A Preliminary Phylogenetic Analysis of the Grass Subfamily Pooideae (Poaceae), with Attention to Structural Features of the Plastid and Nuclear Genomes, Including an Intron Loss in GBSSI

Phylogenetic relationships in the grass family (Poaceae), with specific attention to the internal structure of subfamily Pooideae, are analyzed on the basis of nucleotide sequence variation in plastid-encoded genes (matK, ndhF, ndhH, and rbcL). The resulting phylogenetic hypothesis was examined with attention to the taxonomic distributions of two inversions and an insertion/deletion within ndhF, the absence of intron 10 of the nuclear gene GBSSI (waxy), and positions of the boundaries between the Short Single Copy (SSC) region and the neighboring Inverted Repeat (IR) regions of the plastid genome, relative to the endpoints of ndhF and ndhH, which span these boundaries in some taxa. The PACCAD clade is resolved, and extension of the 3\u27-end of ndhF from the SSC region into the IR region is interpreted as a synapomorphy of this clade. The BEP clade also is resolved, with Ehrhartoideae placed as the sister of a clade in which Bambusoideae and Pooideae are sister groups. The loss of GBSSI intron 10 is interpreted as a synapomorphy of Poeae s.l., which includes the traditionally defined tribes Poeae, Aveneae, and Hainardieae, and the results support a novel set of relationships among the tribes of Pooideae, including the placement of Brachypodieae, Bromeae, Triticeae, and Poeae s.l. within a clade for which a three-nucleotide inversion in ndhF is interpreted as a synapomorphy, while a six-nucleotide inversion in ndhF marks a clade that includes all sampled members of subtribe Aveninae within Poeae s.l

Phylogeny of Poa (Poaceae) Based on trnT–trnF Sequence Data: Major Clades and Basal Relationships

Poa, the largest genus of grasses (Poaceae) with over 500 species, occurs throughout temperate and boreal regions in both hemispheres. A phylogenetic study of Poa based on trnT–trnF chloroplast DNA sequence data is presented focusing on basal relationships, major clades, generic boundaries, and placement of putatively closely related genera. Results support the monophyly of the main lineage of Poa if subgen. Andinae is excluded and Anthochloa, Austrofestuca, Dissanthelium (at least in part), and Eremopoa are included. The main Poa clade and subgen. Andinae resolve within a strongly supported Poinae–Alopecurinae–Miliinae clade (PAM). The subdivision of Poa into five major clades, proposed based on chloroplast restriction site data, is supported by sequence data. The basal-most clade (ArcSyl) comprises Poa subgen. Arctopoa and subgen. Poa sect. Sylvestres, two groups having disparate morphology, but similar cpDNA. The next-diverging clade (BAPO), comprising sects. Bolbophorum, Alpinae, Parodiochloa, and Ochlopoa, is strongly supported and characterized by highly divergent cpDNA. The majority of Poa species and sections form a strongly supported clade comprising major clades SPOSTA, PoM, and HAMBADD. Newly reported in this study is Eremopoa as a distinct lineage positioned between this higher Poa clade and BAPO. A revised infrageneric classification of Poa comprising five subgenera is proposed. Two new subgeneric divisions of Poa are proposed: subgen. Stenopoa for the SPOSTA clade and supersect. Homalopoa for the HAMBADD clade. The monotypic genus Anthochloa is reduced to Poa sect. Anthochloa, and its one species recognized as Poa lepidula

