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1.
Pedro Fiaschi 《Brittonia》2005,57(3):240-247
Three new species of BrazilianDendropanax from the rain forests of Bahia state are described and illustrated.Dendropanax amorimii, endemic to the rain forests near Boa Nova, in southern Bahia, is characterized by compound umbellate inflorescences with elongated primary branches each having a proximal whorl of bracts, and by leaves with well-developed tertiary venation.Dendropanax bahiensis, endemic to the Atlantic rain forests of southern Bahia, is distinguished by its large and membranous leaves with reddish schizogenous glands on the abaxial surface and by the reduced and branched inflorescences with short-pedicellate flowers and large fruits.Dendropanax geniculatus, an endemic species from the “matas de grotão” of Serra da Chapadinha, Chapada Diamantina, is characterized by simple and usually geniculate inflorescences bearing long-pedicellate flowers and fruits.  相似文献   

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3.
Myristica fatua is a dioecious specialist species restricted to the endangered, freshwater Myristica swamp forests in the Western Ghats, India. Earlier studies have alluded to pollination by deception in members of the Myristica genus, and thus we examined the pollination ecology comprising floral biology, flower production, flower visitors, and reproductive success in M. fatua and inferred the potential strategies that could permit such deception in this habitat specialist tree. Male flowers provide pollen rewards for an extended period of time while female flowers are rewardless and both sexes are visited by generalist insects, mainly by honeybees and stingless bees. Bee visits were significantly more frequent and longer on male than on female flowers as bees collected pollen from male flowers. We found that flower production patterns create a preponderance of males compared to females in the swamp populations. Using a model of honeybee color vision, we found the distance between the color loci of male and female flowers and based on minimum visual angle subtended by these flowers, we suggest that the two floral sexes cannot be discriminated by bees. Bees are likely deceived by the perceptual similarity of rewardless female flowers to pollen-offering male flowers and pollination is the consequence of foraging errors made by pollinators that encounter largely male–rarely female flower mosaics as they forage among clump-distributed M. fatua trees in the swamp habitat.  相似文献   

4.
Rafael Lira  Michael Nee 《Brittonia》1999,51(2):204-209
Sechium mexicanum is described as a new species ofSechium sect.Frantzia. It differs from the remaining species of the section by several features of the inflorescences and staminate flowers, the obovoid and completely unarmed fruits, and pollen grains with 9–10 narrow, poorly defined colpi. It is endemic to Mexico and the first member of sect.Frantzia to be recorded outside of Central America. It grows at 900–2300 m in mesophilous forests and in oak and pineoak forests in the states of Hidalgo, Puebla, Querétaro, and Veracruz.  相似文献   

5.
New chloranthaceous floral structures from the Late Cretaceous (Late Santonian/Early Campanian) of Scania, southern Sweden, have provided important new information on theChloranthistemon plants. The material includes well preserved fragments of inflorescence axes with flowers in situ documenting thatChloranthistemon flowers were bisexual and closely resembled those of extantChloranthus (Chloranthaceae). An emended diagnosis is given for the type species of the genus,Chloranthistemon endressii, and a new species,C. alatus, is described. The flowers ofChloranthistemon are small, perianthless and strongly zygomorphic, consisting of a tripartite and broadened androecium borne in an abaxial to lateral position on the monocarpellate ovary, and arranged in the axils of decussate bracts. Stamens are either completely free (C. alatus), or free at the base and coherent at the apex (C. endressii). The apical connective is extensive in both species; elaborated into conspicuous wing-like structures inC. alatus, or into a massive and shield-like structure inC. endressii. Pollen grains ofC. endressii are spheroidal, and reticulate and spiraperturate, while those ofC. alatus are ellipsoidal, tectate and foveolate with a unique combination of a distal colpus and a proximal furrow (colpus?) perpendicular to each other. Ovaries observed in well preserved flowers of both species are small and undifferentiated. Larger, dispersed fruits of chloranthaceous affinity are abundant and distinct, and probably represent at least two or three species, but cannot be linked with certainty to any of theChloranthistemon species described here.  相似文献   

6.
Bumble bees pollinate and forage on flowers of crop and wild plants in agricultural landscapes. These interactions may depend on landscape patterns and bumble bee traits. We studied the abundance, colony density, and foraging range in long-tongued Bombus diversus Smith and short-tongued B. hypocrita Pérez, and evaluated their visits to flowers of wild plants and cultivated kabocha squash (Cucurbita maxima Duchesne). In forests in a farmland, B. hypocrita workers were trapped more frequently in the canopy. Full-sibs determined by nuclear microsatellite genotypes among workers collected in the farmland showed higher colony density and a larger foraging radius in B. hypocrita (30.8 km?2 and 848 m) than in B. diversus (8.3 km?2 and 723 m), respectively. Regarding wild plants, workers more frequently visited shallow flowers in B. hypocrita and deep flowers in B. diversus. These results suggest that bumble bees with different traits forage on different wild flowers in different habitats. Squash flowers were visited by both bumble bee species at similar frequency in the latter period of colony growth when males and new queens appeared. Composition of full-sib workers visiting squash and wild flowers did not depend on the number of collected workers of individual colonies, indicating that foraging on squash flowers was not associated with colony growth. Thus, growth and reproduction of bumble bee colonies may be supported by various wild plants and cultivated squash, respectively.  相似文献   

