Systematics of Chusquea section Chusquea, section Swallenochloa, section Verticillatae, and section Serpentes (Poaceae: Bambusoideae)

A classification of the neotropical bamboo genus Chusquea into four sections is proposed, and detailed descriptions of 25 species are presented. Chusquea, comprising approximately 120 species, is restricted to the New World, where it is found from Mexico through Central America, along the Andes to Chile and Argentina, and eastward into Brazil. The aggregate altitudinal range of its species is from sea level to more or less 4,000 m, but the majority of Chusquea species inhabit the lush, misty montane forests of Central and South America. The shrubby, high altitude species with intravaginal branching, formerly segregated as the genus Swallenochloa, are incorporated into Chusquea as section Swallenochloa (14 species). Two other smaller natural subgroups known from lower elevations are formally classified as section Verticillatae (5 species) and section Serpentes (4 species). These three sections are well defined, primarily on morphology of the buds, branches, and foliage leaves. The remainder of Chusquea species are provisionally included in section Chusquea. Anatomical and morphological evidence supporting this classification are presented, and additional comments on cyctology and ecology are included. Preliminary phylogenetic analyses in the form of cladograms are provided for the three well defined sections;From this study a pattern of diversification in the genus has emerged, based on modification of habit and branching. The development of the unique bud complement in Chusquea, which consists of one large central bud, subtended by 2-many smaller, independent subsidiary buds, was a major evolutionary step. Once multiple, independent buds could be produced, almost any combination of bud number and branching pattern became possible, thus permitting extreme variation in vegetative morphology. This potential for vegetative plasticity may account for the extensive speciation that has occurred in Chusquea

Classification and Biogeography of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, and Bambusoideae

Molecular data support Anomochlooideae and Pharoideae as the two most basal extant clades within Poaceae. Anomochlooideae are endemic to the New World and have two tribes and two genera including the widespread Streptochaeteae (3–4 spp.) and the critically endangered Anomochloeae (1 sp.) of coastal Bahia, Brazil. Pharoideae are pantropical with one tribe, three genera, and 14 species; all eight species of Pharus occur only in the New World. Bambusoideae and Ehrhartoideae are sister groups and together form a clade sister to Pooideae, although support for this set of relationships is low. Ehrhartoideae are a worldwide subfamily represented in the New World by three tribes (Ehrharteae [as several introduced species], Oryzeae, and Streptogyneae), eight genera, and 33 species. Bambusoideae, also worldwide, include two tribes, Bambuseae (woody bamboos) and Olyreae (herbaceous bamboos). The native New World members of Bambuseae (21 genera, 359 spp.) are divided into four subtribes (Arundinariinae, Arthrostylidiinae, Chusqueinae, Guaduinae), including the genera Chusquea (136 spp.), Merostachys (46 spp.), Aulonemia (34 spp.), Arthrostylidium (32 spp.), and Guadua (25 spp.). Together they are most diverse in the central and northern Andes and southeastern Brazil (from Santa Catarina to Bahia), with secondary centers of diversity in tropical Mexico, the West Indies, Costa Rica, and the Guayana Highlands of South America, and all (especially Chusquea) have a number of undescribed species especially in the Andes, Guayana Highlands, and mountainous south-eastern Brazil. Olyreae (21 genera, 116–120 spp.) are almost exclusively American and are dominated by Olyra (23 spp.) and Pariana (several to 38 spp.), with one monotypic genus endemic to New Guinea (for which a new subtribe, Buergersiochloinae, is proposed) and with one species (Olyra latifolia) occurring in Africa as well as tropical America

Phylogenetic Relationships Within the Centothecoideae + Panicoideae Clade (Poaceae) Based on ndhF and rpl16 Intron Sequences and Structural Data

The PACCAD clade (Panicoideae, Arundinoideae, Chloridoideae, Centothecoideae, Aristidoideae, Danthonioideae) is well supported in all recent studies of Poaceae. However, phylogenetic relationships within the clade are still unresolved, although several branches are strongly supported. In this study, we focus on the phylogeny of the Centothecoideae + Panicoideae clade, one of the major lineages within the PACCAD clade, and one of the most diverse in the family. Two previously unsampled tribes, Isachneae and Steyermarkochloeae, are included, as are additional taxa of Centothecoideae. Phylogenetic analyses of plastid genome sequences (ndhF gene and rpl16 intron) and structural data show increased support of the centothecoid–panicoid clade, but phylogenetic relationships between the two putative subfamilies remain unresolved. Centothecoideae may be sister to Panicoideae or they may be paraphyletic with respect to Panicoideae, as monophyly of Centothecoideae is weakly supported at best. Polyphyly of Panicoideae is demonstrated as Isachneae and Steyermarkochloeae (only with ndhF) form well-supported clades with Micraira–Eriachne and Chasmanthium, respectively. Polyphyly of Arundinelleae is also confirmed as Danthoniopsis and related genera resolve elsewhere. Centothecoideae, as recently circumscribed, resolve as three strongly supported clades including Danthoniopsis and related genera. Cyperochloa (previously incertae sedis) and arundinoid Spartochloa are sister and fall within the centothecoids with strong support. Centotheceae are polyphyletic and segregate into three major groups. One centothecoid genus, Zeugites, is demonstrably paraphyletic

Géneros de bambúes leñosos (Poaceae: Bambusoideae: Arundinarieae, Bambuseae) de Venezuela

