A new species of Paspalum, Notata group (Poaceae, Paspaleae), from the Cerrado biome, Brazil: description, chromosome number, and leaf blade anatomy
(original) (raw)Related papers
Plant Systematics and Evolution, 2015
Paspalum schesslii, a new species from the state of Mato Grosso in central-western Brazil, is described and illustrated. The new species is related to P. malmeanum, from central-western Brazil and eastern Bolivia, and Paspalum eucomum, from central Brazil. It comprises shorter plants with leaf blades and racemes shorter than those of the related species, and spikelets having obovate, deciduous upper florets. An unexpected chromosome number 2n = 12 was found in specimens of P. schesslii; thus it differs from both P. malmeanum, which has 2n = 20, and P. eucomum, for which 2n = 30 and 2n = 32 chromosome counts are here reported for the first time. The discovery of a new species having 2n = 12, which often cohabits with diploid populations of the widespread related species, P. stellatum, is consistent with an hypothesis about the hybrid origin of the polyploid cytotypes of P. stellatum having 2n = 32 and 2n = 52 chromosomes. Moreover, such an hybrid origin involving parental species with different base chromosome numbers (x = 6 and x = 10) could also explain the occurrence of 32 chromosomes in P. eucomum, potentially documenting a speciation mechanism that is otherwise unknown in the genus.
Four New Species of Paspalum (Poaceae, Paniceae) from Central Brazil, and Resurrection of an Old One
Systematic Botany, 2008
Four new Brazilian species from the genus Paspalum are described and illustrated: P. phaeotrichum, P. vexillarium, P. veredense, and P. clipeum. Paspalum phaeotrichum is an annual with no obvious affinity to any known species of Paspalum, although it shares several characters with species of both P. subg. Ceresia and the 'Bertoniana' group. Paspalum vexillarium is presumably related to P. ceresia, with which it has been confused. Paspalum veredense shows affinities with both P. ellipticum and P. erianthoides. Paspalum clipeum is probably related to annual species of the 'Plicatula' group, although it lacks the dark brown upper florets typical of that group. Moreover, P. spissum, a species currently considered as a synonym under P. carinatum, is recognized on the basis of vegetative morphology, phenology and habitat. Keys to the treated species are provided when relevant, as well as a distribution map. Resumo-Quatro novas espécies de Paspalum do Brasil são descritas e ilustradas: P. phaeotrichum, P. vexillarium, P. veredense, e P. clipeum. Paspalum phaeotrichum é uma espécie anual sem afinidades obvias com outras espécies do gênero, embora compartilhe vários caracteres com P. subg. Ceresia e com o grupo 'Bertoniana'. Paspalum vexillarium é supostamente relacionada a P. ceresia, com a qual tem sido confundida. Paspalum veredense tem afinidades com P. ellipticum e P. erianthoides. Paspalum clipeum é provavelmente relacionada às espécies anuais do grupo 'Plicatula', embora não apresente os antécios superiores de cor marrom escura, típicos desse grupo. Além disso, P. spissum, uma espécie atualmente considerada como sinônimo de P. carinatum, é reabilitada com base na morfologia vegetativa, fenologia e habitat. São fornecidas chaves para as espécies tratadas, quando relevante, assim como um mapa de distribuição.
Four New Species of Paspalum (Poaceae, Paniceae) from Central Brazil, and Resurrection of an Old One
Systematic Botany, 2008
Four new Brazilian species from the genus Paspalum are described and illustrated: P. phaeotrichum, P. vexillarium, P. veredense, and P. clipeum. Paspalum phaeotrichum is an annual with no obvious affinity to any known species of Paspalum, although it shares several characters with species of both P. subg. Ceresia and the 'Bertoniana' group. Paspalum vexillarium is presumably related to P. ceresia, with which it has been confused. Paspalum veredense shows affinities with both P. ellipticum and P. erianthoides. Paspalum clipeum is probably related to annual species of the 'Plicatula' group, although it lacks the dark brown upper florets typical of that group. Moreover, P. spissum, a species currently considered as a synonym under P. carinatum, is recognized on the basis of vegetative morphology, phenology and habitat. Keys to the treated species are provided when relevant, as well as a distribution map. Resumo-Quatro novas espécies de Paspalum do Brasil são descritas e ilustradas: P. phaeotrichum, P. vexillarium, P. veredense, e P. clipeum. Paspalum phaeotrichum é uma espécie anual sem afinidades obvias com outras espécies do gênero, embora compartilhe vários caracteres com P. subg. Ceresia e com o grupo 'Bertoniana'. Paspalum vexillarium é supostamente relacionada a P. ceresia, com a qual tem sido confundida. Paspalum veredense tem afinidades com P. ellipticum e P. erianthoides. Paspalum clipeum é provavelmente relacionada às espécies anuais do grupo 'Plicatula', embora não apresente os antécios superiores de cor marrom escura, típicos desse grupo. Além disso, P. spissum, uma espécie atualmente considerada como sinônimo de P. carinatum, é reabilitada com base na morfologia vegetativa, fenologia e habitat. São fornecidas chaves para as espécies tratadas, quando relevante, assim como um mapa de distribuição.