7.
Pedro Fiaschi 《Brittonia》2004,56(4):357-360
Schefflera aurata, a new species of Araliaceae endemic to the restinga forests of southern Bahia, Brazil, is described and illustrated. It is probably related toS. morototoni, but can be distinguished by leaflets with strongly coriaceous blades, cuspidate apices, goldensericeous indument of the abaxial surfaces, partial inflorescences with 8–12 subsessile flowers, elongated ovaries, and distinctly larger fruits.  相似文献   

8.
The third species of the genus Pezothrips Karny, P. brunicornis Mirab-balou et Tong, is recorded for the first time from Iran. It was collected on flowers of Dianthus macranthoides in the Dalab forests in Manesht and Ghelarang protected area, northeastern part of Ilam Province.  相似文献   

9.
Diet of Southern Muriquis in Continuous Brazilian Atlantic Forest   总被引:1,自引:0,他引:1  
We systematically collected data on feeding behavior for one group of 33–39 southern muriquis (Brachyteles arachnoides) in Parque Estadual Carlos Botelho (PECB), São Paulo State, Brazil (37,432.45 ha of continuous Atlantic Forest), between January and December 1995. We determined food item consumption from instantaneous scans of behavior. Fruits were the most eaten food items in all 12 mo (40–80% of scan in every mo, average = 71.3%). Muriquis ate young leaves more than mature leaves or flowers. Our results are consistent with previous findings at the same and neighboring forest sites that southern muriquis have a consistently frugivorous diet when inhabiting less disturbed habitats, but contrast with previous observations on oppportunistic frugivory in muriqui populations inhabiting fragmented forests. Sustained high levels of frugivory probably result from year-round availability of fruit within large continuous forests.  相似文献   

10.
The floral biology ofTricyrtis latifolia was investigated at four sites: Nigorigo, Kurumijima and Hikagedaira-san, Gifu Prefecture, and Jöge, Miyagi Prefecture. The flowers open fully by 3 a.m., and anthesis begins at about 8 a.m. Most pollen is taken away by bumblebees by 10 a.m. The distal parts of the trifid style-branches (each branch is further bifid) and the immature stigmata are above the anthers in the first day flowers. The distal parts of the style-branches with their extension curve downward and are positioned under the anthers on the morning of the second day and the stigmata are fully matured. The flowers wilt by the third day. The primary pollinators ofT. latifolia wereBombus diversus andB. honshuensis in three sites; only the former was a primary pollinator at the Jōge site. Bees forage the first and second day flowers, and their backs contact the anthers and stigmata of the second day flowers while the bees are sucking nectar. Breeding experiments showed thatT. latifolia was fairly self-compatible. The avoidance of autogamy and the possibility of geitonogamy are discussed.  相似文献   

11.
Two new species of Miconia from Bolivia are described: Miconia galeiformis and Miconia neei. Both species occur in Andean montane forests. Miconia galeiformis (sect. Chaenopleura) is distinctive within Miconia due to the presence of setose stems, petioles and abaxial leaf surface, and a large, globose stigma. Miconia neei bears unisexual flowers, and can be distinguished from similar species of Miconia sect. Cremanium in Bolivia based on the furfuraceous stems and young nodes, in addition to serrulate leaf margins. The documentation of dioecy in Miconia neei and the occasional occurrence of unisexual flowers in Miconia galeiformis adds to our burgeoning understanding of complex breeding systems within Miconia.  相似文献   

12.
Croton churutensis is described as a new species ofCroton sectionCyclostigma endemic to lowland deciduous forests in coastal Ecuador. Its red latex is used locally in Guayas Province to treat wounds, stomach ulcers, and some skin conditions caused by fungal infections. The new species differs from its closest apparent relative,Croton hibiscifolius, in its arching-pendent inflorescences, short-pedicellate female flowers with quadrifid stigmas, more numerous stamens, laciniate stipules, and lower elevation habitat.  相似文献   

