in previous studies using microsatellites in four centers of speciation: Anatolia, Greece, the Italian Peninsula and the Iberian Peninsula. Evidence suggests a correlation between taxon diversity and mountains. This group constituted a good case study for examining the mountain-geobiodiversity hypothesis (MGH), which explains the possible reasons for the many radiations occurring in mountains across the world. We combined all the datasets and carried out analyses of their genetic structure to confirm the species of subsect. Phalolepis are grouped according to a geographic pattern. We then checked whether climatic fluctuations favored the "species pump" hypothesis in the mountains by using the Climatic Stability Index (CSI). Finally, the relief of the terrain was tested against the rate of allopatric speciation by region by means of Terrain Ruggedness Index and environmental gradients through our new Climate Niche Breadth Index. Our results supported the MGH hypothesis and confirmed that the main triggers, namely altitudinal zonation, climatic oscillations and rugged terrain, must be present for the development of a radiation.

A classification of the Chloridoideae (Poaceae) based on multi-gene phylogenetic trees.

We conducted a molecular phylogenetic study of the subfamily Chloridoideae using six plastid DNA sequences (ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3, and rpl32-trnL) and a single nuclear ITS DNA sequence. Our large original data set includes 246 species (17.3%) representing 95 genera (66%) of the grasses currently placed in the Chloridoideae. The maximum likelihood and Bayesian analysis of DNA sequences provides strong support for the monophyly of the Chloridoideae; followed by, in order of divergence: a Triraphideae clade with Neyraudia sister to Triraphis; an Eragrostideae clade with the Cotteinae (includes Cottea and Enneapogon) sister to the Uniolinae (includes Entoplocamia, Tetrachne, and Uniola), and a terminal Eragrostidinae clade of Ectrosia, Harpachne, and Psammagrostis embedded in a polyphyletic Eragrostis; a Zoysieae clade with Urochondra sister to a Zoysiinae (Zoysia) clade, and a terminal Sporobolinae clade that includes Spartina, Calamovilfa, Pogoneura, and Crypsis embedded in a polyphyletic Sporobolus; and a very large terminal Cynodonteae clade that includes 13 monophyletic subtribes. The Cynodonteae includes, in alphabetical order: Aeluropodinae (Aeluropus); Boutelouinae (Bouteloua); Eleusininae (includes Apochiton, Astrebla with Schoenefeldia embedded, Austrochloris, Brachyachne, Chloris, Cynodon with Brachyachne embedded in part, Eleusine, Enteropogon with Eustachys embedded in part, Eustachys, Chrysochloa, Coelachyrum, Leptochloa with Dinebra embedded, Lepturus, Lintonia, Microchloa, Saugetia, Schoenefeldia, Sclerodactylon, Tetrapogon, and Trichloris); Hilariinae (Hilaria); Monanthochloinae (includes Distichlis, Monanthochloe, and Reederochloa); Muhlenbergiinae (Muhlenbergia with Aegopogon, Bealia, Blepharoneuron, Chaboissaea, Lycurus, Pereilema, Redfieldia, Schaffnerella, and Schedonnardus all embedded); Orcuttiinae (includes Orcuttia and Tuctoria); Pappophorinae (includes Neesiochloa and Pappophorum); Scleropogoninae (includes Blepharidachne, Dasyochloa, Erioneuron, Munroa, Scleropogon, and Swallenia); Traginae (Tragus with Monelytrum, Polevansia, and Willkommia all embedded); Tridentinae (includes Gouinia, Tridens, Triplasis, and Vaseyochloa); Triodiinae (Triodia); and the Tripogoninae (Melanocenchris and Tripogon with Eragrostiella embedded). In our study the Cynodonteae still include 19 genera and the Zoysieae include a single genus that are not yet placed in a subtribe. The tribe Triraphideae and the subtribe Aeluropodinae are newly treated at that rank. We propose a new tribal and subtribal classification for all known genera in the Chloridoideae. The subfamily might have originated in Africa and/or Asia since the basal lineage, the Triraphideae, includes species with African and Asian distribution.

Eriocoma valdesii, a new species from México (Poaceae, Stipeae).

Eriocoma valdesii sp. nov., is described and illustrated. The new species was found growing on calcareous rocky slopes and hillsides between 1700-2721 m in Coahuila, Nuevo León, San Luis Potosí, and Tamaulipas. The new species is morphologically similar to Eriocoma lobata but differs in having ligules (2-) 4.5-8.5 mm long with acute to narrowly acute and lacerate apices and florets with a sharp-pointed callus. In addition, we include a key to the species of Eriocoma in northeastern México.

