A happy accident: a novel turfgrass reference genome.

Poa pratensis, commonly known as Kentucky bluegrass, is a popular cool-season grass species used as turf in lawns and recreation areas globally. Despite its substantial economic value, a reference genome had not previously been assembled due to the genome's relatively large size and biological complexity that includes apomixis, polyploidy, and interspecific hybridization. We report here a fortuitous de novo assembly and annotation of a P. pratensis genome. Instead of sequencing the genome of a C4 grass, we accidentally sampled and sequenced tissue from a weedy P. pratensis whose stolon was intertwined with that of the C4 grass. The draft assembly consists of 6.09 Gbp with an N50 scaffold length of 65.1 Mbp, and a total of 118 scaffolds, generated using PacBio long reads and Bionano optical map technology. We annotated 256K gene models and found 58% of the genome to be composed of transposable elements. To demonstrate the applicability of the reference genome, we evaluated population structure and estimated genetic diversity in P. pratensis collected from three North American prairies, two in Manitoba, Canada and one in Colorado, USA. Our results support previous studies that found high genetic diversity and population structure within the species. The reference genome and annotation will be an important resource for turfgrass breeding and study of bluegrasses.

A 313 plastome phylogenomic analysis of Pooideae: Exploring relationships among the largest subfamily of grasses.

In this study, we analyzed 313 plastid genomes (plastomes) of Poaceae with a focus on expanding our current knowledge of relationships among the subfamily Pooideae, which represented over half the dataset (164 representatives). In total, 47 plastomes were sequenced and assembled for this study. This is the largest study of its kind to include plastome-level data, to not only increase sampling at both the taxonomic and molecular levels with the aim of resolving complex and reticulate relationships, but also to analyze the effects of alignment gaps in large-scale analyses, as well as explore divergences in the subfamily with an expanded set of 14 accepted grass fossils for more accurate calibrations and dating. Incorporating broad systematic assessments of Pooideae taxa conducted by authors within the last five years, we produced a robust phylogenomic reconstruction for the subfamily, which included all but two supergeneric taxa (Calothecinae and Duthieeae). We further explored how including alignment gaps in plastome analyses oftentimes can produce incorrect or misinterpretations of complex or reticulate relationships among taxa of Pooideae. This presented itself as consistently changing relationships at specific nodes for different stripping thresholds (percentage-based removal of gaps per alignment column). Our summary recommendation for large-scale genomic plastome datasets is to strip alignment columns of all gaps to increase pairwise identity and reduce errant signal from poly A/T bias. To do this we used the "mask alignment" tool in Geneious software. Finally, we determined an overall divergence age for Pooideae of roughly 84.8 Mya, which is in line with, but slightly older than most recent estimates.

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 records and key to Poa (Pooideae, Poaceae) from the Flora of Southern Africa region and notes on taxa including a diclinous breeding system in Poa binata.

Four species of Poa L. are newly reported for sub-Saharan Africa and southern Africa, Poa compressa L., P. iconia Azn., P. infirma Kunth and P. nemoralis L. This is the first report of P. iconia from Africa. Vouchers at PRE of P. bulbosa L. all belong to var. vivipara Koeler, those of P. iconia belong to var. iconia and the one of P. trivialis L. belongs to var. trivialis. Two subspecies are recognised in P. pratensis L.: subsp. irrigata (Lindm.) H.Lindb. and subsp. pratensis. We also designate a lectotype for P. iconia and second-step lectotype for P. leptoclada Hochst. ex A.Rich. and report the first recording of a diclinous breeding system in P. binata Nees. Our account updates the treatment in Identification Guide to Southern African Grasses (Fish et al. 2015) including a key to the taxa and notes on infrageneric taxonomy, DNA subtypes, ecology, chromosome numbers and breeding systems.

Festuca drakensbergensis (Poaceae): A common new species in the F. caprina complex from the Drakensberg Mountain Centre of Floristic Endemism, southern Africa, with key and notes on taxa in the complex including the overlooked F. exaristata.