13.
Background and Aims Distyly is a floral polymorphism characterized by the presence of two discrete morphs with reciprocal positioning of anthers and stigmas in flowers on different plants within the same population. Although reciprocal herkogamy and associated floral traits are generally thought to be discrete and strict polymorphisms, little is known about variation in floral traits related to the distylous syndrome within and among populations of a single species. In this study, variation in floral morphology and reciprocal positioning of the sexual organs in the distylous Primula veris (cowslip) is quantified.Methods Data were collected in ten populations occurring in two contrasting habitat types (grasslands and forests), and for each population the average level of reciprocity was assessed, the strength of the self-incompatibility system was determined, and seed production under natural conditions was quantified.Results In grassland populations, flowers showed clear distyly with low and symmetric reciprocity indices at both the lower and upper level. In forests, P. veris produced larger flowers that showed strong deviations in stigma–anther separation, especially in the L-morph. This deviation was mainly driven by variation in stigma height, resulting in high and asymmetric reciprocity indices and the occurrence of several short-styled homostylous plants. Self-incompatibility was, however, strict in both habitats, and morph ratios did not differ significantly from isoplethy. The observed shift in reciprocity in forest populations was associated with a significant reduction in seed production in the L-morph.Conclusions The results indicate that populations of P. veris show habitat-specific variation in flower morphology. Deviations from perfect reciprocal positioning of stigmas and anthers also translate into reduced seed production, suggesting that small changes in sexual organ reciprocity can have far-reaching ecological and evolutionary implications.  相似文献   

14.
Discocarpus pedicellatus, a new species from semideciduous forests of southern Bahia, is here described and illustrated. Pistillate flowers with pedicels 8–10 mm long and styles usually connate into a column 2.5–3 mm long are diagnostic for this species.  相似文献   

15.

Background and Aims

The distribution and differentiation times of flowers in monoecious wind-pollinated plants are fundamental for the understanding of their mating patterns and evolution. Two closely related South American Nothofagus species were compared with regard to the differentiation times and positions of staminate and pistillate flowers along their parent growth units (GUs) by quantitative means.

Methods

Two samples of GUs that had extended in the 2004–2005 growing season were taken in 2005 and 2006 from trees in the Lanín National Park, Patagonia, Argentina. For the first sample, axillary buds of the parent GUs were dissected and the leaf, bud and flower primordia of these buds were identified. The second sample included all branches derived from the parent GUs in the 2005–2006 growing season.

Key Results

Both species developed flowering GUs with staminate and/or pistillate flowers; GUs with both flower types were the most common. The position of staminate flowers along GUs was similar between species and close to the proximal end of the GUs. Pistillate flowers were developed more distally along the GUs in N. alpina than in N. obliqua. In N. alpina, the nodes bearing staminate and pistillate flowers were separated by one to several nodes with axillary buds, something not observed in N. obliqua. Markovian models supported this between-species difference. Flowering GUs, including all of their leaves and flowers were entirely preformed in the winter buds.

Conclusions

Staminate and pistillate flowers of N. alpina and N. obliqua are differentiated at precise locations on GUs in the growing season preceding that of their antheses. The differences between N. alpina and N. obliqua (and other South American Nothofagus species) regarding flower distribution might relate to the time of anthesis of each flower type and, in turn, to the probabilities of self-pollination at the GU level.Key words: Branch, bud, growth unit, Markovian models, Nothofagus alpina, N. obliqua, Patagonian forests, pistillate flower, preformation, staminate flower  相似文献   

16.
A new species ofCroton,C. dissectistipulatus, is described from Amazonian Brazil. This species is superficially similar toC. timandroides from northeastern and southeastern Brazil, but differs in having petiolate leaves with glandular margins, persistent stipules, conspicuous racemose inflorescences, staminate flowers having externally glabrous sepals and 3 stamens, and pedicellate pistillate flowers. The systematic position ofC. dissectistipulatus relative to the sections ofCroton is discussed.  相似文献   

17.
Anadenanthera colubrina (Vell.) Brenan (Leguminosae-Mimosoideae) is a widely-distributed tree in seasonally dry tropical forests of South America that was classified previously as lacking nectaries. However, some studies have stated that its flowers produce nectar, while others analyzed the composition of unifloral honey produced from A. colubrina flowers, raising the question about nectar production in the species. We studied the pollination and reproductive biology of A. colubrina var. cebil (Griseb.) Altschul in a natural population in the Caatinga, northeastern Brazil. Reproductive phenology, sexual system, floral biology, resource, and pollinators were investigated. We analyzed the breeding system through controlled pollinations for addressing its dependence on pollen vectors for reproduction. Anadenanthera colubrina flowered in the dry season, flower heads are heteromorphic, with staminate flowers at the base and perfect flowers at the apex of the inflorescence, characterizing andromonoecy. Anthesis is diurnal. We observed small drops of nectar at the apex of the petals of some flowers per inflorescence. Together with observations on flower visitor behavior and histochemical tests, we propose that A. colubrina produces floral nectar at the apex of the corolla, characterizing a substitutive nectary (sensu Vogel). This is the first record of substitutive nectary in the Mimosoideae and the first record of andromonoecy in the genus. Bees were the main pollinators (higher frequency), although other insects such as wasps, butterflies, and small beetles were also observed collecting nectar and/or pollen. The species is self-incompatible, thus depending on insect pollen vectors, mainly bees, for reproduction.  相似文献   