ResumenSe describe e ilustra una nueva especie, Eriocoma valdesii sp. nov. La nueva especie se encontró creciendo en laderas calcáreas rocosas y laderas entre 1700­2721 m en Coahuila, Nuevo León, San Luis Potosí y Tamaulipas. La nueva especie es morfológicamente similar a Eriocoma lobata, pero difiere en tener lígulas de (2­) 4.5­8.5 mm de largo con ápices y flósculos agudos a estrechamente agudos y lacerados con un callo puntiagudo. Además, incluimos una clave para las especies de Eriocoma en el noreste de México.

A phylogeny of species near Agrostis supporting the recognition of two new genera, Agrostula and Alpagrostis (Poaceae, Pooideae, Agrostidinae) from Europe.

Based on a molecular DNA phylogeny of three plastid (rpl32-trnK, rps16 intron, and rps16-trnK) and nuclear ITS regions investigating 32 species of Agrostidinae, we describe two new genera, Agrostula gen. nov. with a single species and Alpagrostis gen. nov. with four species; provide support for five species in a monophyletic Podagrostis; and include a small sample of 12 species of a monophyletic Agrostis s.s. (including the type and most species of Neoschischkinia), that separates into two clades corresponding to A. subg. Agrostis and A. subg. Vilfa. Agrostula differs from Agrostis in having leaf blades with pillars of sclerenchyma which are continuous between the adaxial and abaxial surface of the blades, dorsally rounded glumes with blunt to truncate and erose to denticulate apices, florets ½ the length of the glumes, lemmas equally wide as long, widest at (or near) apex, apices broadly truncate, irregularly 5 to 7 denticulate to erose, awnless, anthers longer than the lemmas, and rugose-papillose caryopses. Alpagrostis differs from Agrostis in having geniculate basally inserted awns and truncate lemma apices with lateral veins prolonged from the apex in (2)4 setae. The following eight new combinations are made: Agrostula truncatula, Agrostula truncatula subsp. durieui, Alpagrostis alpina, Alpagrostis alpina var. flavescens, Alpagrostis barceloi, Alpagrostis setacea, Alpagrostis setacea var. flava, and Alpagrostis schleicheri. In addition, we provide a key separating Agrostula and Alpagrostis from Agrostis s.s. and other genera previously considered as synonyms of Agrostis; lectotypify Agrostis alpina Scop., A. schleicheri Jord. & Verl., A. truncatula Parl., and A. truncatula var. durieui Henriq.; and neotypify A. setacea Curtis.

ResumenSobre la base de una filogenia molecular de ADN de tres regiones plastidiales (rpl32-trnK, rps16 intrón y rps16-trnK) e ITS nuclear de 32 especies de Agrostidinae, describimos dos nuevos géneros, Agrostula gen. nov. con una sola especie, y Alpagrostis gen. nov. con cuatro especies; mostramos el apoyo para las cinco especies dentro de Podagrostis monofilético; e incluimos una pequeña muestra de 12 especies de Agrostis s.s (que incluye el tipo y la mayoría de las especies de Neoschischkinia), este último dividido en dos subclados que corresponden a A. subg. Agrostis y A. subg. Vilfa. Agrostula se diferencia de otras especies de Agrostis por tener láminas foliares con haces de esclerénquima continuos entre las superficies adaxial y abaxial de los limbos, glumas de dorso redondeado y ápice embotado a truncado y eroso a denticulado, antecios de ½ de la longitud de las glumas, lemas tan anchas como largas, lo más ancho en o cerca del ápice, ápices anchamente truncados, irregularmente 5 a 7 denticulados o erosos, sin arista, anteras más largas que los lemas y cariopsis rugosa-papilosa. Alpagrostis se diferencia de otras especies de Agrostis por tener aristas geniculadas insertas basalmente y ápices de lema truncados con venas laterales que se prolongan en (2)4 arístulas apicales. Presentamos las siguientes ocho nuevas combinaciones: Agrostula truncatula, Agrostula truncatula subsp. durieui, Alpagrostis alpina, Alpagrostis alpina var. flavescens, Alpagrostis barceloi, Alpagrostis setacea, Alpagrostis setacea var. flava y Alpagrostis schleicheri. Además, proporcionamos una clave que separa Agrostula y Alpagrostis de Agrostis s.s. y otros géneros previamente considerados como sinónimos de Agrostis, lectotipificamos Agrostis alpina Scop., A. schleicheri Jord. & Verl., A. truncatula Parl. y A. truncatula var. durieui Henriq. y neotipificamos A. setacea Curtis.