We present taxonomic notes on the Festuca caprina complex from southern Africa that includes description and illustration of the new species F. drakensbergensis from the Drakensberg Mountain Centre of Floristic Endemism of South Africa and Lesotho. Festuca drakensbergensis can be differentiated from F. caprina s.l. by forming lax short tufts with extravaginally-branching tillers and lateral-tending cataphyllous shoots or rhizomes present, basal foliage reaching < ½ the length of the culms, with generally shorter leaves and shorter anthers, 0.8-1.6(-1.8) mm long. The species also differs from the overlooked species F. exaristata - currently known from two collections from Lesotho - by its fibrous basal sheaths, usually sharp, keel-like leaf blade midrib, drooping panicle with lightly to densely scabrous pendent panicle branches, longer lemmas, 4.5-5.8 mm long, with awns usually present, 0.5-3 mm long, ovary apices sparsely to densely hairy and anthers 0.8-1.6(-1.8) mm long. Taxonomic notes on the different taxa of the F. caprina complex in southern Africa are also provided, including images, key, and lectotypification of F. caprina var. curvula. This research adds a further two endemic species (F. drakensbergensis and F. exaristata) and two endemic varieties (F. caprina var. irrasa and F. caprina var. macra) to the Drakensberg Mountain Centre of Floristic Endemism.

Agrostis and Podagrostis (Agrostidinae, Poaceae) from páramos of Boyacá, Colombia: synoptic taxonomy including a key to Colombian species.

We present taxonomic notes, including updated species descriptions and images, for the nine species of Agrostis and one species of Podagrostis found in páramos of Departamento Boyacá, Colombia (A. boyacensis, A. breviculmis, A. capillaris, A. foliata, A. cf. imberbis, A. mertensii, A. perennans s.l., A. stolonifera, A. tolucensis, Podagrostis trichodes). Agrostis cf. imberbis, previously known from austral South America, is newly recorded for Colombia, A. capillaris is a new regional record for Boyacá, and the name Agrostis stuebelii is lectotypified. We include keys in English and Spanish to distinguish the 15 species of Agrostis and two species of Podagrostis that are cited as occurring in Colombia.

ResumenSe presentan notas taxonómicas, además de descripciones e imágenes actualizadas, para las nueve especies de Agrostis y una especie de Podagrostis encontradas en los páramos del departamento de Boyacá, Colombia (A. boyacensis, A. breviculmis, A. capillaris, A. foliata, A. cf. imberbis, A. mertensii, A. perennans s.l., A. stolonifera, A. tolucensis, Podagrostis trichodes). Agrostis cf. imberbis previamente conocido de Sudamerica austral, se presenta como un nuevo registro para Colombia y A. capillaris se presenta como un nuevo registro regional para Boyacá con el nombre de Agrostis stuebelii también lectotipificado. Se incluyen claves en inglés y español para distinguir las 15 especies de Agrostis y dos especies de Podagrostis citadas para Colombia.

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.

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 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.

Páramo Calamagrostis s.l. (Poaceae): An updated list and key to the species known or likely to occur in páramos of NW South America and southern Central America including two new species, one new variety and five new records for Colombia.

Calamagrostis (syn. Deyeuxia), as traditionally circumscribed, is one of the most speciose genera from páramo grasslands of northwest South America and southern Central America and often dominates these high-elevation habitats. However, it remains difficult for researchers to accurately identify the species due to a lack of floristic treatments for most of the countries containing páramo, with the distribution of many species still very poorly known. In an effort to ameliorate this, we present an updated list and identification keys in English and Spanish (as electronic appendix) to the species of Calamagrostis s.l. known or likely to occur in the páramos of Peru, Ecuador, Colombia, Venezuela, Costa Rica and Panama. Fifty-four species are accepted, constituting 47 species currently circumscribed in Calamagrostis and seven species recently transferred to Deschampsia. Included within this are two new species, Calamagrostiscrispifolius and Deschampsiasantamartensis, which are described and illustrated. Both new species are found in páramos of the Sierra Nevada de Santa Marta (departamento Magdalena), on the northernmost tip of Colombia, with C.crispifolius also found in the Serrania de Perija on the border with Venezuela. Calamagrostiscrispifolius differs from all other species of Calamagrostis s.l. by the presence of strongly curled, readily deciduous leaf blades, amongst numerous other characteristics including open inflorescences with generally patent branches, small spikelets, (3.5-)4-5.5 mm long, with sessile florets and a rachilla prolongation reaching from 2/3 to almost the apex of the lemma, with short hairs (< 1 mm long). Deschampsiasantamartensis is similar to Deschampsiahackelii (=Calamagrostishackelii) from austral South America but differs by its broad, rigid and erect, strongly conduplicate blades, 1.5-2.5 mm wide when folded, ligules of innovations 0.5-1 mm long, truncate or obtuse, ligules of upper flowering culms 3-4 mm long, broadly shouldered with an attenuate central point, ellipsoid spike-like panicle, 3-5.5 long × 1.5-2.5 cm wide, lemma surfaces moderately to lightly scabrous between the veins, lemma apex acute to muticous, entire, rachilla extension often absent and inside of the floret often with hyaline shiny sinuous trichomes to 1 mm long, emerging from the base of the ovary. We also present a broader circumscription of the common species Deschampsiapodophora (=Calamagrostispodophora), with the new variety D.podophoravar.mutica described and illustrated. Deschampsiapodophoravar.mutica principally differs from var. podophora by florets lacking awns and larger habit i.e. multiple taller culms with longer and wider leaf blades forming tussocks, with inflorescences often held within sheaths. Nomenclatural changes are presented, with Deyeuxiamacrostachya newly synonymised under C.macrophylla and C.pittieri, C.pubescens and Deyeuxiapubescens newly synonimised under C.planifolia. Lectotypes are designated for Agrostisantoniana, Calamagrostispisinna, Deyeuxiamacrostachya and Deyeuxiasodiroana. We also document and give notes on five new records of Calamagrostis for Colombia: C.carchiensis, C.guamanensis, C.heterophylla, C.pisinna and C.rigida.

