Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Flowers

  • female flower
  • individual flower
  • male flower
  • many flower
  • open flower
  • pin flower
  • staminate flower

  • Terms modified by Flowers

  • flower bud
  • flower colour
  • flower density
  • flower development
  • flower extract
  • flower head
  • flower locus c
  • flower morphology
  • flower number
  • flower production
  • flower scent
  • flower species
  • flower structure
  • flower thrips
  • flower visitation
  • flower visitor

  • Selected Abstracts


    First page of article [source]


    EVOLUTION, Issue 1 2009
    Anton Pauw
    The idea of coevolution originated with Darwin's proposal that long-proboscid pollinators and long-tubed flowers might be engaged in reciprocal selection, but this has not been demonstrated. Here we test key aspects of Darwin's hypothesis of reciprocal selection in an experiment with naturally interacting populations of extremely long-proboscid flies (Moegistorhynchus longirostris: Nemestinidae) and long-tubed irises (Lapeirousia anceps: Iridaceae). We show that the benefit derived by both the fly (volume of nectar consumed) and the plant (number pollen grains received) depends on the relative length of their interacting organs. Each trait is shown to act both as agent and target in directional reciprocal selection, potentially leading to a race. This understanding of how fitness in both species varies in relation to the balance of their armament allows us to make tentative predictions about the nature of selection across multiple communities. We find that in each community a core group of long-tubed plant species might together be involved in diffuse coevolution with the fly. In poorly matched populations, the imbalance in armament is too great to allow reciprocal selection to act, and these species might instead experience one-sided selection that leads to convergence with the core species. Reciprocal selection drives the evolution of the community, then, additional species become attached to the network of interacting mutualists by convergence. [source]

    Everlasting Flower: A History of Korea By Keith Pratt

    HISTORY, Issue 307 2007
    No abstract is available for this article. [source]

    Allelopathic Effects of Parthenium hysterophorus Extracts on Seed Germination and Seedling Growth of Eragrostis tef

    T. Tefera
    The present study was conducted to investigate the allelopathic effects of Parthenium hysterophorus weed on seed germination and seedling growth of tef. Flower, stem, root and leaf aqueous extracts of Parthenium at 0, 1, 5, and 10 % concentrations were applied to determine their effect on tef seed germination and seedling growth under laboratory conditions. Increasing concentrations of aqueous extracts of Parthenium from leaf and flower inhibited seed germination and complete failure of seed germination was recorded when the extract concentration from the leaf part was 10 %. In contrast, aqueous extracts from stem and root had no effect on tef seed germination. Roots appeared more sensitive to allelopathic effect than shoots. Extracts from flower, root and stem had a stimulatory effect on shoot length at all concentration levels, as against an inhibitory effect of leaf extracts. Root extracts at low concentration (1 %) greatly promoted root length but aqueous extracts from leaf and flower inhibited root length. [source]


    PALAEONTOLOGY, Issue 3 2007
    Abstract:, Three specimens of the small breviconic ellesmeroceratid Paradakeoceras minor Flower, 1964 from the Tremadocian of the New York area preserve the annular elevation and muscle scars in moulds of the body chamber. The annular elevation is positioned at the base of the body chamber and is wider on the convex side of the shell than on the concave side. Multiple paired muscle scars can be seen within this annular elevation. A well-preserved body chamber of the breviconic ellesmeroceratid Levisoceras cf. edwardsi Ulrich, Foerste and Miller is described. Its body chamber shows a strong anterior,posterior asymmetry, which is common within the Ellesmeroceratida. The shape of the body chamber and of the soft body attachment structures has led to a reconstruction of an ellesmeroceratid soft body that is organized like a primitive conchiferan mollusc. Based on this reconstruction, a tryblidian cephalopod ancestor is supported. An evolutionary scenario is reconstructed from an ancestral nautiloid that is stretched along the anterior,posterior axis, and has serially arranged shell muscles and a small mantle cavity, towards a modern cephalopod with a dorsal,ventral body orientation, reduced number of shell muscles and a large mantle cavity. [source]

    Pattern of Flower and Fruit Production in Stryphnodendron adstringens, an Andromonoecious Legume Tree of Central Brazil

