Littérature scientifique sur le sujet « Semiritmi »

Vernonia monocephala subsp. irwinii is a member of the genus Lessingianthus and is hereby transferred to that genus with a new status and a new name, L. semirii. It differs from L. monocephalus by its subsessile to petiolate (vs. sessile) leaves, largely attenuate (vs. rounded to attenuate) leaf bases, adaxial leaf surfaces drying black (vs. greenish), tomentose to velutinous (vs. villous) abaxial leaf surface and stem indument, and number of florets per head (up to 120 vs. up to 210). Both species are native to provinces of the Cerrado Domain, but they do not occur sympatrically: L. semirii is restricted to the North-eastern floristic province (Bahia, Maranhão, Tocantins and Pará states) and northern portion of the Central-western floristic province (Mato Grosso state), whereas L. monocephalus occurs in Distrito Federal and Goiás states in the Central-western, Central and South-eastern floristic provinces. Lessingianthus semirii is hereby described and illustrated for the first time; a distribution map is provided and affinities of this species are discussed.

Four new species of Vellozia are described and named after people linked to Velloziaceae and Brazilian botany. Vellozia everaldoi, V. giuliettiae, V. semirii and V. strangii are endemic to the Diamantina Plateau in Minas Gerais, Brazil. Vellozia giuliettiae and V. semirii are small species that share characteristics that would assign them to Vellozia sect. Xerophytoides, which include an ericoid habit with no leaf furrows and six stamens. Vellozia everaldoi, although a small, ericoid species, could not be placed in that section because it has conspicuous furrows, although it is considered closely related to species of that section. The fourth species, V. strangii, is a relative large species closely related to V. hatschbachii. Descriptions and illustrations of the species are followed by a discussion of their characteristics and putative relationships.

A new species, Calea arachnoidea, which belongs to Calea sect. Meyeria, is hereby described and illustrated. This species occurs in the Serra Negra region, located in the southern portion of the “Zona da Mata” in the state of Minas Gerais, southeastern Brazil. Calea arachnoidea resembles C. quadrifolia, C. heteropappa and C. semirii, and its relationships with these species are discussed and an identification key for the species of C. sect. Meyeria in the state of Minas Gerais is provided. Additionally, photographs, a distribution map, comments about habitat and conservation status are provided.

Abstract— A new species of Calea belonging to the Calea myrtifolia complex is described. Calea sessilifolia stands out by the unusual herbaceous habit 0.1 to 0.25 m tall and sessile leaves compared with the remaining species of the complex. The new species is related to Calea arachnoidea, C. heteropappa, and C. semirii due the polylength pappus scales, but is easily distinguished by its height 0.1--0.25 m tall (vs. 0.3‐2 m), sessile leaves (vs. petiolate leaves), acrodromous venation (vs. camptodromous or semicraspedodromous), and capitulescence of solitary capitula or rarely a dichasiform cyme and few-branched (vs. branched dichasiform cyme). The new species is described, its taxonomic affinities are discussed, and its main vegetative and reproductive structures are illustrated. In addition, a key for identification and one map with the geographic distribution of the species of Calea bearing polylength pappus scales from Calea myrtifolia complex are provided.

O Parque Estadual Serra dos Martírios/Andorinhas (PESMA), é uma importante área de proteção ambiental, localizada no Sudeste do Pará, é uma região de ecótono, transição entre a Amazônia e o Cerrado brasileiro, além de abrigar importantes sítios arqueológicos. No entanto, a região sofre com ações antrópicas, sendo assim, necessários estudos sobre a composição vegetal da região, a fim de auxiliar na tomada de ações para sua preservação. Asteraceae Bercht. & J. Presl é uma das famílias de vegetais mais expressiva no grupo das plantas com flores (angiospermas), contando com aproximadamente 30.000 espécies distribuídas de forma cosmopolitana. No Brasil, atualmente são registradas 2.205 espécies distribuídas em 326 gêneros, para este grupo. O presente estudo taxonômico analisou material proveniente de espécimes ocorrentes na região. Sendo que, esta pesquisa identificou 29 espécies, distribuídas entre 23 gêneros, com apenas um espécime identificada em nível de tribo (Eupatorieae sp.). Cinco espécies são endêmicas para o Cerrado (Chromolaena ferruginea (Gardner) R.M. King & H. Rob., Eitenia praxelioides R.M.King & H.Rob., Lessingianthus semirii Antar & Loeuille, Lepidaploa remotiflora (Rich.) H. Rob. e Praxelis diffusa Hieron.) e uma espécie endêmica para Amazônia (Aspilia ulei Hieron.). Tais resultados contribuem para maiores conhecimentos acerca da biodiversidade da região, bem como auxiliam em sua preservação.