ResumenCalamagrostis (syn. Deyeuxia), como traditionalmente está delimitado, es uno de los géneros con mayor número de especies registradas para las zonas paramunas de Sudamérica y el sur de Centroamérica, en donde a menudo es un elemento dominante en hábitats de alta montaña tropical. Sin embargo, es aun difícil para investigadores identificar con precisión las especies de este género, principalmente por la falta de tratamientos florísticos para la mayoría de países que contienen páramo, con la distribución de muchas especies todavía poca conocida. Con el fin de realizar un aporte al conocimiento de las gramíneas tropicales, se presenta una lista actualizada de nombres y claves de identificación taxonómica en inglés y español (como appendice electrónico) de las especies de Calamagrostis s.l. conocidas o que probablemente se encuentran en los páramos de Perú, Ecuador, Colombia, Venezuela, Costa Rica y Panamá. Como resultado, 54 especies son aceptadas, de las cuales 47 especies están circunscritas en Calamagrostis y siete especies están recientemente transferidas a Deschampsia. Como novedades taxonómicas, se presentan dos nuevas especies, Calamagrostiscrispifolius y Deschampsiasantamartensis, las cuales están descritas e ilustradas. Estas nuevas especies crecen en páramos de la Sierra Nevada de Santa Marta (departamento de Magdalena), en la punta más al norte de Colombia, con C.crispifolius también presente en la Serranía de Perijá en la frontera con Venezuela. Calamagrostiscrispifolius difiere de las otras especies de Calamagrostis s.l. por la presencia de láminas foliares fuertemente crispadas y fácilmente caducas, entre otras características incluyendo inflorescencias abiertas con ramas generalmente patentes, espiguillas pequeñas, (3.5­)4­5.5 mm long., con antecios sésiles y una prolongación de la raquilla llegando desde 2/3 hasta casi el ápice de la lema, con tricomas cortos (< 1 mm long.). Deschampsiasantamartensis es parecida a Deschampsiahackelii (=Calamagrostishackelii) de Sudamérica austral, pero difiere por sus láminas foliares siendo anchas, rígidas y rectas, y fuertemente conduplicadas, 1.5­2.5 mm de ancho cuando plegada, lígulas de las innovaciones 0.5­1 mm long., truncadas u obtusas, lígulas de la parte superior de las cañas floríferas 3­4 mm long., anchas con un punto central atenuado, panojas elipsoides y espiciforme, 3­5.5 long. × 1.5­2.5 cm de ancho, superficies de las lemas moderada a levemente escabroso entre las venas, ápices de las lemas agudas a múticas, enteras, prolongación de la raquilla a menudo ausente, y la presencia de tricomas hialinos, brillantes, y sinuosos de hasta 1 mm long., los cuales salen de la base del ovario. Por último, se presenta una circunscripción más amplia de la especie común Deschampsiapodophora (=Calamagrostispodophora), con la nueva variedad D.podophoravar.mutica, la cual es descrita e ilustrada. Deschampsiapodophoravar.mutica difiere principalmente de la var. podophora porque en sus antecios las aristas están ausentes, y su hábito es más grande i.e. con múltiples cañas largas con láminas foliares más largas y anchas, con inflorescencias a menudo escondidas dentro de las vainas. Los cambios nomenclaturales que se presentan son Deyeuxiamacrostachya sinonimizada bajo C.macrophylla, y C.pittieri, C.pubescens y Deyeuxiapubescens sinonimizada bajo C.planifolia. Designamos los lectotipos para Agrostisantoniana, Calamagrostispisinna, Deyeuxiamacrostachya y Deyeuxiasodiroana. También documentamos y damos notas de cinco nuevos registros de Calamagrostis para la flora de Colombia: C.carchiensis, C.guamanensis, C.heterophylla, C.pisinna, y C.rigida.