    PLANT BIOLOGY, Issue 6 2003
    P. L. Ortiz
    Abstract: Patterns of flower and fruit production in racemes of Stryphnodendron adstringens, an andromonoecious Brazilian savanna tree species, were studied in two natural areas near Uberlândia-MG. Racemes were divided in three parts: apex, centre, and base. Number of flowers, gender, and nectar and pollen production were analyzed for each section. Frequency of visitors to each part of the inflorescence was also quantified. Hand self- and cross-pollinations were performed in complete racemes and fruit set used to determine breeding system. The racemes produced a mean of 329 flowers, more densely packed in the central portion. Hermaphrodite and male flowers occur along the inflorescence but hermaphrodite flowers are more common in the centre. Fruit set was markedly low but does not seem to be limited by pollination service, since free open-pollinated racemes and hand cross-pollinated ones do not differ in fruit production rates. Fruits resulted mostly from cross-pollinated flowers and fruit production was biased to the central portion of the raceme. Nectar yield was higher in the central portion of the raceme and visitors arrived more commonly on this portion of the inflorescence. However, most flowers did not produce nectar. The pattern of fruit production seems to be a consequence of the hermaphrodite flower distribution in the raceme and it is not constrained by pollen flow or flower opening sequence. [source]

    Morphological, Biochemical and Molecular Characterization of Herpetomonas samuelpessoai camargoi n. subsp., a Trypanosomatid Isolated from the Flower of the Squash Cucurbita moschata

    ABSTRACT. We report the morphological, biochemical and molecular characteristics of a trypanosomatid isolated from the flower of Cucurbita moschata. Although the trypanosomatid was isolated from a plant, the lack of recognition of Phytomonas-spccific molecular markers based on spliced-leader and ribosomal genes as well as by monoclonal antibodies specific for Phytomonas argues against assigning it to this genus. Because the isolate displayed typical opisthomastigote forms in culture, it is assigned to the genus Herpetomonas. Analysis of randomly amplified polymorphic DNA (RAPD) patterns and characterization of ribosomal SSU and ITS markers suggest that it is more closely related to H. samuelpessoai than to any other species. However, the presence of spined flagellates in culture (displaying lateral expansions of the plasma membrane originating near the flagellar pocket) and isolate-specific RAPD fingerprints argue strongly that the trypanosomatid belongs to a new subspecies, for which the name Herpetomonas samuelpessoai camargoi n. subsp. is proposed. [source]

    Analysis of morphological variation of the Acer tschonoskii complex in eastern Asia: implications of inflorescence size and number of flowers within sect.

    Flower and fruit specimens of 184 individuals were sampled to investigate patterns of intraspecific variation and to evaluate recognition of taxa within the Acer tschonoskii complex using morphometric analysis. Previous taxonomic treatments have considered A. tschonoskii var. rubripes (= A. komarovii) and A. tschonoskii var. tschonoskii to be separate species. The morphological discontinuity between these two taxa was evident in peduncle and pedicel length, and in number of flowers. In addition, the delimitations of some species within sect. Macrantha were clarified using these diagnostic characters. In view of the geographical distribution of the A. tschonoskii complex, which includes many taxa of sect. Macrantha from China to Japan through Korea, the long raceme with many flowers (A. sikkimense) and unlobed leaf are considered more primitive than the short raceme with a small number of flowers and five-lobed leaf (A. maximowiczii and A. komarovii). However, many intermediate taxa were present. This study also suggests that several Chinese taxa, such as A. metcalfii, A. taronense, A. hookeri and A. grosseri, may be subject to different taxonomic interpretation and should be reinvestigated morphologically. © 2003 The Linnean Society of London. Botanical Journal of the Linnean Society, 2003, 143, 29,42. [source]

    From the Linden Flower to Linden Honey , Volatile Constituents of Linden Nectar, the Extract of Bee-Stomach and Ripe Honey