Revisión taxonómica del género Poa L. (Poaceae: Pooideae: Poeae) en Chile

A taxonomic revision of the genus Poa in Chile is given. Forty-two species, 5 subspecies and 5 varieties distributed in 4 subgenera and 16 sections are recognized. Synonyms, bibliographic references, notes on distribution and habitat, distinctive characters, and keys to species and subspecific taxa are provided for each species. The names Poa algida Trin., P. annua L. var. eriolepis E. Desv., P. ariguensis Steud., P. chilensis Trin., P. chrysantha Lindm., P. fuegiana (Hook.f.) Hack. var. involucrata Hack., P. maullinica Phil., and P. yaganica Speg. are lectotypified. A new combination and status is established for P. parviceps Hack. [P. scaberula Hook.f. subsp. parviceps (Hack.) Finot, Giussani & Soreng]. Poa dialystostachya is proposed as a new synonym of the endemic P. paposana.Se entrega una revisión taxonómica del género Poa en Chile. Se reconoce la presencia de 42 especies, 5 subespecies y 5 variedades, distribuidas en 4 subgéneros, 15 secciones y un grupo informal “Punapoa”. Para cada especie se proveen sinónimos, referencias bibliográficas, notas sobre distribución actual y potencial, hábitat, caracteres distintivos y claves para determinar las especies y taxones infraespecíficos. Poa atropidiformis var. patagonica (Parodi) Nicora se registra por primera vez para la flora de Chile. Los nombres Poa algida Trin., P. annua L. var. eriolepis E. Desv., P. ariguensis Steud., P. chilensis Trin., P. chrysantha Lindm., P. fuegiana (Hook.f.) Hack. var. involucrata Hack., P. maullinica Phil., y P. yaganica Speg. son lectotipificados. Se establece una nueva combinación y estatus para P. parviceps Hack. [P. scaberula Hook.f. subsp. parviceps (Hack.) Finot, Giussani & Soreng]. Poa dialystostachya se propone como nuevo sinónimo de la especie endémica P. paposana.Fil: Finot, Víctor L.. Universidad de Concepción; ChileFil: Soreng, Robert J.. National Museum of Natural History; Estados UnidosFil: Giussani, Liliana Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Sabena, Florencia Rocio. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Micologia; ArgentinaFil: Villalobos, Nicolás. Universidad de Concepción; Chil

Systematics and evolution of the needle grasses (Poaceae: Pooideae: Stipeae) based on analysis of multiple chloroplast loci, ITS, and lemma micromorphology

27 p.We conducted a molecular phylogenetic study of the tribe Stipeae using nine plastid DNA sequences (trnK-matK, matK, trnH-psbA, trnL-F, rps3, ndhF, rpl32-trnL, rps16-trnK, rps16 intron), the nuclear ITS DNA regions, and micromorphological characters from the lemma surface. Our large original dataset includes 156 accessions representing 139 species of Stipeae representing all genera currently placed in the tribe. The maximum likelihood and Bayesian analyses of DNA sequences provide strong support for the monophyly of Stipeae; including, in phylogenetic order, Macrochloa as remote sister lineage to all other Stipeae, then a primary stepwise divergence of three deep lineages with a saw-like (SL) lemma epidermal pattern (a plesiomorphic state). The next split is between a lineage (SL1) which bifurcates into separate Eurasian and American clades, and a lineage of three parts; a small Patis (SL2) clade, as sister to Piptatherum s.str. (SL3), and the achnatheroid clade (AC). The AC exhibits a maize-like lemma epidermal pattern throughout. AC consists of a core clade of Austral-Eurasian distribution and a “major American clade” of North and South American distribution. The base chromosome number for Stipeae is somewhat ambiguous but based on our survey it seems most likely to be x = 11 or 12. Our phylogenetic hypothesis supports the recognition of the following genera and groups (listed by region): Eurasia—Achnatherum, “Miliacea group”, “Neotrinia” (monotypic), Orthoraphium (monotypic), Patis (also 1 from North America), Piptatherum s.str., Psammochloa (monotypic), Ptilagrostis, Stipa, “Timouria group”, and Trikeraia; Mediterranean—Ampelodesmos (monotypic), Celtica (monotypic), Macrochloa (monotypic), and “Stipella-Inaequiglumes group”; Australasia —Anemanthele (monotypic), and Austrostipa; North America (NA)—“Eriocoma group”, Hesperostipa, Oryzopsis (monotypic), Piptatheropsis, “Pseudoeriocoma group”, and “Stillmania” (monotypic); South America—Aciachne, Amelichloa (also NA), Anatherostipa (s.str.), Jarava (polyphyletic), Lorenzochloa, Nassella (also NA), Ortachne, Pappostipa (also NA), and Piptochaetium (also NA). Monophyly of Phaenospermateae including Duthieinae is demonstrated, and its inclusion within or treatment as sister to Stipeae is rejected.Peer reviewe