Poa laegaardiana, a new species from Ecuador (Poaceae, Pooideae, Poeae, Poinae).

Poa laegaardianasp. nov., is described and illustrated. The new species was found growing on sandy, volcanic soil in Festuca-Calamagrostis dominated grasslands southwest of Ambato and 2.2 km from Fecundo Vela in Provincia de Bolivar. The new species is morphologically similar to Poa gigantea but differs in having glumes 3/4 to 7/8 as long as the adjacent lemmas, a callus with a sparse, short, dorsal tuft of woolly hairs, culms 50-72 cm tall and spikelets 4.1-4.8 mm long. In addition, we include a key to the narrow-spikelike panicled species of Poa in Ecuador.

ResumenSe describe e ilustra una nueva especie, Poa laegaardianasp. nov. La especie se encontró creciendo en suelo arenoso y volcánico en pastizales dominados por Festuca-Calamagrostis al suroeste de Ambato y a 2.2 km de Fecundo Vela en la Provincia de Bolívar. La nueva especie es morfológicamente similar a Poa gigantea, pero se distinque por glumas ¾ a 7/8 tan larga como los lemmas adyacentes, un callo con un mechón escaso, corto, dorsal de pelos lanosos, culmos de 50­72 cm de altura, y espiguillas 4.1­4.8 mm de largo. Además, incluimos una clave para las especies de Poa con panículas espiciformes de Ecuador.

A 250 plastome phylogeny of the grass family (Poaceae): topological support under different data partitions.

The systematics of grasses has advanced through applications of plastome phylogenomics, although studies have been largely limited to subfamilies or other subgroups of Poaceae. Here we present a plastome phylogenomic analysis of 250 complete plastomes (179 genera) sampled from 44 of the 52 tribes of Poaceae. Plastome sequences were determined from high throughput sequencing libraries and the assemblies represent over 28.7 Mbases of sequence data. Phylogenetic signal was characterized in 14 partitions, including (1) complete plastomes; (2) protein coding regions; (3) noncoding regions; and (4) three loci commonly used in single and multi-gene studies of grasses. Each of the four main partitions was further refined, alternatively including or excluding positively selected codons and also the gaps introduced by the alignment. All 76 protein coding plastome loci were found to be predominantly under purifying selection, but specific codons were found to be under positive selection in 65 loci. The loci that have been widely used in multi-gene phylogenetic studies had among the highest proportions of positively selected codons, suggesting caution in the interpretation of these earlier results. Plastome phylogenomic analyses confirmed the backbone topology for Poaceae with maximum bootstrap support (BP). Among the 14 analyses, 82 clades out of 309 resolved were maximally supported in all trees. Analyses of newly sequenced plastomes were in agreement with current classifications. Five of seven partitions in which alignment gaps were removed retrieved Panicoideae as sister to the remaining PACMAD subfamilies. Alternative topologies were recovered in trees from partitions that included alignment gaps. This suggests that ambiguities in aligning these uncertain regions might introduce a false signal. Resolution of these and other critical branch points in the phylogeny of Poaceae will help to better understand the selective forces that drove the radiation of the BOP and PACMAD clades comprising more than 99.9% of grass diversity.

Molecular phylogenetics of cool-season grasses in the subtribes Agrostidinae, Anthoxanthinae, Aveninae, Brizinae, Calothecinae, Koeleriinae and Phalaridinae (Poaceae, Pooideae, Poeae, Poeae chloroplast group 1).

