72 resultados para Botanical varieties
Resumo:
This work is a part of a taxonomic revision of the Neotropical genus Hortia (Rutaceae), where three names (H. colambiana Gleason. H. chocoensis Cuatrec., and H. badinii M. Lisboa ex Groppo) are proposed as synonyms of H. brasiliana Vand. ex DC., and the name H. badinii is here validated. Additionally, another name in the Rutaceae. Dictyoloma peruvianum Plana., is proposed as a synonym of D. vandellianum A. Juss. Notes on the type collection of D. vandellianum are provided.
Resumo:
During taxonomic revision of the genus Hortia Vandelli (Rutaceae), it was necessary to lectotypify the name H. megaphylla Taubert because of the destruction of the holotype at B (luring World War II. This name is also formally synonymized under H. longifolia Spruce ex Engler. The author attribution is changed for H. longifolia Spruce ex Engler, crediting Spruce rather than Bentham.
Resumo:
Premise of the study: The phloem is a plant tissue with a critical role in plant nutrition and signaling. However, little is still known about the evolution of this tissue. In lianas of the Bignoniaceae, two distinct types of phloem coexist: a regular and a variant phloem. The cells associated with these two phloem types are known to be anatomically different; however, it is still unclear what steps were involved in the evolution of such differences. Methods: Here we studied the anatomical development of the regular and variant phloem in representatives of all 21 genera of Bignonieae and used a phylogenetic framework to investigate the timing of changes associated with the evolution of each phloem type. Key results: We found that the variant phloem always appears in a determinate location, between the leaf orthostichies. Furthermore, the variant phloem was mostly occupied by very wide sieve tubes and generally included a higher concentration of fibers, indicating an increase in conduction and mechanical support. On the other hand, the regular phloem included much more parenchyma, more and wider rays, and tiny sieve tubes that resembled terminal sieve tubes from plants with seasonal formation of vascular tissues; these findings suggest reduced conduction and higher storage capacity in the regular phloem. Conclusions: Overall, differences between the regular and variant phloem increased over time, leading to further specialization in conduction in the variant phloem and an increase in storage specialization in the regular phloem.
Resumo:
Following a recent revision of the Ocotea indecora (Schott) Meisn. ex Mez group (Lauraceae), some taxonomic and nomenclatural changes have been made. We present here the resulting synonyms, together with typifications, and one new combination. Seven new synonyms are proposed. The following seven names are lectotypified: Mespilodaphne indecora (Schott) Meisn. var. cannella Meisn.. M. indecora var. intermedia Meisn., M. indecora var. laxa Meisn., indecora var. stricta Meisn., O. complicata (Meisn.) Maz, O. elegans Mez, and O. fasciculata (Nees) Mez. Mespilodaphne leucophloea Nees & Mart, is transferred as O. leacophloea (Nees & Mart.) L. C. S. Assis & Mello-Silva.
Resumo:
Two new species of Ocotea Aubl. (Lauraceae) from the restinga of Brazil are described and illustrated. Ocotea arenicola L. C. S. Assis & Mello-Silva and O. ramosissima L. C. S. Assis & Mello-Silva are discovered from Espirito Santo and Bahia states, respectively. Their diagnostic features are indicated, and their relationships to other Ocotea species are discussed.
Resumo:
A new species of Spiranthera A. St.-Hil. (Rutaceae, Galipeinae) is illustrated and described from Espirito Santo, Brazil. Spiranthera atlantica Pi rani represents the first species record for the genus in the Atlantic Forest of eastern Brazil. The new (axon resembles the Amazonian S. guianensis Sandwith but differs by its smaller, few-flowered inflorescences and by the fruit and leaflet morphology.
Resumo:
The radiation of angiosperms is associated with shifts among pollination modes that are thought to have driven the diversification of floral forms. However, the exact sequence of evolutionary events that led to such great diversity in floral traits is unknown for most plant groups. Here, we characterize the patterns of evolution of individual floral traits and overall floral morphologies in the tribe Bignonieae (Bignoniaceae). We identified 12 discrete traits that are associated with seven floral types previously described for the group and used a penalized likelihood tree of the tribe to reconstruct the ancestral states of those traits at all nodes of the phylogeny of Bignonieae. In addition, evolutionary correlations among traits were conducted using a maximum likelihood approach to test whether the evolution of individual floral traits followed the correlated patterns of evolution expected under the ""pollination syndrome"" concept. The ancestral Bignonieae flower presented an Anemopaegma-type morphology, which was followed by several parallel shifts in floral morphologies. Those shifts occurred through intermediate stages resulting in mixed floral morphologies as well as directly from the Anemopaegma-type morphology to other floral types. Positive and negative evolutionary correlations among traits fit patterns expected under the pollination syndrome perspective, suggesting that interactions between Bignonieae flowers and pollinators likely played important roles in the diversification of the group as a whole.