New combinations and updated descriptions in Podagrostis (Agrostidinae, Poaceae) from the Neotropics and Mexico.

Based on morphological study and corroborated by unpublished molecular phylogenetic analyses, five grass species of high-mountain grasslands in Mexico, Central and South America, Agrostis bacillata, A. exserta, A. liebmannii, A. rosei, and A. trichodes, are transferred to Podagrostis and bring the number of species of this genus recognized in the New World to ten. The name Apera liebmannii is lectotypified and epitypified. We provide an updated genus description for Podagrostis, and updated species descriptions, images, and notes on the new combinations. The diagnostic characteristics differentiating Podagrostis from Agrostis are: a) palea that reaches from (2/3) ¾ to almost the apex of the lemma; b) florets that usually almost equal the length of the glumes or are at least ¾ the length of the glumes; c) rachilla extension present and emerging from under the base of the palea as a slender short stub (rudimentary or up to 1.4 mm long, sometimes obscure in most florets in P. rosei), smooth or scaberulous, glabrous or distally pilulose (hairs < 0.3 mm long); d) lemmas usually awnless, sometimes with a short straight awn 0.2-0.6 mm long, inserted medially or in the upper 1/3 of the lemma, not surpassing the glumes (awn well-developed, straight or geniculate and inserted in lower 1/3 of lemma, not or briefly surpassing glumes in P. rosei). We include a generic key to distinguish the species of Podagrostis from other similar genera in Latin America and a key to distinguish the species of Podagrostis now accepted as occurring in these areas.

ResumenBasado en estudios morfológicos y corroborado por datos no publicados de análisis filogenéticos, las cinco gramíneas de alta montaña de los pastizales en México, Centroamérica y Sur América Agrostis bacillata, A. exserta, A. liebmannii, A. rosei, y A. trichodes, son transferidos a Podagrostis incrementando a diez el número de especies en el nuevo mundo de este reconocido género. El nombre de Apera liebmannii también es lectotipificado y epitipicado. Proporcionamos una descripción actualizada del género Podagrostis, y descripciones actualizadas de las especies, imágenes y comentarios sobre las nuevas combinaciones. Las características diagnósticas que diferencian a Podagrostis de Agrostis son: a) pálea de 2/3-¾ hasta casi el ápice de la lemma; b) espiguillas, generalmente casi iguales en longitud a las glumas o de al menos ¾ la longitud de las glumas; c) extensión de la raquilla presente y emergiendo desde debajo de la base de la pálea como un trozo corto y delgado (desde rudimentario hasta de 1.4 mm de largo, a veces oscuro en la mayoría de los flósculos en P. rosei), liso o escabérulo, glabro o piloso distalmente (pelos < 0.3 mm de largo); d) lemmas generalmente sin arista, o a veces con arista corta y recta de 0.2­0.6 mm de largo, insertada medialmente o en el tercio superior de la lemma, sin sobrepasar las glumas (arista bien desarrollada, recta o geniculada e insertada en la parte inferior 1/3 de lemma, no o superando brevemente las glumas en P. rosei). Incluimos una clave para distinguir Podagrostis de otros géneros similares presentes en América Latina y una clave para distinguir las especies de Podagrostis ahora aceptadas por estar presentes en estas áreas.

A key to the North American genera of Stipeae (Poaceae, Pooideae) with descriptions and taxonomic names for species of Eriocoma, Neotrinia, Oloptum, and five new genera: Barkworthia, ×Eriosella, Pseudoeriocoma, Ptilagrostiella, and Thorneochloa.