Circumscriptions of and relationships among many genera and suprageneric taxa of the diverse grass tribe Poeae remain controversial. In an attempt to clarify these, we conducted phylogenetic analyses of >2400 new DNA sequences from two nuclear ribosomal regions (ITS, including internal transcribed spacers 1 and 2 and the 5.8S gene, and the 3'-end of the external transcribed spacer (ETS)) and five plastid regions (matK, trnL-trnF, atpF-atpH, psbK-psbI, psbA-rps19-trnH), and of more than 1000 new and previously published ITS sequences, focused particularly on Poeae chloroplast group 1 and including broad and increased species sampling compared to previous studies. Deep branches in the combined plastid and combined ITS+ETS trees are generally well resolved, the trees are congruent in most aspects, branch support across the trees is stronger than in trees based on only ITS and fewer plastid regions, and there is evidence of conflict between data partitions in some taxa. In plastid trees, a strongly supported clade corresponds to Poeae chloroplast group 1 and includes Agrostidinae p.p., Anthoxanthinae, Aveninae s.str., Brizinae, Koeleriinae (sometimes included in Aveninae s.l.), Phalaridinae and Torreyochloinae. In the ITS+ETS tree, a supported clade includes these same tribes as well as Sesleriinae and Scolochloinae. Aveninae s.str. and Sesleriinae are sister taxa and form a clade with Koeleriinae in the ITS+ETS tree whereas Aveninae s.str. and Koeleriinae form a clade and Sesleriinae is part of Poeae chloroplast group 2 in the plastid tree. All species of Trisetum are part of Koeleriinae, but the genus is polyphyletic. Koeleriinae is divided into two major subclades: one comprises Avellinia, Gaudinia, Koeleria, Rostraria, Trisetaria and Trisetum subg. Trisetum, and the other Calamagrostis/Deyeuxia p.p. (multiple species from Mexico to South America), Peyritschia, Leptophyllochloa, Sphenopholis, Trisetopsis and Trisetum subg. Deschampsioidea. Graphephorum, Trisetum cernuum, T. irazuense and T. macbridei fall in different clades of Koeleriinae in plastid vs. nuclear ribosomal trees, and are likely of hybrid origin. ITS and matK trees identify a third lineage of Koeleriinae corresponding to Trisetum subsect. Sibirica, and affinities of Lagurus ovatus with respect to Aveninae s.str. and Koeleriinae are incongruent in nuclear ribosomal and plastid trees, supporting recognition of Lagurus in its own subtribe. A large clade comprises taxa of Agrostidinae, Brizinae and Calothecinae, but neither Agrostidinae nor Calothecinae are monophyletic as currently circumscribed and affinities of Brizinae differ in plastid and nuclear ribosomal trees. Within this clade, one newly identified lineage comprises Calamagrostis coarctata, Dichelachne, Echinopogon (Agrostidinae p.p.) and Relchela (Calothecinae p.p.), and another comprises Chascolytrum (Calothecinae p.p.) and Deyeuxia effusa (Agrostidinae p.p.). Within Agrostidinae p.p., the type species of Deyeuxia and Calamagrostis s.str. are closely related, supporting classification of Deyeuxia as a synonym of Calamagrostis s.str. Furthermore, the two species of Ammophila are not sister taxa and are nested among different groups of Calamagrostis s.str., supporting their classification in Calamagrostis. Agrostis, Lachnagrostis and Polypogon form a clade and species of each are variously intermixed in plastid and nuclear ribosomal trees. Additionally, all but one species from South America classified in Deyeuxia sect. Stylagrostis resolve in Holcinae p.p. (Deschampsia). The current phylogenetic results support recognition of the latter species in Deschampsia, and we also demonstrate Scribneria is part of this clade. Moreover, Holcinae is not monophyletic in its current circumscription because Deschampsia does not form a clade with Holcus and Vahlodea, which are sister taxa. The results support recognition of Deschampsia in its own subtribe Aristaveninae. Substantial further changes to the classification of these grasses will be needed to produce generic circumscriptions consistent with phylogenetic evidence. The following 15 new combinations are made: Calamagrostis × calammophila, C. breviligulata, C. breviligulata subsp. champlainensis, C. × don-hensonii, Deschampsia aurea, D. bolanderi, D. chrysantha, D. chrysantha var. phalaroides, D. eminens, D. eminens var. fulva, D. eminens var. inclusa, D. hackelii, D. ovata, and D. ovata var. nivalis. D. podophora; the new name Deschampsia parodiana is proposed; the new subtribe Lagurinae is described; and a second-step lectotype is designated for the name Deyeuxia phalaroides.

A revision of Poa subsection Aphanelytrum (Poaceae, Pooideae, Poaeae, Poinae); and a new species, Poa auriculata.