    Regula Naef
    Honey is produced by honeybees (Apis mellifera), which collect nectar from flowers, digest it in their bodies, and deposit it in honeycombs, where it develops into ripe honey. We studied the evolution of the volatile constituents from the nectar of linden blossoms (Tilia cordata) to honey via the ,intermediate' honeybee. The sampling of the contents of the honey stomach or honey sack of the bee is unique. Extracts were prepared from nectar, from the liquid of the honey stomach, and from ripe honey. The chemistry is extremely complex, and compounds spanning from monoterpenes (hydrocarbons, ethers, aldehydes, acids, and bifunctional derivatives), isoprenoids, aromatic compounds (phenylpropanoids, phenols), and products degraded from fatty acids to alkaloids, were identified. Some compounds definitely stem from the plants, whereas other interesting constituents can be attributed to animal origin. Two derivatives of decanoic acid, 9-oxodec-2-enoic acid (12) and 9-hydroxydec-2-enoic acid, identified in the honey are known to be constituents of the so-called ,Queen's pheromone'. Two metabolites of these acids were identified in the extract of the honey stomach: 8-oxononanal (10), a new natural product, and 8-oxononanol (11). There structures were confirmed by synthesis. Nectar and honey stomach contain many aldehydes, which, due to the highly oxidative atmosphere in the honeycomb, are found as corresponding acids in the honey. Two acids were newly identified as 4-isopropenylcyclohexa-1,3-diene-1-carboxylic acid (14) and 4-(1-hydroxy-1-methylethyl)-cyclohexa-1,3-diene-1-carboxylic acid (15). [source]

    Protein Fractionation of Cowpea (Vigna unguiculata (L.) Walp) Leaf, Flower and Seed by Capillary Electrophoresis and Its Potential for Variety Identification

    Sirithon Siriamornpun
    Abstract The proteins of different faction of cowpea [Vigna unguiculata (L.) Walp] were fractionated by capillary electrophoresis (CE). The extracting solvent system was one of the most critical factors in the optimization exercise. To improve reproducibility, seed samples needed to be defatted with chloroform/methanol (V:V=2:1) as preferred prior to protein extraction. Proteins were extracted from seeds, leaves and flowers with 50% aqueous 1-propanol and separated on a 50 (m×20 cm fused silica capillary column using a UV detector at 200 nm. Separation was conducted at constant voltage (10 kV, 40°C), using iminodiacetic acid (pH 2.5) containing 0.05% hydroxypropylmethylcellulose (HPMC) and 20% acetonitile. The results showed that proteins extracted from all fraction of cowpea were successfully separated by CE in less than 20 min. Seed extracts provided the greatest number of eluted protein peaks, followed by flower and leaf, respectively. The seed-protein extracts provided unique CE patterns for different varieties; hence the seed was the tissue chosen as being most suitable for variety identification. As a result, an optimized procedure was developed to provide rapid identification of cowpea varieties, based on capillary electrophoregram patterns. [source]

    Flowers of Water: Homegardens and Gender Roles in a Riverine Caboclo Community in the Lower Amazon, Brazil

    Assistant Professor Rui Sérgio Sereni Murrieta
    First page of article [source]

    Wild Flowers at Wakehurst

    Arthur Hoare
    Summary. There are over three hundred species of native or naturalised plants found growing wild in Wakehurst Place. Certain areas away from the formal beds have been left wild, but are managed for the encouragement of wild flowers and a visitor taking a gentle stroll around the gardens will have no difficulty in finding many of them. [source]

    Flower-feeding affects mating performance in male oriental fruit flies Bactrocera dorsalis

    Todd E. Shelly
    Summary 1. Males of the oriental fruit fly Bactrocera dorsalis are attracted to and feed on flowers of the golden shower blossom Cassia fistula. Flowers of this plant contain methyl eugenol, the metabolites of which apparently function in the synthesis of male sex pheromone. 2. The goal of the study reported here was to determine whether feeding on C. fistula flowers enhanced male mating success. Mating frequencies of unfed (control) and fed (treated) males were compared in trials conducted 0 (same day), 2, 7, or 21 days after treated males were exposed to the flowers. Trials were performed using flowers from three trees of C. fistula to investigate whether the effects of floral feeding were similar among different plants. 3. For all three trees, treated males accounted for a disproportionately large number of matings in trials performed 0, 2, and 7 days after floral feeding by the treated males. For two of the trees, treated males also had a mating advantage 21 days after flower-feeding. 4. Additional tests were conducted to compare female attraction to perch sites of control and treated males. When at a lek, males exhibit rigorous wing-fanning behaviour, presumably to increase dispersal of the sex pheromone. Floral feeding had no significant effect on the level of wing-fanning. Significantly more female sightings were recorded for perches of treated than control males, however, suggesting that the treated males produced a pheromone more attractive to females than did control males. [source]

    Houses, Flowers, and Frameworks: Cavell and Mulhall on the Moral of Skepticism

    Edward Witherspoon
    First page of article [source]