Based on earlier molecular DNA studies we recognize 14 native Stipeae genera and one intergeneric hybrid in North America. We provide descriptions, new combinations, and 10 illustrations for species of Barkworthia gen. nov., Eriocoma, Neotrinia, Oloptum, Pseudoeriocoma gen. nov., Ptilagrostiella gen. nov., Thorneochloa gen. nov., and ×Eriosella nothogen. nov. The following 40 new combinations are made: Barkworthiastillmanii, Eriocomaalta, E.arida, E.arnowiae, E.bloomeri, E.bracteata, E.contracta, E.coronata, E.curvifolia, E.hendersonii, E.latiglumis, E.lemmonii, E.lemmoniissp.pubescens, E.lettermanii, E.lobata, E.nelsonii, E.nelsoniissp.dorei, E.nevadensis, E.occidentalis, E.occidentalisssp.californica, E.occidentalisssp.pubescens, E.parishii, E.parishiissp.depaupertata, E.perplexa, E.pinetorum, E.richardsonii, E.robusta, E.scribneri, E.swallenii, E.thurberiana, E.wallowaensis, ×Eriosellacaduca, Pseudoeriocomaacuta, P.constricta, P.editorum, P.eminens, P.hirticulmis, P.multinodis, Ptilagrostiellakingii, and Thorneochloadiegoensis. A key to the native and introduced genera of North American Stipeae, and an overview of the tribe in North America and worldwide are given. Lectotypes are designated for Eriocomacuspidata Nutt., Fendleriarhynchelytroides Steud., Stipabloomeri Bol., Stipacoronata Thurb., Stipamembranacea Pursh, Stipamormonum Mez, Stiparichardsonii Link, and Stipawilliamsii Scribn. Achnatherum s.s. and Piptatherum s.s. are now restricted to Eurasia and the Mediterranean/Asia, respectively.

ResumenBasados en estudios anteriores de ADN molecular, reconocemos 14 géneros nativos de Stipeae y un híbrido intergenérico en América del Norte. Se presentan descripciones, nuevas combinaciones, y 10 ilustraciones para las especies de Barkworthia gen. nov., Eriocoma, Neotrinia, Oloptum, Pseudoeriocoma gen. nov., Ptilagrostiella gen. nov., Thorneochloa gen. nov. y ×Eriosella nothogen. nov. Se realizan las siguientes 40 nuevas combinaciones: Barkworthiastillmanii, Eriocomaalta, E.arida, E.arnowiae, E.bloomeri, E.bracteata, E.contracta, E.coronata, E.curvifolia, E.hendersonii, E.latiglumis, E.lemmonii, E.lemmoniissp.pubescens, E.lettermanii, E.lobata, E.nelsonii, E.nelsoniissp.dorei, E.nevadensis, E.occidentalis, E.occidentalisssp.californica, E.occidentalisssp.pubescens, E.parishii, E.parishiissp.depaupertata, E.perplexa, E.pinetorum, E.richardsonii, E.robusta, E.scribneri, E.swallenii, E.thurberiana, E.wallowaensis, ×Eriosellacaduca, Pseudoeriocomaacuta, P.constricta, P.editorum, P.eminens, P.hirticulmis, P.multinodis, Ptilagrostiellakingii y Thorneochloadiegoensis. Se presenta una clave para los géneros nativos e introducidos de las especies norteamericanas, y una visión general de la tribu en América del Norte y en todo el mundo. Se designan lectotipos para Eriocomacuspidata Nutt., Fendleriarhynchelytroides Steud., Stipabloomeri Bol., Stipacoronata Thurb., Stipamembranacea Pursh, Stipamormonum Mez, Stiparichardsonii Link y Stipawilliamsii Scribn. Achnatherum s.s. y Piptatherum s.s. ahora están con distribución restringida- a Eurasia y el Mediterráneo/Asia, respectivamente.

Phylogeny of Muhlenbergia subg. Pseudosporobolus, including M. spatha (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) now found in Zacatecas, Mexico.

Muhlenbergia spatha, previously known only from near the type locality in San Luis Potosí, is reported from two localities in Zacatecas, Mexico. Historically, botanists have overlooked this diminutive annual. To clarify affinities of M. spatha, we present a molecular phylogeny emphasising species in M. subg. Pseudosporobolus using sequence data from two plastid markers (rpl32-trnL and rps16 intron) and nrDNA ITS. In addition, we include an updated description, illustration and discussion of the habitat of M. spatha.

Resumen Muhlenbergia spatha, anteriormente conocida solo cerca de la localidad tipo en San Luis Potosí, se reporta en dos localidades en Zacatecas, México. Históricamente, los botánicos han pasado por alto esta diminuta anual. Para aclarar las afinidades de M. spatha, presentamos una filogenia molecular que enfatiza especies en M. subg. Pseudosporobolus usando datos de secuencia de dos marcadores plástidos (rpl32-trnL e rps16 intron) y nrADN EIT. Además, incluimos una descripción actualizada, ilustración y discusión del hábitat de M. spatha.

Monograph of Diplachne (Poaceae, Chloridoideae, Cynodonteae).