In this study the peculiar Andean grass genus Aphanelytrum, with two species, is reduced to Poa subsect. Aphanelytrum comb. & stat. nov. A third species, Festuca reclinata, is assigned to the subsection, which shows states transitional between a more typical Poa and Aphanelytrum. Poa subgen. Poa supersect. Homalopoa sect. Dioicopoa subsect. Aphanelytrum comb. & stat. nov. is characterized in having stooling perennials with decumbent to spreading culm bases that continuously branch and often root at low to mid-culm nodes, glabrous spikelets with long rachillas 1.2-4.2 mm long, short glumes less than ½ the length of the florets, and lemmas with bifid apexes that are mucronate to short-awned. We provide for the three species taxonomic discussions, morphological and anatomical descriptions, keys, illustrations, and a list of specimens. Also, we provide two new names, Poa hitchcockiana nom. nov. and Poa sanchez-vegae nom. nov., and one new combination, Poa reclinata comb. nov. A new species, Poa auriculata sp. nov. from Peru, not thought to be a member of Poa subsect. Aphanelytrum, is presented. It is the first in the genus with prominent auricles. In addition, we place Poa apiculata in Poa subgen. Poa supersect. Homalopoa sect. Dioicopoa subsect. Tovarochloa comb. & stat. nov.

ResumenEn este estudio el género peculiar de gramíneas andinas Aphanelytrum, representado por dos especias, ha sido reducido a Poa subsecc. Aphanelytrum comb. & stat. nov. Una tercera especie es incluida en la subsección, Festuca reclinata, esta presenta características transicionales entre las especies más típicas de Poa y Aphanelytrum. Poa subgen. Poa supersecc. Homalopoa secc. Dioicopoa subsecc. Aphanelytrum comb. & stat. nov. se caracteriza por incluir plantas perennes, stoloniferas, con los culmos decumbentes o extensos, continuamente ramificados, a menudo enraizados en los nudos basales hasta los intermedios, las espiguillas son glabras con rachillas largas de 1.2­4.2 mm de longitud, las glumas más cortas son de la ½ de longitud de los flósculos y las lemas con los ápices bífidos son mucronadas hasta breve-aristadas. Nosotros proveemos para las tres especias discusiones taxonómicas, descripciones morfológicas y anatómicas, claves, ilustraciones y la lista de las muestras usadas. Tambien, proveemos dos nombres nuevos - Poa hitchcockiananom. nov. y Poa sanchez-vegaenom. nov., y una combinación -Poa reclinatacomb. nov. Una nueva especie - Poa auriculatasp. nov. de Perú es presentada. Esta es la especie primera del género con prominentes aurículas. En adición, transferimos Poa apiculata a Poa subgen. Poa supersecc. Homalopoa secc. Dioicopoa subsecc. Tovarochloa comb. & stat. nov.

An updated checklist and key to the open-panicled species of Poa L. (Poaceae) in Peru including three new species, Poa ramoniana, Poa tayacajaensis, and Poa urubambensis.

We provide an updated checklist and key to the 30 Poa species with open panicles from Peru which includes previously circumscribed Dissanthelium and Aphanelytrum species, new taxon records, and three undescribed species. Poa compressa, Poa grisebachii, and Poa leioclada are recorded from Peru for the first time. A number of species are placed in synonymy: Poa carazensis, Poa ferreyrae and Poa tovarii are synonymized under the name Poa fibrifera; Poa adusta (tentatively) and Poa pilgeri are synonymized under Poa candamoana; Poa superata is synonymized under Poa grisebachii; and Poa paramoensis is synonymized under Poa huancavelicae. Included within this treatment are three new species, Poa ramoniana, Poa tayacajaensis and Poa urubambensis, which are described and illustrated. Poa ramoniana, found growing near lakes in high elevation Puna grasslands of Junín, is similar to a small form of Poa glaberrima, but differs in having rhizomes and growing to only 5 cm tall. Poa tayacajaensis, found from shrublands on Andean slopes of Huancavelica and Huánuco, bears similarities to Poa aequatoriensis but differs in having shorter lemmas which are pubescent between the veins, densely scabrous sheaths with smooth, glabrous throats, and shorter ligules. Poa urubambensis, a common element of the undisturbed Polylepis forest understory of the Cordillera Urubamba, Cusco, is distinct from all other members of open-panicled Poa's by having glabrous lemmas with a smooth and glabrous callus, and notably small anthers. The type material for the name Poa adusta is discussed and a lectotype is selected.