    The influence of pollinator abundance on the dynamics and efficiency of pollination in agricultural Brassica napus: implications for landscape-scale gene dispersal

    Summary 1It is important to understand the pollination processes that generate landscape-scale gene dispersal in plants, particularly in crop plants with genetically modified (GM) varieties. In one such crop, Brassica napus, the situation is complicated by uncertainty over the relative importance of two pollen vectors, wind and insects. 2We investigated pollination in two fields of B. napus that bloomed at different times of year (April vs. July) and attracted different abundances of foraging social bees. Rates of pollen transfer were quantified by counting the pollen grains deposited on stigmas and remaining in the anthers at intervals after flower opening. 3Flowers open in April were adequately pollinated only after 5 days and only 10% received even a single bee visit. Flowers open in July received three bee visits per hour and were fully pollinated within 3 h. 4Based on published measurements of airborne pollen dispersal, we estimate that wind-pollination from a hypothetical field 1 km distant could have fertilized up to 0·3% of the field's seed when bees were scarce in April but only up to 0·007% when bees were abundant in July. 5The efficiency of pollination (the proportion of pollen released from anthers that landed on receptive stigmas) was seven times greater in July (1·5%) than in April (0·2%). The relatively high efficiency of insect pollination may help to explain the evolutionary maintenance of entomophily. 6Synthesis and applications. Our results begin to resolve a long-standing inconsistency among previous studies by suggesting that the susceptibility of fields of B. napus to long-distance cross-pollination by wind depends on the level of bee activity. Models for predicting GM gene flow at the landscape-scale in this crop should take this into account. [source]

    Ornithophilous canopy species in the Atlantic rain forest of southeastern Brazil

    Márcia A. Rocca
    ABSTRACT In tropical ecosystems, birds play a relevant role in plant reproduction. Although hummingbirds are regarded as the most important vertebrate pollinators in the Neotropics, the possible role of perching birds as pollinators has been neglected. From 2003 to 2005, we observed 68 species of plants visited by birds in an Atlantic rainforest in southeastern Brazil, including three canopy species: Spirotheca rivieri (Malvaceae, Bombacoidea), Schwartzia brasiliensis (Marcgraviaceae), and Psittacanthus dichrous (Loranthaceae). Flowers of these three species were visited by 15 different species of perching birds and by hummingbirds. The flowers of these three plants are colorful, ranging from deep red or purple to orange. Spirotheca rivieri blooms during the austral winter and Schwartzia brasiliensis during the summer. The flowers of these two species produce copious amounts of dilute nectar in easily accessible structures and both species appear to depend primarily on perching birds as pollinators, with hummingbirds being secondary or minor pollen vectors. The tubular, narrow flowers of P. dichrous are produced during the austral summer and are visited primarily by hummingbirds. Perching birds also visit the flowers, but destroy them. Our results suggest that previous estimates of the number of perching birds that feed on nectar may be too low and that flowers pollinated by perching birds may be more common in the canopy of Neotropical forests than previously thought. SINOPSIS En los ecosistemas tropicales, las aves desempeñan un papel importante en la reproducción de las plantas. Aunque se consideran a los colibríes como el grupo más importante de polinizadores en el neotrópico, este posible rol ha sido relegado en las aves de percha. De 2003,2005, observamos 68 especies de plantas visitadas por aves en el Bosque Pluvial del Atlántico en el sudeste de Brasil. Las flores en el dosel de Spirotheca rivieri (Malvaceae, Bombacoidea), Schwartzia brasiliensis (Marcgraviaceae) y Psittacanthus dichrous (Loranthaceae) fueron visitadas por 15 especies de aves, siendo colibríes y especies de aves de percha. Las flores de estas plantas son de gran colorido, desde rojo subido o púrpura hasta anaranjado. Spirotheca rivieri florece durante el invierno austral y Schwartzia brasiliensis durante el verano. Las flores de estas especies producen grandes cantidades de néctar y tienen estructuras de gran accesibilidad para las aves. Ambas especies parecen depender principalmente de aves de percha como polinizadores, siendo los colibríes polinizadores secundarios o vectores menores de polen. Las flores angostas y tubulares de P. dichrous se producen durante el verano austral y son visitadas, principalmente, por colibríes. Hay aves de perchas que también visitan a estas flores, pero al hacerlo las destruyen. Nuestros resultados sugieren que los estimados previos del número de aves de percha que se alimentan de néctar son muy bajos y que la polinización por aves de percha, parece ser más común en el dosel forestal de los bosques neotropicales que lo previamente pensado. [source]