Paspalum chilense (Poaceae, Paspaleae): A new species from southern South America
Paspalum chilense, a new species from Chile belonging to the informal Notata group, is described and illustrated on the basis of morphological, cytological and molecular evidence. Our evidence supports its affinity with P. barretoi and P. nummularium, from Brazil, from which it probably diverged by vicariant speciation. The limited available material of the new species was previously identified as P. pumilum or P. minus. A new key to the species of the core Notata group is provided.
Paspalum chilense (Poaceae, Paspaleae): A new species from southern South America
Phytotaxa, 2015
Paspalum chilense, a new species from Chile belonging to the informal Notata group, is described and illustrated on the basis of morphological, cytological and molecular evidence. Our evidence supports its affinity with P. barretoi and P. nummularium, from Brazil, from which it probably diverged by vicariant speciation. The limited available material of the new species was previously identified as P. pumilum or P. minus. A new key to the species of the core Notata group is provided.
A New Species of Paspalum (Poaceae, Paniceae) from Central Brazil
Systematic Botany, 2005
Paspalum vallsii, a new species in Paspalum sect. Pectinata from cerrado areas of central Brazil, is described and illustrated. It is most similar to P. reticulinerve, from which it differs by having solitary, longer spikelets with the upper glume and the lower lemma glabrous. It differs also from P. imbricatum and P. aspidiotes by having a narrower rachis. A key to the species of Paspalum sect. Pectinata is provided. RESUMO. Paspalum vallsii, uma nova espécie de Paspalum sect. Pectinata da região do cerrado do Brasil central, é descrita e ilustrada. A espécie é relacionada a P. reticulinerve, da qual difere pelas espiguetas mais longas e solitárias e pela gluma superior e lema inferior glabros. Difere de P. imbricatum e P. aspidiotes pela raquis mais estreita. É fornecida uma chave para todas as espécies de Paspalum sect. Pectinata.
Phytotaxa, 2018
A new species, Paspalum cangarum, morphologically similar to P. brachytrichum, is described. While both occur in canga vegetation, P. brachytrichum is endemic to the state of Minas Gerais and the new species is restricted to the Serra dos Carajás, state of Pará, Brazil. These species can be distinguished from each other mainly by their height, length and number of racemes and by the lengths of their pedicels and spikelets.
A Preliminary Approach to the Phylogeny of the Genus Paspalum (Poaceae)
Genetica, 2006
The present work intends to clarify the phylogenetic relationships among the species of Paspalum L. belonging to the informal groups Notata/Linearia and Dilatata, and to raise some preliminary hypotheses on the phylogeny of the genus as a whole. A combined dataset including morphological and molecular characters was used to analyze 28 species of Paspalum plus some representatives of related genera of the tribe Paniceae. Analyses were performed using both parsimony and maximum likelihood. The monophyly of Paspalum is not supported nor contradicted. The circumscription of informal groups of Paspalum is discussed, as well as the cladistic treatment of allopolyploid taxa, especially those comprising the Dilatata group. The relationships of members of the Dilatata with their putative progenitors is confirmed, but the monophyly of the group as a whole is not. A close relationship between P. dilatatum Poir. and P. lividum Trin. ex Schltdl. is shown. Our analysis is consistent with the monophyly of a group comprising Notata+Linearia, with a monophyletic Notata group nested within it. The delimitation of the core Notata is proposed by including P. conduplicatum Canto-Dorow, Valls and Longhi-Wagner, P. notatum Flüggé, P. minus E. Fourn., P. pumilum Nees and P. subciliatum Chase.