18.
Flowering and fruiting biology of Magnolia ovata was studied in Atlantic forests in the interior of São Paulo State, Brazil. The large, bisexual flowers are protogynous, nocturnal, thermogenic and emit a strong scent in two consecutive evenings. In the first night of anthesis, the flowers are in the pistillate stage and thermogenesis starts at about sunset and lasts about 3 h. In the second night, the flowers enter the staminate stage and produce heat for 4 h. Heat is generated by the petals, gynoecium and anthers. Temperatures measured inside the petals reach 26.7 °C and 31.9 °C in the pistillate and staminate stages, 6.0 and 10.6 °C above ambient air, respectively. In the pistillate stage, the perianth opens after sunset and closes tightly a few hours later, and remains closed until the next evening. The initial opening and closing, however, is not synchronous for all flowers during the night. In the following evening, flowers in the staminate stage again open and remain so until the petals drop. Scent compounds, analyzed by GC–MS, contain C5-branched chain compounds, aliphatics, benzenoids and monoterpenoids. Emission of the most prominent compound, C5-branched methyl 2-methyl butyrate, commences before flower opening and continues throughout anthesis, but is accentuated in the thermogenic pistillate and staminate stages. Female and male individuals of only one beetle species, the dynastid scarab Cyclocephala literata, are attracted to the scented flowers in both pistillate and staminate stages. Once inside the flowers they feed on the petals and mate. Tests with synthetic methyl 2-methyl butyrate indicate that this compound is a strong attractant for the beetles. Because this scent compound is strongly emitted in both pistillate and staminate stages, the beetles fly indiscriminately between flowers of both stages. This behavior enhances pollen mixing and effective cross-pollination of the self-compatible species. The evolutionary history of Magnolia appears to be influenced by an ancestral condition of dynastid scarab beetle pollination. Large magnolia flowers are best explained as an archaic structure resulting from the initial association of tropical American species of section Talauma with large and voracious dynastid beetles.  相似文献   

19.
Flexible pedicels are characteristic of birdpollinated plants, yet have received little attention in studies of hummingbird-flower interactions. A major implication of flexible pedicels is that flowers may move during pollination. We examined whether such motion affected interactions between ruby-throated hummingbirds (Archilochus colubris) and jewelweed (Impatiens capensis) by increasing pollen deposition and by altering the effectiveness of nectar removal. For I. capensis, flower mobility enhanced pollen deposition: birds had significantly longer contact with anthers and more pollen deposited on their bills and crowns when foraging at mobile flowers than at flowers that had been experimentally immobilized. In contrast, flower mobility imposed a cost on hummingbirds by significantly increasing their handling times and reducing their extraction rates relative to their interactions with immobile flowers. Field observations indicated that the motion observed during hummingbird visits did not occur when bees (Bombus spp., Apis mellifera) visited I. capensis flowers, which suggests that the mobility of I. capensis flowers is an adaptation for hummingbird pollination.  相似文献   

20.
China took great efforts to reforestation, even turned the long-term forest loss into a net gain, but this cannot hide the loss of species diversity due to destruction of primary forests, habitat loss, invasion of alien species, and over exploitation. Here we provide such a case by recording a dying tree species of Lauraceae from the evergreen forests of SE Yunnan of China and adjoining Vietnam. We made field collections and observations for four consecutive years from 2009 to 2012. Phylogenetic analyses were conducted based on a combined dataset from nrITS and plastid trnL-trnF region, rpl16 intron, and psbA-trnH spacer. The results indicate that the Asiatic Beilschmiedia and Syndiclis are reciprocally monophyletic with Endiandra as a sister group, and both morphology and molecular phylogeny clearly suggest that the new species belongs to Beilschmiedia. Thus Beilschmiedia turbinata Bing Liu et Y. Yang is illustrated and described as new to science, color plates, line drawings, distribution map and comparison with related species are provided. This new species is similar to B. yunnanensis in the small and ferruginous-brown tomentose terminal buds, elliptic to oblong-lanceolate and alternate or subopposite leaves bearing the fine veinlet reticulation, but differs from the latter by the smaller flowers, the eglandular stamens of the third whorl, and the large turbinate furfuraceous fruits.  相似文献   

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