Search results for "botany"
showing 10 items of 4586 documents
An integrated approach to the study of Hypericum occurring in Sicily
2020
An integrated approach to the study of taxa of the genus Hypericum occurring in Sicily is proposed. The results of morphological, biochemical, and molecular analyses are combined to better assess the relationships between the species investigated and test the suitability of DNA barcoding technique in the discrimination of these taxa. For the name Hypericum aegypticum subsp. webbii (Spach) N. Robson a lectotype is designated. For Hypericum triquetrifolium Turra a lectotype and a supporting epitype are designated. The presence of Hypericum perforatum L. subsp. perforatum is excluded from Sicily and the previous reports have to be referred to H. perforatum subsp. veronense (Schrank) Ces. Hyper…
Phytochemical Investigation of the Labiate Dorystoechas hastata
1988
Abstract Carnosol (11,12-dihydroxyabieta-8,11,13-trien-20-oic acid 20,7-lactone), and rosmanol (7α, 11, 12-trihydroxy-abieta-8, 11, 13-trien-20 oic acid-20, 6-lactone), two abietane diterpenes previously isolated from Rosmarinus officinalis, have been isolated from leaves of Dorystoechas hastata. Luteolin, luteolin-7-glucoside, 6-methoxyluteolin-7-glucoside, caffeic acid and chlorogenic acid have also obtained from the same source. The co-occurrence of carnosol, rosmanol and 6-methoxyluteolin-7-glucoside support the close relationship of these two genera.
<p><strong><em>Diversispora valentina</em></strong><strong> (Diversisporaceae), a new species of arbuscular mycor…
2020
A new arbuscular mycorrhizal fungal species, Diversispora valentina, is described and illustrated. In the field, this species is associated with marine dunes located along the Mediterranean coast in eastern Spain. Spores of D. valentina occurred in sporocarps, in clusters, and singly in the soil or inside the roots of Ammophila arenaria (Poaceae), Elymus farctus (Poaceae), Otanthus maritimus (Asteraceae), and Echinophora spinosa (Apiaceae) in the six locations studied. A single-species culture of D. valentina was obtained using Trifolium repens as a host plant. The small subunit internal transcribed spacer and large subunit (SSU-ITS1-5.8S-ITS2-LSU) nrDNA sequences place the new species in t…
Stipa klimesii (Poaceae), a new species from Western Himalayas (India)
2014
Stipa klimesii sp. nov. from the Western Himalayas (India: Ladakh) and its variety S. klimesii var. pubescens var. nov. are described. The new species is similar to S. roborowskyi but differs by its longer anthecium, longer ligules of vegetative shoots, longer hairs on seta and shorter awns. Stipa klimesii is also similar to S. purpurea, but differs by longer ligules of vegetative shoots, shorter awns, slightly shorter hairs on seta and by the character of the panicle, which is compressed and with straight branches in S. klimesii vs. lax and with flexuous branches in S. purpurea. Epidermal patterns of the lemma in S. klimesii and both above-mentioned species, were examined by scanning elect…
Pollination of four sympatric species ofAngelonia (Scrophulariaceae) by oil-collecting bees in NE. Brazil
1991
The manner whereby the oil-producing bisaccate flowers ofAngelonia (Scrophulariaceae) are pollinated by female oil-collecting bees is reported for the first time. Observations were made in the Caatinga formation of Pernambuco, NE. Brazil, on four synchronopatric species. These differ in sizes and structural details of the corolla, level of flower exposition, and habitat preferences. All legitimate visitors wereCentris spp. (Anthophoridae):Angelonia hirta was mainly pollinated byC. fuscata andA. pubescens byC. hyptidis; A. bisaccata andA. hookeriana shared an unidentified species. Several exomalopsine, tetrapediine and meliponid bees exploit the flowers less descriminately for oil or pollen,…
The perfume flowers ofCyphomandra (Solanaceae): Pollination by euglossine bees, bellows mechanism, osmophores, and volatiles
1993
The perfume syndrome and pollination by fragrance-collecting euglossine bees in the neotropic solanaceous genusCyphomandra was confirmed by field observations. In SE Brazil,C. sciadostylis was visited byEufriesea violaceae, andC. diploconos byEuglossa mandibularis; C. hartwegii was pollinated byEulaema meriana in Costa Rica. The primary attractant, fragrant droplets that ooze from the dorsally bulged connectives, is mopped up by the males with the forebasitarsi. Thereby, the poricidal thecae are inadvertently pushed causing the dry pollen to dust the bee's sternum. The number and direction of the pollen jets are related to pollinator size and stigma structure. The flowers are homogamous, se…
The pollination syndrome ofDeplanchea tetraphylla (Bignoniaceae)
1986
The reproductive structures ofDeplanchea tetraphylla (Bignoniaceae) exhibit a significant number of unusual features: inflorescence with an apical “platform”; flowers yellow, short-tubed, strongly zygomorphic; mouth closed through lateral compression; stamens and style long-exserted, erect or slightly reclined; nectar dark brown, exposed in the spoon-shaped lowermost corolla lobe and apparently acting also as a visual cue. These features suggest a highly elaborate syndrome for bird pollination: the birds (probably lorikeets) perch on the inflorescence platform and bend downwards to take up the exposed nectar, thus touching the exserted anthers and stigmas with the throat or breast. The like…
Gender dimorphism and mycorrhizal symbiosis affect floral visitors and reproductive output in Geranium sylvaticum
2010
1. Arbuscular mycorrhizal (AM) symbiosis has been shown to enhance some plant traits to which pollinators are known to respond. Moreover, in gynodioecious species pollinators prefer hermaphrodite flowers over female ones, but the role of fungal symbiosis in sex-specific pollinator attraction is unknown. 2. We examined how plant gender dimorphism and AM symbiosis affect floral visitors and reproductive output in the gynodioecious plant Geranium sylvaticum. Floral visitors were moni- tored in a common garden experiment using mycorrhizal plants inoculated with either Glomus claroideum or Glomus hoi and in non-mycorrhizal condition. 3. We hypothesized that because of the larger flower display a…
Effects of Inbreeding, Outbreeding, and Supplemental Pollen on the Reproduction of a Hummingbird-pollinated Clonal Amazonian Herb
2010
Understory herbs are an essential part of tropical rain forests, but little is known about factors limiting their reproduction. Many of these herbs are clonal, patchily distributed, and produce large floral displays of nectar-rich 1-d flowers to attract hummingbird pollinators that may transport pollen over long distances. The aim of this study was to investigate the effects of clonality, cross-proximity, and patchy distribution on the reproduction of the hummingbird-pollinated Amazonian herb Heliconia metallica. We experimentally pollinated flowers within populations with self-pollen and with pollen of different diversity, crossed flowers between populations, and added supplemental pollen …
Pollination biology in an endangered rocky mountain toadflax (Linaria cavanillesii)
2013
Knowledge about the reproductive system of species inhabiting rocky habitats is scarce. The reproductive biology (floral biology, experimental pollination, insect visits, inbreeding depression, and seed predation) of the rupicolous Linaria cavanillesii was analyzed under field and experimental conditions. Self-compatibility was revealed by the high fruit set, seed set, and seed mass in the pollination experiment. Furthermore, results disclose that this species does not need insect visitors for seed production since fruit set after autonomous self-pollination was similar to that by hand cross-pollination. Self-offsprings were not affected by a strong degree of inbreeding depression in early …