RESUMENSe realizó la descripción morfológica de los 11 géneros de bambúes leñosos nativosy exóticos asilvestrados presentes en Venezuela. Se presentan claves dicotómicas para identificar tanto especímenes vegetativos como fértiles, lista de las especies reportadas para cada género, con información sobre distribución y ecología. La lista fue elaborada a partir de las colecciones de Bambusoideae de los herbarios ISC, MER, MERC y VEN, y complementadacon información de bases de datos, publicaciones periódicas, flórulas y catálogos. Se concluye que Venezuela tiene una diversidad importante de bambúes leñosos, con 67 especies nativas, de las cuales 20 son endémicas (29,9%). Myriocladus, Aulonemia, Merostachysy Rhipidocladum constituyen los géneros con mayor endemismo. Chusquea y Myriocladus representan los géneros más diversos, con 20 y 12 especies, respectivamente. Los géneros con distribución más amplia en el país son Arthrostylidium, Chusquea, Guadua y Rhipidocladum; los géneros Atractantha, Merostachys y Myriocladus presentan distribuciónrestringida, limitada al estado Amazonas para el primero, y Amazonas y Bolívar para los dos últimos.ABSTRACTA morphological description of the 11 genera of woody bamboos reported for Venezuela,including both native and naturalized exotic species was done. Dichotomous keys designed to identify vegetative as well as fertile specimens are proposed. An updated list of the species reported for each genus is also included, with information related to their distributionand ecology. The checklist was elaborated based on the Bambusoideae collections of the herbaria ISC, MER, MERC and VEN, complemented with information obtained from online available taxonomic databases, journal publications, local floras and catalogues. We conclude that Venezuela is noteworthy for its diversity in woody bamboos, with a total of 67 species, of which 20 (29.9%) are endemic. Myriocladus, Aulonemia, Merostachys and Rhipidocladum represent the genera with the largest endemism. Chusquea and Myriocladusstand out as the most diverse genera, with 20 and 12 species, respectively. Arthrostylidium,Chusquea, Guadua and Rhipidocladum represent the genera with broadest distribu80tion range in the country. The distribution of Atractantha, Merostachys and Myriocladus is restricted to Amazonas State for the first genus, and Amazonas and Bolívar, for the last two genera

Phylogenetic Relationships Among the One-Flowered, Determinate Genera of Bambuseae (Poaceae: Bambusoideae)

Bambuseae (woody bamboos), one of two tribes recognized within Bambusoideae (true bamboos), comprise over 90% of the diversity of the subfamily, yet monophyly of the tribe is generally only moderately supported, and phylogenetic relationships within the tribe are poorly understood. In addition, there appears to be some level of conflict between morphological and molecular data within the tribe. We conducted a parsimony analysis of 43 species of Bambuseae, three of Olyreae (herbaceous bamboos), and two outgroup taxa using morphological and plastid rpl16 intron sequence data to (1) further test the monophyly of Bambuseae, (2) test the monophyly of Chusqueinae and Hickelinae (the two one-flowered, determinate subtribes), and (3) examine the apparent conflict between molecular and morphological data sets in the determinate, one-flowered genera of Bambuseae. We recovered a monophyletic Bambusoideae, Bambuseae, Olyreae, and Chusqueinae, although support for Bambuseae remained moderate. Our results suggest that the morphological similarities between Chusqueinae and Hickelinae are homoplasious, but robust resolution of relationships among the major lineages of woody bamboos is still wanting

Evolutionary relationships in Panicoid grasses based on plastome phylogenomics (Panicoideae; Poaceae)

Background: Panicoideae are the second largest subfamily in Poaceae (grass family), with 212 genera and approximately 3316 species. Previous studies have begun to reveal relationships within the subfamily, but largely lack resolution and/or robust support for certain tribal and subtribal groups. This study aims to resolve these relationships, as well as characterize a putative mitochondrial insert in one linage. Results: 35 newly sequenced Panicoideae plastomes were combined in a phylogenomic study with 37 other species: 15 Panicoideae and 22 from outgroups. A robust Panicoideae topology largely congruent with previous studies was obtained, but with some incongruences with previously reported subtribal relationships. A mitochondrial DNA (mtDNA) to plastid DNA (ptDNA) transfer was discovered in the Paspalum lineage. Conclusions: The phylogenomic analysis returned a topology that largely supports previous studies. Five previously recognized subtribes appear on the topology to be non-monophyletic. Additionally, evidence for mtDNA to ptDNA transfer was identified in both Paspalum fimbriatum and P. dilatatum, and suggests a single rare event that took place in a common progenitor. Finally, the framework from this study can guide larger whole plastome sampling to discern the relationships in Cyperochloeae, Steyermarkochloeae, Gynerieae, and other incertae sedis taxa that are weakly supported or unresolved.Fil: Burke, Sean V.. Northern Illinois University; Estados UnidosFil: Wysocki, William P.. Northern Illinois University; 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: Craine, Joseph M.. Jonah Ventures; Estados UnidosFil: Pires, J. Chris. University of Missouri; Estados UnidosFil: Edger, Patrick P.. Michigan State University; Estados UnidosFil: Mayfield Jones, Dustin. Donald Danforth Plant Science Center; Estados UnidosFil: Clark, Lynn G.. Iowa State University; Estados UnidosFil: Kelchner, Scot A.. University of Idaho; Estados UnidosFil: Duvall, Melvin R.. Northern Illinois University; Estados Unido