    Flowers and Leaves of Tropaeolum majus L. as Rich Sources of Lutein

    P.Y. Niizu
    ABSTRACT: As increasing evidence supports the role of lutein and zeaxanthin in reducing the risk of cataract and macular degeneration, food sources of these carotenoids are being sought. In the present study, the lutein content of the edible flowers and leaves of Tropaeolum majus L. was determined by high-performance liquid chromatography-photodiode array detector (HPLC-PDAD), complemented by HPLC-mass spectrometry (MS) for identification. Chemical reactions were also used as identifying parameters. The yellow and brownish orange flowers had 450 ± 60 ,g/g and 350 ± 50 ,g/g lutein, respectively. Violaxanthin, antheraxanthin, zeaxanthin, zeinoxanthin, ,-cryptoxanthin, ,-carotene, and ,-carotene were also detected at very low levels. The leaves had 136 ± 18 ,g/g lutein, 69 ± 7 ,g/g ,-carotene, 74 ± 23 ,g/g violaxanthin, and 48 ± 13 ,g/g neoxanthin. Lutein was partly esterified in the flowers and unesterified in the leaves. The flowers of T. majus are therefore excellent food sources of lutein and the leaves good sources of both lutein and the provitamin A ,-carotene. [source]

    Walnut Staminate Flowers Can Be Explored as a Supplementary Plant Oil Source

    Husen Jia
    Abstract Fossil fuel is currently the major energy source driving global socio-economy, but its stock is being heavily depleted due to increasing anthropogenic activities worldwide. There are also concerns regarding the burning of fossil fuels, which contributes to global climate warming and air pollution. As such, the development of biodiesel as a non-toxic, biodegradable, and renewable alternative energy source using oil crops such as soybean and rapeseed has quickly emerged in the West countries. However, the production of oil crops in China is far from sufficient to meet the demands of the country's population of 1.3 billion, and increasing oil crop production is inhibited by a severe shortage of agricultural land, which currently averages 0.2 acre per person and, as such, is less than half the world average. The current national policy in China regarding land use is more towards revering cultivated lands in ravins and hills to forestry, which presents an ideal opportunity to further develop plantations of walnut (Juglans regia L.) trees, a plant that is tolerant to drought and infertile soils and has a high oil content. Study in this paper shows that one ament of walnut staminate flowers produces about 0.168 g dry pollen, and the dry pollen contained 49.67% oil. Based on this discovery, oil yield obtained from staminate flowers is estimated to reach 6.95% of that from walnut nuts. Thus walnut staminate flower is suggested to explore as supplementary plant oil source, and has a great opportunity to utilize as a biodiesel feedstock. (Managing editor: Wei Wang) [source]

    Intrafloral differentiation of stamens in heterantherous flowers

    Zhong-Lai LUO
    Abstract Flowers that have heteromorphic stamens (heterantherous flowers) have intrigued many researchers ever since the phenomenon was discovered in the 19th century. The morphological differentiation in androecia has been suggested as a reflection of "labor division" in pollination in which one type of stamens attracts pollinators and satisfies their demand for pollen as food and the other satisfies the plant's need for safe gamete dispersal. The extent and patterns of stamen differentiation differ notably among taxa with heterantherous flowers. Seven species with heteromorphic stamens in three genera were sampled from Leguminosae and Melastomataceae, and the morphological difference of androecia, pollen content, pollen histochemistry and viability, pollen micro-morphology, as well as the main pollinators were examined and compared. Pollen number differs significantly between stamen sets of the same flower in most species investigated, and a correlation of pollen number and anther size was substantiated. Higher pollen viabilities were found in the long (pollinating) stamens of Senna alata (L.) Roxb. and S. bicapsularis (L.) Roxb. Dimorphic pollen exine ornamentation is reported here for the first time in Fordiophyton faberi Stapf. The height of stigma and anther tips of the long stamens in natural conditions was proved to be highly correlated, supporting the hypothesis that they contact similar areas of the pollinator's body. [source]

    Pollination ecology of Isoglossa woodii, a long-lived, synchronously monocarpic herb from coastal forests in South Africa