ResúmenAportamos una lista actualizada y una clave para las 30 especies de Poa con panículas abiertas de Perú que incluye las especies de Dissanthelium y Aphanelytrum anteriormente circunscritas, nuevos registros de taxones y tres especies no descritas. Poa compressa, Poa grisebachii, y Poa leioclada se registran para Perú por primera vez. Un número de especies son sinonimizadas: Poa carazensis, Poa ferreyrae y Poa tovarii son sinonimizadas bajo el nombre de Poa fibrifera; Poa adusta (tentativamente) y Poa pilgeri son sinonimizadas bajo el nombre de Poa candamoana; Poa superata es sinonimizada bajo Poa grisebachii; y Poa paramoensis es sinonimizada bajo Poa huancavelicae. Dentro de este tratamiento se incluyen dos especies nuevas, Poa ramoniana, Poa tayacajaensis y Poa urubambensis que a continuación se describen e ilustran. Poa ramoniana, que se encuentra creciendo en pastizales de alta elevación cercanos a lagos en la Puna de Junín, es similar a la forma pequeña de Poa glaberrima, pero se diferencia por tener rizomas y crecer hasta sólo 5 cm de altura. Poa tayacajaensis, que se encuentra en matorrales de las laderas andinas de Huancavelica y Huánuco, tiene un parecido a Poa aequatoriensis, pero se diferencia por tener lemas cortas que son pubescentes entre las venas, vainas densamente escabrosas con suaves gargantas glabras, y lígulas cortas. Poa urubambensis, un elemento común de sotobosque no perturbado de los bosques de Polylepis de la Cordillera Urubamba, Cusco, se distingue de todos los otros miembros de Poa con panícula-abierta por tener lemas glabras con un callo suave y glabro, y sus notables anteras pequeñas. El material tipo del nombre Poa adusta es discutido y un lectotipo es seleccionado.

Breeding system diversification and evolution in American Poa supersect. Homalopoa (Poaceae: Poeae: Poinae).

BACKGROUND AND AIMS: Poa subgenus Poa supersect. Homalopoa has diversified extensively in the Americas. Over half of the species in the supersection are diclinous; most of these are from the New World, while a few are from South-East Asia. Diclinism in Homalopoa can be divided into three main types: gynomonoecism, gynodioecism and dioecism. Here the sampling of species of New World Homalopoa is expanded to date its origin and diversification in North and South America and examine the evolution and origin of the breeding system diversity. METHODS: A total of 124 specimens were included in the matrix, of which 89 are species of Poa supersect. Homalopoa sections Acutifoliae, Anthochloa, Brizoides, Dasypoa, Dioicopoa, Dissanthelium, Homalopoa sensu lato (s.l.), Madropoa and Tovarochloa, and the informal Punapoa group. Bayesian and parsimony analyses were conducted on the data sets based on four markers: the nuclear ribosomal internal tanscribed spacer (ITS) and external transcribed spacer (ETS), and plastid trnT-L and trnL-F. Dating analyses were performed on a reduced Poa matrix and enlarged Poaceae outgroup to utilize fossils as calibration points. A relaxed Bayesian molecular clock method was used. KEY RESULTS: Hermaphroditism appears to be pleisiomorphic in the monophyletic Poa supersect. Homalopoa, which is suggested to have originated in Eurasia 8·4-4·2 million years ago (Mya). The ancestor of Poa supersect. Homalopoa radiated throughout the New World in the Late Miocene-Early Pliocene, with major lineages originating during the Pliocene to Pleistocene (5-2 Mya). Breeding systems are linked to geographic areas, showing an evolutionary pattern associated with different habitats. At least three major pathways from hermaphroditism to diclinism are inferred in New World Homalopoa: two leading to dioecism, one via gynodioecism in South America and another directly from hermaphroditism in North America, a result that needs to be checked with a broader sampling of diclinous species in North America. A third pathway leads from hermaphroditism to gynomonoecism in Andean species of South America, with strictly pistillate species evolving in the highest altitudes. CONCLUSIONS: Divergence dating provides a temporal context to the evolution of breeding systems in New World Poa supersect. Homalopoa The results are consistent with the infrageneric classification in part; monophyletic sections are confirmed, it is proposed to reclassify species of sect. Acutifoliae, Dasypoa and Homalopoa s.l. and it is acknowledged that revision of the infrageneric taxonomy of the gynomonoecious species is needed.

Plastid phylogenomics of the cool-season grass subfamily: clarification of relationships among early-diverging tribes.