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, Calamagrostis crispifolius and Deschampsia santamartensis, 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. Calamagrostis crispifolius 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). Deschampsia santamartensis is similar to Deschampsia hackelii (=Calamagrostis hackelii) 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 Deschampsia podophora (=Calamagrostis podophora), with the new variety D. podophora var. mutica described and illustrated. Deschampsia podophora var. 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 Deyeuxia macrostachya newly synonymised under C. macrophylla and C. pittieri, C. pubescens and Deyeuxia pubescens newly synonimised under C. planifolia. Lectotypes are designated for Agrostis antoniana, Calamagrostis pisinna, Deyeuxia macrostachya and Deyeuxia sodiroana. 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

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

A worldwide phylogenetic classification of the Poaceae (Gramineae) III: An update

We present an updated worldwide phylogenetic classification of Poaceae with 11 783 species in 12 subfamilies, 7 supertribes, 54 tribes, 5 super subtribes, 109 subtribes, and 789 accepted genera. The subfamilies (in descending order based on the number of species) are Pooideae with 4126 species in 219 genera, 15 tribes, and 34 subtribes; Panicoideae with 3325 species in 242 genera, 14 tribes, and 24 subtribes; Bambusoideae with 1698 species in 136 genera, 3 tribes, and 19 subtribes; Chloridoideae with 1603 species in 121 genera, 5 tribes, and 30 subtribes; Aristidoideae with 367 species in three genera and one tribe; Danthonioideae with 292 species in 19 genera and 1 tribe; Micrairoideae with 192 species in nine genera and three tribes; Oryzoideae with 117 species in 19 genera, 4 tribes, and 2 subtribes; Arundinoideae with 36 species in 14 genera and 3 tribes; Pharoideae with 12 species in three genera and one tribe; Puelioideae with 11 species in two genera and two tribes; and the Anomochlooideae with four species in two genera and two tribes. Two new tribes and 22 new or resurrected subtribes are recognized. Forty-five new (28) and resurrected (17) genera are accepted, and 24 previously accepted genera are placed in synonymy. We also provide an updated list of all accepted genera including common synonyms, genus authors, number of species in each accepted genus, and subfamily affiliation. We propose Locajonoa, a new name and rank with a new combination, L. coerulescens. The following seven new combinations are made in Lorenzochloa: L. bomanii, L. henrardiana, L. mucronata, L. obtusa, L. orurensis, L. rigidiseta, and L. venusta.Fil: Soreng, Robert J.. National Museum of Natural History; Estados UnidosFil: Peterson, Paul M.. National Museum of Natural History; Estados UnidosFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Romaschenko, Konstantin. National Museum of Natural History; Estados UnidosFil: Clark, Lynn G.. IOWA STATE UNIVERSITY (ISU);Fil: Teisher, Jordan K.. No especifíca;Fil: Gillespie, Lynn J.. No especifíca;Fil: Barberá, Patricia. No especifíca;Fil: Welker, Cassiano A. D.. No especifíca;Fil: Kellogg, Elizabeth A.. Donald Danforth Plant Science Center; Estados UnidosFil: Li, De Zhu. No especifíca;Fil: Davidse, Gerrit. No especifíca

MISCELLANEOUS CHROMOSOME NUMBER REPORTS FOR POA (POACEAE) IN NORTH AMERICA

Volume: 21Start Page: 2195End Page: 220

Ipomopsis pinnata (Polemoniaceae) in the United States

Volume: 31Start Page: 189End Page: 19