    PLANT BIOLOGY, Issue 3 2010
    M. E. Griffiths
    Abstract Synchronous monocarpy in long-lived plants is often associated with pollination by wind, in part because infrequent mass flowering may satiate pollinators. Selfing in synchronous monocarps may provide reproductive assurance but conflict with the benefits of outcrossing, a key evolutionary driver of synchrony. We predicted that animal-pollinated species with synchronous flowering would have unspecialised flowers and attract abundant generalised pollinators, but predictions for selfing and outcrossing frequencies were not obvious. We examined the pollination biology of Isoglossa woodii (Acanthaceae), an insect-pollinated, monocarpic herb that flowers synchronously at 4,7-year intervals. The most frequent visitor to I. woodii flowers was the African honeybee, Apis mellifera adansonii. Hand-pollination failed to enhance seed production, indicating that the pollinators were not saturated. No seed was set in the absence of pollinators. Seed set was similar among selfed and outcrossed flowers, demonstrating a geitonogamous mixed-mating strategy with no direct evidence of preferential outcrossing. Flowers contained four ovules, but most fruits only developed one seed, raising the possibility that preferential outcrossing occurs by post-pollination processes. We argue that a number of the theoretical concerns about geitonogamous selfing as a form of reproductive assurance do not apply to a long-lived synchronous monocarp such as I. woodii. [source]

    Development of Distylous Flowers and Investment of Biomass in Male and Female Function in Palicourea padifolia (Rubiaceae)

    PLANT BIOLOGY, Issue 6 2007
    A. Hernández
    Abstract: Knowledge of developmental pathways for achieving differences in style and anther heights, in concert with those of ancillary features accompanied with data in regard to biomass investment to male and female function, provide an excellent opportunity for examining the developmental correlations between primary and ancillary floral traits so as to understand the evolution of heterostyly. The ontogenetic relationships between bud length and anther height and between bud length and style height, and between bud length versus bud width, anther length, and number of pollen grains per anther for long-styled (LS) and short-styled (SS) morphs of P. padifolia are described. We also described the ontogenetic biomass allocation to male and female function and to corolla with elongation of buds harvested at regular intervals. We observed an early termination of stylar growth in SS buds, whereas LS styles steadily increased in size. Morph differences for relative growth rates were significant for anther height, anther length, and pollen number but not for bud width. Bud width and anther length had a negative allometric relationship with bud elongation. The relationship between bud length and number of pollen grains per anther was positive and morph differences in pollen number were detected at later stages of development. An increase in corolla mass involved a disproportionate allocation to the female function in SS flowers and male allocation was similar for the two morphs over the course of development. Our results are consistent with theoretical and empirical data for distylous species with an approach herkogamous ancestor, and with the more general hypothesis of ontogenetic lability of heterostyly, in which morph differences in style and anther heights are achieved in various ways. Variations observed in sexual investment between floral morphs suggest differences in sex expression during flower development. [source]

    Immunolocalization of the PmSUC1 Sucrose Transporter in Plantago major Flowers and Reporter-Gene Analyses of the PmSUC1 Promoter Suggest a Role in Sucrose Release from the Inner Integument

    PLANT BIOLOGY, Issue 3 2007
    C. Lauterbach
    Abstract: This paper presents a detailed analysis of the PmSUC1 gene from Plantago major, of its promoter activity in Arabidopsis, and of the tissue specific localization of the encoded protein in Plantago. PmSUC1 promoter activity was detected in the innermost layer of the inner integument (the endothel) of Arabidopsis plants expressing the gene of the green fluorescent protein (GFP) under the control of the PmSUC1 promoter. This promoter activity was confirmed with a PmSUC1-specific antiserum that identified the PmSUC1 protein in the endothel of Plantago and of Arabidopsis plants expressing the PmSUC1 gene under the control of its own promoter. PmSUC1 promoter activity and PmSUC1 protein were also detected in pollen grains during maturation inside the anthers and in pollen tubes during and after germination. These results demonstrate that PmSUC1 is involved in sucrose partitioning to the young embryo and to the developing pollen and growing pollen tube. In the innermost cell layer of the inner integument, a tissue that delivers nutrients to the endosperm and the embryo, PmSUC1 may catalyze the release of sucrose into the apoplast. [source]

