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1.
The floral biology ofTetrastylis ovalis and its pollination by bats was studied in southeastern Brazil. The flowers ofT. ovalis seem more fitted to bat-pollination than those ofPassiflora mucronata, the other known chiropterophilous passionflower. Two species of bats were observed visiting flowers ofT. ovalis: the phyllostomidsGlossophaga soricina andRhinophylla pumilio. Due to the attributes ofTetrastylis, its presumed primitiveness and a better defined bat-pollination syndrome we suggest that chiropterophily evolved independently in the former genus and inPassiflora.  相似文献   

2.
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 likely evolution of this syndrome by additive steps, effecting a change from head up to head down position of the pollinator, can be traced from the floral structure of the remaining four species of the genus.  相似文献   

3.
Tillandsia carminea is a new, morphologically and ecologically distinct species, related toT. stricta Solander, which occurs in the Serra dos Orgaos near Teresopolis, Brazil. It has been taken forT. rosea Lindley, but new investigations have shown thatT. rosea is a synonym toT. stricta and thatT. carminea is a good and distinct species.
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4.
Aechmea itapoana is a new, conspicuous and distinct species from the coastal sand dune scrub of N.E. Brazil. Its possible relationships within subgenusChevaliera, toA. multiflora andA. rodriguesia are discussed.  相似文献   

5.
Calotropis procera (Asclepiadaceae) grows in Israel under extremely hot climatic conditions. Flower morphology is adapted towards the concealment of nectar, in order to protect it against robbery by ants and from evaporation. Pollinia while being inserted within the stigmatic chamber, are soaked in the liquid nectar which, by its concentration controls pollen germination. Two Carpenter bees (Xylocopa) are the only pollinators and their behavior on flowers is discussed.  相似文献   

6.
Most species of the neotropical genusSiphocampylus are believed to be bird-pollinated. The pollination biology ofSiphocampylus sulfureus was studied in a montane region in SE Brazil. This species has features intermediate between ornithophilous and chiropterophilous syndromes: it presents a striking combination of yellowish flowers with strong odour (chiropterophilous features), and diurnal anthesis and sucrose-dominated nectar (ornithophilous features). Major pollinators were hummingbirds by day, and a phyllostomid bat by night.Siphocampylus sulfureus may be viewed as a recent derivate from the presumed ornithophilous stock within sect.Macrosiphon, and thus benefits from the activity of both diurnal and nocturnal vertebrate pollinators.Dedicated to DrIlse Silberbauer-Gottsberger and Prof. DrGerhard Gottsberger for their pioneer contribution to floral biology in Brazil.  相似文献   

7.
The various classifications of the orchid tribeNeottieae are reviewed and a new classification is proposed that divides the tribe into three subtribes,Neottiinae, Limodorinae, andCephalantherinae, based primarily on characters of the column (gynostemium). A cladistic analysis illustrates that these three subtribes are more closely related to one another than either is to any other group in subfam.Neottioideae, although there are very few apomorphic characters for the tribe. Pollination biology is also discussed showing links between breeding systems and distribution. There is also a possible role between column and labellum morphology and the emergence of a deceptive pollination syndrome from one of reward.  相似文献   

8.
Most members of theOchnaceae possess poricidal anthers that are emptied by pollen collecting bees performing vibrational foraging. In several genera, such asTyleria, Adenarake, and various species ofSauvagesia, however, pollen is released by vibration from the anthers through the porus of a novel structure formed by staminodia. These envelop the androecium and gynoecium. Anthers enclosed in this envelope are often longicidal.  相似文献   

9.
Dynastid scarab beetles are the main or exclusive pollinators ofAnnona spp. with large flowers and wide floral chambers. These nocturnal beetles are attracted by the characteristic odours which are caused by measurable temperature elevation of the flowers up to 10°C or even 15°C above the ambient air temperature. TheAnnona spp. investigated showed different floral rhythms varying from one to three days. The elaborate and wellcoordinated flowering processes, along with floral heating and olfactorial attraction of the night-activeCyclocephala spp., result in a very precise and effective pollination. The floral chamber provides alimentation for the beetles in the form of nutritious food-tissues and pollen and offers a mating place and a well developed shelter against predation and environmental changes. A staggered flowering period and an alternative attraction of different beetle species seems to be more a device for diminishing competition between the cooccurringAnnona spp. than a hybridization barrier.  相似文献   

10.
We report bat visits to the inflorescences of Marcgravia pittieri. The animals were videotaped visiting the nectaries of the inflorescences in short hovering flight. Nectarivorous bats caught in front of the inflorescences were Anoura cultrata and Hylonycteris underwoodi (both Phyllostomidae: Glossophaginae). Furthermore, we provide a short overview on inflorescence architecture within the genus Marcgravia with a special focus on functional morphology in chiropterophilous species.  相似文献   

11.
Four types of floral breeding systems—(i) chasmogamy, (ii) aerial pseudocleistogamy, (iii) subterranean pseudocleistogamy and (iv) obligate subterranean true cleistogamy—are observed in the populations ofVigna minima inhabiting the Western Ghats (India). Five categories of phenotypes are recognized based on the number and kinds of floral breeding systems found in a given individual. The frequencies of different categories of phenotypes not only show intra- and interpopulation variation, but also fluctuate from generation to generation suggesting differences in the genetic structure of populations. This polymorphism in the breeding system of a single species is unique and may be adaptive. Obligate subterranean true cleistogamy and amphicarpy appear to be adaptations to jungle fires and soil erosion.—The flowers are of the flag-blossom type and insect visitors act as tripping agents. The tripping mechanism together with the polymorphic floral breeding system result in a balanced mixture of selfing and outcrossing. Such a recombination system may enhance the fitness ofV. minima which is essentially a colonizing species.  相似文献   

