Topic
Oxandra
About: Oxandra is a research topic. Over the lifetime, 18 publications have been published within this topic receiving 162 citations.
Papers
TL;DR: It is speculated that the stamens of these species could maintain their original laminar form with tongue-shaped prolongations because of the low selection pressure exerted by the non-destructive thrips and staphylinid beetles.
Abstract: The Central Amazonian Annonaceae species Bocageopsis multiflora and Oxandra euneura were studied with respect to anthesis, flowering phenology, odor production, and visitation and pollination of the flowers by insects. Flowers of both species are protogynous and have diurnal anthesis. The sweetish flower odors attract thrips to Bocageopsis flowers and staphylinid beetles and thrips to Oxandra flowers. These insects apparently are not harmful to flower tissues; they crawl on the stamens and stigmas and seem to be efficient pollen vectors. The stamens of Bocageopsis and Oxandra, which possess a prominent tongue-shaped connective prolongation supposedly represent the archaic stamen form within the Annonaceae. It is speculated that the stamens of these species could maintain their original laminar form with tongue-shaped prolongations because of the low selection pressure exerted by the non-destructive thrips and staphylinid beetles. The strong influence of voracious beetles on flower structures in other neotropical Annonaceae is discussed.
Duas especies de Annonaceae que ocorrem na Amazǒnia Central, Bocageopsis multiflora e Oxandra euneura, foram investigadas com relacao a antese, producao de odor, insetos visitantes e potenciais polinizadores e tambem sua fenologia. As duas especies sao protoginas, tem antese diurna e produzem um odor perfumado que atrai trips as flores de Bocageopsis e coleopteros Staphylinidae e trips as flores de Oxandra. Estes insetos aparantemento nao causam danos as flores, se movimentam entre os estames e sobre os estigmas e parecem ser eficientes no transporte do polen. Os estames de Bocageopsis e Oxandra com conectivo liguliforme prolongado supostamente representam a forma de estames mais arcaicos dentro das Annonaceae. Especula-se que os estames destas especies poderiam ter mantido sua forma laminar original com conectivo liguliforme prolongado, em razao da fraca pressao seletiva exercida por insetos nao destrutivos como os trips e os Staphylinidae. A forte influencia dos coleopteros mais vorazes sobre as estruturas florais de outras Annonaceae neotropicais e discutida.
41 citations
TL;DR: A new triterpenoid derived from 24-methylcycloartanol was isolated from the leaves of Oxandra cf.
Abstract: A new triterpenoid (1) derived from 24-methylcycloartanol was isolated from the leaves of Oxandra cf. xylopioides. An unusual structure of the new compound was assigned as 1, for which the name berenjenol is proposed, on the basis of the spectroscopic data of the natural product and of its derivatives 2 and 3. The leaves also afforded the known monoterpene isoespintanol (4). Compounds 1 and 4 significantly reduced the paw edema induced by carrageenan by 64% and 43%, at 3 h, respectively. Moreover, 4 reduced IL-1β production by 72% at 100 μM and reduced IL-1β mRNA synthesis.
36 citations
TL;DR: The structures of urabaine, N -methyhlurabaine and N,N′ -dimethylurabain, three new 7,7′-bisdehydroaporphine alkaloids from Oxandra cf. major, have been elucidated by spectroscopic analysis and synthesis as mentioned in this paper.
36 citations
TL;DR: Three biogenetic hypotheses are discussed in the light of the structures of the azafluorenones found to date in the Annonaceae.
35 citations
TL;DR: A taxonomic revision is given of the Neotropical genus Oxandra (Annonaceae).
Abstract: A taxonomic revision is given of the Neotropical genus Oxandra (Annonaceae). Within the genus 27 species are recognized, 4 of which are new to science. Most of the species are occurring in tropical South America, whereas a few (6) are found in Mexico and Central America and two in the West Indies (Greater and Lesser Antilles). A key to all species is provided. The treatment includes chapters about the history of the genus and morphology. All species are fully described, including full synonymy, notes on distribution and ecology, field observations (when available), vernacular names (when given), and mostly short notes about relationships of the species concerned. For each species a distribution map is made. At the end of the revision a complete list of vernacular names is included.
11 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2016 | 1 |
| 2015 | 1 |
| 2014 | 2 |
| 2013 | 2 |
| 2008 | 2 |