    Evolution of Funnel-Revolver Flowers and Ornithophily in Nasa (Loasaceae)

    PLANT BIOLOGY, Issue 1 2006
    M. Weigend
    Abstract: Floral morphology, distribution, and flower visitors for 60 taxa of Nasa are investigated and compared to molecular trees inferred both from a combined marker analysis (ITS1 and trnLUAA) and from a single marker (ITS1). Flowers conform to two different floral types: Firstly, "tilt-revolver flowers", with spreading to reflexed, white to yellow petals and small, brightly coloured floral scales contrasting with the petals and firmly enclosing the nectar (Saccatae and Carunculatae); secondly, "funnel-revolver flowers", with half-erect to erect, orange to red petals and floral scales not contrasting with the petals, or enclosed in the corolla, and nectar freely accessible by funnel-shaped floral scales (Alatae, Grandiflorae, and N. venezuelensis species group). Phylogenetic analysis shows that "tilt-revolver flowers" represent the plesiomorphic condition by outgroup comparison. The two groups with tilt-revolver flowers in Nasa are not monophyletic (Saccatae are paraphyletic, Carunculatae are polyphyletic). Most Saccatae fall into two monophyletic assemblages, the N. poissoniana species group and the N. triphylla species group. The remainder of Saccatae group either with Grandiflorae (N. insignis species group) or with Alatae (N. laxa species group). The clades retrieved in the molecular analysis contradict the traditional classification, but are congruent with vegetative morphology, details of the flower morphology, and biogeography. "Funnel-revolver flowers" represent the derived condition, but molecular data suggest a convergent development (at least twice independently), since the corresponding species do not constitute a monophyletic group. "Tilt-revolver flowers" are visited and pollinated by bees (especially Colletidae), whereas "funnel-revolver flowers" are mostly visited by hummingbirds. The transition from melittophily to ornithophily may have been the license for the colonization of, and the diversification in, both cloud forest and high Andean habitats. [source]

    Pattern of geographical variation in petal shape in wild populations of Primula sieboldii E. Morren

    Abstract The petal shape of Primula sieboldii E. Morren (Primulaceae) is diverse in wild populations. In this study, we investigated population differentiation in the petal shape of P. sieboldii using image analysis. Flowers were sampled from 160 genets from eight wild populations in the western to north-eastern parts of the Japanese archipelago. Principal component (PC) analysis of 40 coefficients of elliptic Fourier descriptors (EFDs) detected three major characteristics of petal shape variation: the ratio of length to width (PC1), the depth of the head notch (PC2) and the position of the center of gravity (PC3). To test the association between divergence in petal shape and geographical and genetic distances, we calculated two types of pairwise population distances for petal shape: Mahalanobis distances for the 40 EFD coefficients and for the first three PCs. The existence of an association between neutral genetic markers and petal shape was revealed by the Mahalanobis distances based on the 40 EFD coefficients, suggesting that evolutionary forces, such as founder effect and isolation by distance effect, are probably the main causes of differentiation in petal shape. In contrast, we found no association between Mahalanobis distances for the first three PCs and geographical and genetic distances. The discrepancy between the two petal shape distances indicated that the population differentiation promoted by the founder effects and isolation by distance effect appears mainly as subtle changes in petal shape rather than in major characteristics of petal shape variation. [source]

    Reproductive biology of two Cattleya (Orchidaceae) species endemic to north-eastern Brazil

    Abstract The reproductive biology of the endemic Cattleya elongata and the endemic and critically endangered Cattleya tenuis (Orchidaceae) was studied in areas of ,campo rupestre' and ,caatinga' vegetation, respectively, in the Chapada Diamantina, north-eastern Brazil. Floral visitors and their behavior were recorded, and experimental pollinations were carried out to determine the breeding systems of these species. The species have similar flower morphology, flower in synchrony and both are pollinated by queens of Bombus (Fervidobombus) brevivillus (Apidae, Bombina). Flowers of both species do not present nectar despite the presence of a nectary-like cuniculus. Cattleya tenuis presented low natural fruit set (10%), while C. elongata presented a higher fruit set (25%). Both species are self-compatible, and only C. tenuis presented inbreeding depression, expressed as reduced seed viability in self-pollinations compared with cross-pollinations. The species have a parapatric distribution and differences in their habitats probably act as the principal barriers to the formation of natural hybrids. [source]