12.
Three co-existing pollination mechanisms are found inUrginea maritima: insect-, wind-, and self-pollination. The flowers exhibit a typical insect-pollination syndrome; they offer abundant exposed nectar as well as pollen. Out of the many different visitors only a few could be regarded as pollinators:Apis mellifera, Polistes gallicus, andVespa orientalis. Wind pollination also occurs and generally is responsible for self-pollination.It is argued that the development of extra wind-pollination accompanied by partial self-incompatibility is an adaptation to increase pollination in an unfavourable season (August–September), when insects are scarce.  相似文献   

13.
Thelymitra epipactoides has a highly variable visual display achieved through polychromatic flowers and variable inflorescence size, bearing between 7 and 31 flowers, which attract foraging polylectic bees. Only bees of the genusNomia were observed carrying pollinia and successfully pollinating the orchid. The genusNomia contains polylectic, pollen gathering species that store pollen in both the crop and scopa on the hind legs. The absence of a reward for the bees indicates the orchid is relying on deception to attract visitors. The relationship of deception to mimicry is discussed. Once on the flower, tactile, visual and possibly olfactory stimuli direct bees to the false anther formed by the voluminous column wings, where morphological adaptations of the flower ensure that the pollinarium is deposited on the gaster of the bee to effect pollination. — The lack of seed set observed on the Victorian coast appears to be due to the absence of pollinators from the heath and grassland communities in which the orchid grows. This may well be a consequence of the reduced number of plants flowering in the community (a result of the elimination of fire at these sites), thus not maintaining a floral community attractive to potential pollinators.  相似文献   

14.
Field observations on pollination in New World species of the genusSarcostemma R. Br. sensuHolm are reported. Morphological and anatomical comparisons of pollinated flowers ofSarcostemma subg.Ceramanthus Kuntze (New World) andSarcostemma subg.Sarcostemma (Old World) are presented.  相似文献   

15.
A new species ofTillandsia is described and discussed in regard to related species.
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16.
Large hovering flies with elongated nectar-feeding mouthparts play an important role in the pollination of South African plants. Here we describe and illustrate the pollination of two long-spurred orchids —Disa oreophila H. Bolus subsp.erecta Linder andBrownleea macroceras Sond. — by the long-proboscid flyProsoeca ganglbaueri Lichtwardt (Nemestrinidae).  相似文献   

17.
Field observations showed that three South African orchid species,Satyrium carneum, S. coriifolium andS. princeps, are pollinated by sunbirds. Foraging sunbirds insert their bills into the labellum chamber of the flowers and suck nectar from the labellum spurs with their tongues. The column overarches the entrance to the labellum and pollinaria become affixed to the upper mandible of the bill. Birds often attempt to remove pollinaria by rubbing their bills against a branch, but are mostly unsuccessful due to the large plate-like viscidia which attach the pollinaria very firmly to the bill. Other modifications for bird pollination in theseSatyrium species may include the red, carmine or orange colour of the flowers, sturdy inflorescence stems used for perching and large amounts of dilute nectar in the spurs. EachSatyrium species was pollinated by several species of sunbird, and despite some differences in flowering time, occasional hybrids occur at a site whereS. carneum andS. coriifolium share the same sunbird pollinators.  相似文献   

18.
Amorphophallus nicolsonianus species nova, with cylindrical or napiform corms, is the only representative of the sect.Rapyogkos in India. All the other hitherto known species of this region have globose or depressed globose corms. The new species is related to some Indochinese species and toA. hildebrandtii ( Engl.)Engl. & Gehrm. from Madagascar.  相似文献   

19.
Didymocarpus geitleri spec. nov. is described from Sungai Pandan, Kuantan distr., Pahang, Peninsular Malaysia. Distinctive features include: leaden-grey leaves with long, erect hairs on the upper side and whitish, campanulate flowers with a long exserted, bright yellow style. The colouring of the latter is caused by densely arranged glands. Together with two yellow blotches in front of the filament insertion, the style apparently acts as an anther (pollen) dummy.The paper and the species is dedicated to my greatly respected teacher of Systematic Botany, Prof. DrLothar Geitler, on the occasion of his 90th birthday.  相似文献   

20.
Psecas chapoda, a neotropical jumping spider strictly associated with the terrestrial bromeliad Bromelia balansae in cerrados and semi-deciduous forests in South America, effectively contributes to plant nutrition and growth. In this study, our goal was to investigate if spider density caused spatial variations in the strength of this spider–plant mutualism. We found a positive significant relationship between spider density and δ15N values for bromeliad leaves in different forest fragments. Open grassland Bromeliads were associated with spiders and had higher δ15N values compared to forest bromeliads. Although forest bromeliads had no association with spiders their total N concentrations were higher. These results suggest that bromeliad nutrition is likely more litter-based in forests and more spider-based in open grasslands. This study is one of the few to show nutrient provisioning and conditionality in a spider–plant system.  相似文献   

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