Whole plastid genomes are being sequenced rapidly from across the green plant tree of life, and phylogenetic analyses of these are increasing resolution and support for relationships that have varied among or been unresolved in earlier single- and multi-gene studies. Pooideae, the cool-season grass lineage, is the largest of the 12 grass subfamilies and includes important temperate cereals, turf grasses and forage species. Although numerous studies of the phylogeny of the subfamily have been undertaken, relationships among some 'early-diverging' tribes conflict among studies, and some relationships among subtribes of Poeae have not yet been resolved. To address these issues, we newly sequenced 25 whole plastomes, which showed rearrangements typical of Poaceae. These plastomes represent 9 tribes and 11 subtribes of Pooideae, and were analysed with 20 existing plastomes for the subfamily. Maximum likelihood (ML), maximum parsimony (MP) and Bayesian inference (BI) robustly resolve most deep relationships in the subfamily. Complete plastome data provide increased nodal support compared with protein-coding data alone at nodes that are not maximally supported. Following the divergence of Brachyelytrum, Phaenospermateae, Brylkinieae-Meliceae and Ampelodesmeae-Stipeae are the successive sister groups of the rest of the subfamily. Ampelodesmeae are nested within Stipeae in the plastome trees, consistent with its hybrid origin between a phaenospermatoid and a stipoid grass (the maternal parent). The core Pooideae are strongly supported and include Brachypodieae, a Bromeae-Triticeae clade and Poeae. Within Poeae, a novel sister group relationship between Phalaridinae and Torreyochloinae is found, and the relative branching order of this clade and Aveninae, with respect to an Agrostidinae-Brizinae clade, are discordant between MP and ML/BI trees. Maximum likelihood and Bayesian analyses strongly support Airinae and Holcinae as the successive sister groups of a Dactylidinae-Loliinae clade.

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.

Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: new records, re-evaluation of P. ruprechtii, and two new species, P. palmeri and P. wendtii.

A revision and key to the 23 species and eight subspecies of Poa (including Dissanthelium) known to occur in Mexico is provided. All voucher specimens seen are cited for accepted taxa, except Poa annua for which one voucher per state is provided. Taxa not previously known from, or poorly understood in, Mexico are discussed.Poa palmerisp. nov. is endemic to forested slopes of the Sierra Madre Oriental, and we distinguished it from Poa ruprechtii s.s., a species of central Mexico that is here emended to include Poa sharpii (syn. nov.). Poa wendtiisp. nov. is described from the Sierra Santa Rosa in northern Coahuila. Poa tacanae is placed in synonymy in Poa seleri. Poa gymnantha and Poa occidentalis are newly reported for Mexico, and material historically identified as Poa villaroelii areplaced in Poa chamaeclinos.The genus Dissanthelium is considered to belong within Poa, and the Mexican taxa, Dissanthelium calycina subsp. mathewsii and Dissanthelium californicum, are treated as Poa calycina var. mathewsii and Poa thomasii, respectively. Poa subsect. Papillopoasubsect. nov. is erected for Poa mulleri. Lectotypes are designated for Poa conglomerata and Poa seleri.

Migration of endpoints of two genes relative to boundaries between regions of the plastid genome in the grass family (Poaceae).

Overlapping genes occur widely in microorganisms and in some plastid genomes, but unique properties are observed when such genes span the boundaries between single-copy and repeat regions. The termini of ndhH and ndhF, situated near opposite ends of the small single-copy region (SSC) in the plastid genomes of grasses (Poaceae), have migrated repeatedly into and out of the adjacent inverted-repeat regions (IR). The two genes are transcribed in the same direction, and the 5' terminus of ndhH extends into the IR in some species, while the 3' terminus of ndhF extends into the IR in others. When both genes extend into the IR, portions of the genes overlap and are encoded by the same nucleotide positions. Fine-scale mapping of the SSC-IR junctions across a sample of 92 grasses and outgroups, integrated into a phylogenetic analysis, indicates that the earliest grasses resembled the related taxa Joinvillea (Joinvilleaceae) and Ecdeiocolea (Ecdeiocoleaceae), with ca. 180 nucleotides of ndhH extending into the IR, and with ndhF confined to the SSC. This structure is maintained in early-diverging grass lineages and in most species of the BEP clade. In the PACMAD clade, ndhH lies completely or nearly completely within the SSC, and ca. 20 nucleotides of ndhF extend into the IR. The nucleotide substitution rate has increased in the PACMAD clade in the portion of ndhH that has migrated into the SSC.