    Flowers Are an important food for small apes in southern Sumatra

    Susan Lappan
    Abstract Flowers are included in the diets of many primates, but are not generally regarded as making an important contribution to primate energy budgets. However, observations of a number of lemur, platyrrhine, and cercopithecine populations suggest that some flower species may function as key primate fallback foods in periods of low abundance of preferred foods (generally ripe fruits), and that flowers may be preferred foods in some cases. I report heavy reliance on flowers during some study months for a siamang (Symphalangus syndactylus) population in southern Sumatra. Siamangs at Way Canguk spent 12% of feeding time eating flowers from October 2000 to August 2002, and in 1 month flower-feeding time exceeded 40% of total feeding time. The overall availabilities of fig and nonfig fruits, flowers, and new leaves in the study area were not significant predictors of the proportion of time that siamangs spent consuming any plant part. However, flower-feeding time was highest in months when nonfig fruit-feeding time was lowest, and a switch from heavy reliance on fruit to substantial flower consumption was associated with a shift in activity patterns toward reduced energy expenditure, which is consistent with the interpretation that flowers may function as a fallback food for Way Canguk siamangs. Hydnocarpus gracilis, a plant from which siamangs only consume flowers, was the third-most-commonly consumed plant at Way Canguk (after Ficus spp. and Dracontomelon dao), and flowers from this plant were available in most months. It is possible that relatively high local availability of these important siamang plant foods is one factor promoting high siamang density in the study area. Am. J. Primatol. 71:624,635, 2009. © 2009 Wiley-Liss, Inc. [source]

    Favored Flowers: Culture and Economy in a Global System by Catherine Ziegler

    Yves Laberge
    No abstract is available for this article. [source]

    What's Wrong with This Approach, Comrades?

    Bee Flowers
    Though strenuously avoiding the ,Modernist' and ,International Style' labels, postwar USSR, along with its Western counterparts, plunged headlong into a system-building programme. Today, Russians know of virtually no other form of housing and, as photographer Bee Flowers observes, the construction sector continues to produce ever larger buildings, for no apparent reason other than habit. [source]

    Rodent pollination in the Cape legume Liparia parva

    AUSTRAL ECOLOGY, Issue 2 2009
    Abstract Flowers of Liparia parva from which rodents were excluded had lower seed-set than open flowers. The rodent Acomys subspinosus was captured in the vicinity of this plant species and captures had substantial numbers of L. parva pollen in their scats. Captured individuals of A. subspinosus visited L. parva flowers in tanks and removed standard petals to obtain the nectar. Typical of rodent-pollinated species, L. parva, flowered in winter and flowers mostly opened in the evenings and the stigma-nectar distance was about 10 mm. This is the first evidence for rodent pollination in the large cosmopolitan family, the Fabaceae. [source]

    Bird Pollination of Explosive Flowers While Foraging for Nectar and Caterpillars,

    BIOTROPICA, Issue 5 2006
    Kayna Agostini
    ABSTRACT Mucuna (Fabaceae) has explosive flowers that open only if a pressure is applied on their wings and keel. The cacique Cacicus haemorrhous inserts its bill into a flower and spreading its mandibles apart it opens the flower to take nectar. This icterine bird also preys upon caterpillars of the butterfly Astraptes talus that pupates within the flowers. Foraging with use of bill movements to take nectar or insects within a flower is an adequate mechanism to open and pollinate explosive flowers. We suggest that a plausible behavioral scenario for the pollination relationship between icterines and Mucuna -like flowers might start with the birds' searching for insects within flowers. RESUMEN El género Mucuna (Fabaceae) tiene flores explosivas que abren cuando se aplica una presión sobre sus alas o quillas. El boyero cacique, Cacicus haemorrhous, introduce su pico dentro de la flor y expande sus mandibulas abriendo la flor para beber el néctar. Esta ave Icterinae también depreda larvas de la mariposa Astraptes talus, la cual empupa dentro de las flores. El forrajeo con uso de movimientos del pico, para consumir el néctar o de insectos dentro de una flor, es un mecanismo adecuado para abrir y polinizar las flores explosivas. Sugerimos que este es un escenario comportamental razonable para la relación de la polinización entre especies de Icterinae y flores del tipo Mucuna, que podría iniciar con la búsqueda de las aves por insectos dentro de las flores. [source]