Resumo:
We describe and illustrate the new species Paepalanthus bonsai Trovo & Sano (Eriocaulaceae, Pacpalanthoideae) from the Espinhaco Range in Minas Gerais, Brazil. This species is placed in Paepalanthus Martius subsect. Dichocladus Ruhland due to its dicholoniously branched stem with rigid linear leaves. The new species is compared with the sympairic and morphologically similar species P. glaziovii Ruhland.
Resumo:
The taxonomic identity in microbial eukaryotes remains an impediment to discussing ecology, biogeography and phylogeny, mainly due to a lack of standards in organism descriptions and few comparative works. The lobose testate amoebae (Arcellinida) present an ideal study system, as progress is severely hindered due to taxonomic confusion. In the present survey, we have examined the morphology, biometry and ecology of 2400 individuals in the genus Arcella Ehrenberg, 1832, collected from the Tiete River in Sao Paulo, Brazil. We then contrasted these new data with 26 previously described species, varieties and forms, looking for consistencies and trying to establish distinct entities. Using a combination of morphology and multivariate statistics we were able to determine 4 distinct taxa (Arcella hemisphaerica, Arcella discoides, Arcella gibbosa and Arcella brasiliensis), each of them encompassing a number of other non-distinct nominal taxa. We describe in detail each of the 4 taxa with notes on ecology and biogeography, and list the indistinguishable names in an effort to make identification and taxonomy in the testate amoebae a more objective and precise exercise by clarifying the taxonomic identity.
Resumo:
Matelea quindecimlobata Farinaccio & W. D. Stevens, a new species of Asclepiadoideae, Apocynaceae, from Amazonas, Brazil, is described and illustrated. The most diagnostic aspect of this new species of Matelea. Aublet s. str. is the lobed, then fimbriate outer margin of the outer corona.
Resumo:
We describe and illustrate the new species Actinocephalus koernickeanus Trovo & F. N. Costa (Eriocaulaceae, Paepalanthoideae) from the Espinhaco Range in Minas Gerais, Brazil, and compare it with the morphologically similar species, Paepalanthus actinocephaloides Silveira and P. barbiger Silveira, both from Espinhaco Range.
Resumo:
Recent studies on South American Hybanthus Jacq. s.l. (Violaceae) revealed the need to select a neotype for the name H. longistylus Schulze-Menz, the holotype of which was destroyed in Berlin during World War II.
Resumo:
Crown rufolepidotus Caruzo & Riina (Euphorbiaceae s. str.), a new species from Colombia, is here described and illustrated. The new species is endemic to an area of lowland secondary forests in Antioquia. Morphological characters indicate that this species belongs to Croton sect. Cleodora (Klotzsch) Baill. due to its arborescent habit, petiolar glands, 15 to 25 stamens, as well as the pistillate flowers with imbricate sepals and multifid styles.
Resumo:
The study of collections from the RB herbarium in Rio de Janeiro. Brazil, allows the lectotypification of three names in the Asteraceae: Baccharis xhoelmeana Teodoro, B. xpaulopolitana Teodoro & W. Hoehne, and B. x wilsoniana Teodoro. Additionally, the name B. lymanii G. M. Barroso ex G. Heiden is validated by the indication of a holotype.
Resumo:
Studies have shown that the radiossensitivity in plants varies depending on the varieties and the propagules used in mutagenic treatment. The purpose of this study was to evaluate the radiossensitivity of two types of propagules (buds and in vitro segments of epicotyl) in `Murcott` tangor, `Thomas` and `Fremont` mandarins and `Rangpur` lime (only in vitro segments of epicotyl) and to compare the gamma-rays sensitivity among propagules and among varieties. The following doses were used: 0, 10, 20, 30, 40 and 50 Gy of gamma-rays. The parameters shoot mortality and shoot height, for experiment of bud irradiation, and number of regenerated shoots per explant and percentage of responsive explants, for experiment of peicotyl segments irradiation were evaluated after 60 days. The mutagenic doses tested in buds caused significant reduction in shoot height of all varieties. In the experiment of irradiation of in vitro segments of epicotyl, only `Murcott` tangor and `Rangpur` lime showed significant reduction in the number of regenerated shoots per explant, due to the increase of mutagen doses. Results indicate that radiossensitivity of in vitro (segments of epicotyl) and in vivo (buds) propagules is variable depending on the variety. Also, in some cases the in vitro propagules are more sensitive, to irradiation and in other cases, there is no differential sensibility.