Diplachne P. Beauv. comprises two species with C4 (NAD-ME) photosynthesis. Diplachne fusca has a nearly pantropical-pantemperate distribution with four subspecies: D. fusca subsp. fusca is Paleotropical with native distributions in Africa, southern Asia and Australia; the widespread Australian endemic D. f. subsp. muelleri; and D. f. subsp. fascicularis and D. f. subsp. uninervia occurring in the New World. Diplachne gigantea is known from a few widely scattered, older collections in east-central and southern Africa, and although Data Deficient clearly is of conservation concern. A discussion of previous taxonomic treatments is provided, including molecular data supporting Diplachne in its newer, restricted sense. Many populations of Diplachne fusca are highly tolerant of saline substrates and most prefer seasonally moist to saturated soils, often in disturbed areas. Some populations of Diplachne fusca in southern Asia combine nitrogen-fixation, high salinity tolerance and palatibilty to livestock, which should be pursued with further research for purposes of soil reclamation. Diplachne fusca subsp. uninervia is the most invasive of the subspecies and is becoming weedy in some non-native areas, including in the Old World. This monograph provides detailed descriptions of all taxa, a key to the species and subspecies, geographic distributions and information on the anatomy of leaves, stems, lemmatal micromorphology and discussions of the chromosome numbers. Lectotypes are designated for: Atropis carinata Grisb.; Diplachne acuminata Nash; Diplachne capensis (Nees) Nees var. concinna Nees; Diplachne capensis (Nees) Nees var. obscura Nees, Diplachne capensis (Nees) Nees var. prolifera subvar. minor Nees, Diplachne halei Nash, Diplachne maritima E.P. Bicknel, Diplachne muelleri Benth., Diplachne reverchonii Vasey, Diplachne tectoneticola Backer, Leptochloa imbricata Thurb., Leptochloa neuroglossa Peter, Leptochloa uninervia var. typica fo. abbreviata Parodi, Triodia ambigua R. Br. and Triodia parviflora R. Br.

Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M.romaschenkoi.

A taxonomic treatment, phylogeny based on analysis of six DNA sequence markers (ITS, ndhA intron, rpl32-trnL, rps3, rps16 intron and rps16-trnK) and classification of Muhlenbergia for Peru is given. Seventeen species and one presumed hybrid are recognised. Muhlenbergiaromaschenkoi sp. nov. is newly described from the Río Huallaga Valley, northeast of Huánuco. The type of Podosemumangustatum [≡ Muhlenbergiaangustata] clearly aligns with what we had been referring to as the hybrid between this species and M.rigida. Therefore, we adopt the next available heterotypic name, Muhlenbergiacoerulea, for what we had been calling M.angustata and change the hybrid designation to M.coerulea × M.rigida. Lectotypes are designated for Epicampescoerulea Griseb., Muhlenbergiaaffinis Trin., Muhlenbergiaberlandieri Trin., Muhlenbergiabeyrichiana Kunth, Muhlenbergiaelegansvar.atroviolacea Kuntze, Muhlenbergiaelegansvar.subviridis Kuntze and Muhlenbergiaphragmitoides Griseb.

ResumenBrindamos un tratamiento taxonómico, una filogenia basado en el análisis de seis marcadores de secuencia de ADN (ITS, intrón ndhA, rpl32-trnL, rps3, intrón rps16, rps16-trnK) y la clasificación de Muhlenbergia para Perú. Se reconocen diecisiete especies y un supuesto híbrido. Muhlenbergiaromaschenkoi sp. nov. es descrita como especie nueva procedente del valle de Huallaga, al noreste de Huánuco. El tipo de Podosemumangustatum [≡ Muhlenbergiaangustata] se alinea claramente con lo que nosotros habíamos referido como el híbrido entre esta especie y M.rigida. Por lo tanto, adoptamos el siguiente nombre heterotípico disponible, Muhlenbergiacoerulea para lo que habíamos estado llamando M.angustata, y cambiamos la designación híbrida a M.coerulea × M.rigida. Los lectotipos son designados para Epicampescoerulea Griseb., Muhlenbergiaaffinis Trin., Muhlenbergiaberlandieri Trin., Muhlenbergiabeyrichiana Kunth, Muhlenbergiaelegansvar.atroviolacea Kuntze, Muhlenbergiaelegansvar.subviridis Kuntze y Muhlenbergiaphragmitoides Griseb.

Systematics of disakisperma (poaceae, chloridoideae, chlorideae).

Disakisperma Steud. is a genus of four predominantly perennial C4 (NAD-ME) species in the Americas, Africa, and Asia. Its species previously were treated in Eleusine, Eragrostis, Coelachyrum, Cypholepis, Leptochloa, or Diplachne by nearly all authors.It includes the widespread North and South American amphitropical disjunct Disakisperma dubium (type of the genus), Disakisperma eleusine from southern Africa, Disakisperma obtusiflorum from central and northern Africa to southern Asia, and Disakisperma yemenicum, comb. nov. from eastern and southern Africa to Yemen. This paper provides a key to the species, geographic distributions, descriptions, including comments on the anatomy of leaves, stems, lemmatal micromorphology, a phylogram based on five molecular markers, and discussions of chromosome numbers. The species are rarely, if at all, known outside of their native ranges and are unlikely to become aggressively invasive. All species are considered Least Concern following IUCN guidelines. Lectotypes are designated for Diplachne dubia var. pringleana Kuntze, Disakisperma mexicana Steud., Eragrostis yemenica Schweinf., and Leptochloa appletonii Stapf.

ResumenDisakisperma Steud. es un género de quatro especies perennes C4 (NAD-ME), las cuales que son de las Américas y África y Asia. Sus especies previamente fueron tratados en Eleusine, Eragrostis, Coelachyrum, Cypholepis, Leptochloa, o Diplachne por casi todos los autores. Incluye la generalizada del Norte y América del Sur amfitropical disjunta Disakisperma dubium (tipo del género), Disakisperma eleusine desde el sur de África, Disakisperma obtusiflorum del centro y el norte de África hasta el sur de Asia, y Disakisperma yemenicum, comb. nov. del este y sur África a Yemen. Este documento proporciona una clave para las especies y las descripciones completas, incluidos los comentarios sobre la anatomía de las hojas, tallos, micromorfología lemmatal, una filograma basado en cinco marcadores moleculares y las discusiones de los números de cromosomas. Las especies son raramente, si acaso, conocida fuera de sus áreas de distribución natural y es poco probable para convertirse en invasora agresiva. Todos las epecies se consideran la designación de Least Concern sigue IUCN. Se designa lectotipos para Diplachne dubia var. pringleana Kuntze, Disakisperma mexicana Steud., Eragrostis yemenica Schweinf. y Leptochloa appletonii Stapf.

A phylogeny and classification of the Muhlenbergiinae (Poaceae: Chloridoideae: Cynodonteae) based on plastid and nuclear DNA sequences.

PREMISE OF THE STUDY: To understand the origins of C(4) grasslands, we must have a better interpretation of plant traits via phylogenetic reconstruction. Muhlenbergiinae, the largest subtribe of C(4) grasses in Mexico and the southwestern United States (with 176 species), is taxonomically poorly understood. • METHODS: We conducted a phylogenetic analysis of 47 genera and 174 species using six plastid regions (ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3, and rpl32-trnL) and the nuclear ITS 1 and 2 (ribosomal internal transcribed spacer) regions to infer evolutionary relationships and revise the classification. • KEY RESULTS: In our analyses, Muhlenbergia (ca. 153 species) is paraphyletic, with nine genera (Aegopogon, Bealia, Blepharoneuron, Chaboissaea, Lycurus, Muhlenbergia, Pereilema, Redfieldia, Schaffnerella, and Schedonnardus) found nested within. We recognized the following five well-supported monophyletic lineages within Muhlenbergia: subg. Muhlenbergia, with species that have phosphoenolpyruvate carboxykinase-like leaf anatomy and long, scaly rhizomes; subg. Trichochloa with long-lived species that are relatively tall (up to 3 m); subg. Clomena with 3-nerved upper glumes; sect. Pseudosporobolus species with narrow panicles and plumbeous spikelets; and sect. Bealia species with lemmas with hairy margins and midveins. • CONCLUSIONS: We propose expanding the circumscription of Muhlenbergia to include the other nine genera in this subtribe and make the following new combinations: Muhlenbergia subg. Bealia, M. diandra, M. geminiflora, M. paniculata, M. phleoides, M. subg. Pseudosporobolus (also lectotipified), M. solisii, M. tricholepis. We also propose several new names: M. ammophila, M. columbi, M. plumosa. Our phylograms suggest that Muhlenbergia originated in North America because the sister (Sohnsia filifolia and Scleropogoninae) is composed of predominantly North American species.