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The genus Dyckia (Bromeliaceae) is endemic to South America, and its species show important ecological roles in xeric environments. The flowering phenology as well as floral and reproductive biology were monitored monthly in Dyckia dissitiflora at two sites (Bela Vista: 11°42′03.4″ S 39°05′21.7″ W and Barra do Vento: 11°37′58.1″ S 39°03′33.7″ W) in the municipality of Serrinha, Bahia, Brazil. Flowering occurs in the early austral summer with a peculiar time of beginning of anthesis (10:00–11:00), offering resources 18 h after the first petal movements. Pollen viability was 98%, with a high production of pollen grains. Stigma receptivity is continuous from flower opening to senescence, and nectar production initiates at 04:00 and extends until 18:00. The species is self‐compatible and autogamous, but not agamospermic. Pollen tubes developed and reached the micropyle within 24 h in all of the reproductive tests. The hummingbird Chlorostilbon lucidus was the only floral visitor and pollinator (frequency = 0.82 ± 0.02). Fruiting occurs 3 days after anthesis, and the seeds are wind‐dispersed. Self‐compatibility and autogamy are essential strategies for the reproductive success of D. dissitiflora in light of the low number and visit frequency of its pollinators, and it is favored by slow floral movements and the position of the stigmas in relation to stamens. [ABSTRACT FROM AUTHOR]

Reproductive systems and pollination modes (pollination by animals vs. wind) can switch within clades, and many species with an intermediate pollination mode (ambophily, pollination by animals and wind) exist. Here, we investigate the reproductive systems and pollination modes of two common Eurasian species from the Agrimonieae (Rosaceae) that occur in open habitats, Sanguisorba minor and Sanguisorba officinalis. Based on observations from literature, the flowers of both species are visited by insects, but due to flower morphology S. minor is commonly regarded as wind pollinated, while S. officinalis is classified as insect pollinated. By measuring floral traits, such as pollen grain and ovule number per flower, observing flower visitors in natural habitats as well as in the botanical gardens and conducting pollination experiments we found that the reproductive systems and pollination modes of the two species differ: Sanguisorba minor is commonly but infrequently visited by short‐tongued insects but is nevertheless exclusively wind pollinated. However, in contrast to most other wind‐pollinated species, S. minor is highly self‐compatible and even able to set seeds by autogamous selfing. Sanguisorba officinalis, on the other hand, is largely insect pollinated, but wind also contributes to seed set (⁓17% after insect exclusion). This species is able to set seeds by geitonogmous selfing but seed set is higher by outcrossing than by selfing. Thus, our study demonstrates another example of a plant species with small, open flowers arranged in large inflorescences that can be shown to be ambophilous. Further, the study will help to reconstruct the complex evolution of pollination modes in Agrimonieae (Rosaceae). [ABSTRACT FROM AUTHOR]

Impact of pollinator shift on differentiation of floral morphology has attracted the interest of naturalists for many years. A comparative investigation was conducted for determining the pollination characteristics, including pollinator assemblage, floral morphology, flowering phenology, and self-compatibility, of two closely related Clerodendrum species-insular C. izuinsulare and widespread C. trichotomum. Japanese black swallowtail butterflies were the predominant flower visitors in mainland Japan, whereas diurnal hawk moths were predominantly found on the Izu Islands, a chain of oceanic islands located off the southeastern coast of the main Japanese island of Honshu in the west Pacific Ocean. The corolla tube of C. izuinsulare was longer than that of C. trichotomum, whereas the filaments and petals of C. izuinsulare were shorter than those of C. trichotomum. The flowering season of C. izuinsulare was later than that of C. trichotomum. The self-compatibility of C. izuinsulare was higher than that of C. trichotomum. These differences might be associated with the low density of Japanese black swallowtail butterflies and dominance of diurnal hawk moths on the Izu Islands. [ABSTRACT FROM AUTHOR]

Pollination systems may vary in their degree of specialization from generalist to specialist and this is associated with the frequency and efficiency of pollinators. Self-compatibility and a generalist pollination system appear to be adaptations that enhance the ability for colonizing new areas, which is typical of mangrove species. Avicennia schaueriana is a western mangrove species included in Acanthaceae, Lamiales, an order known to have specialized pollination. We aimed to describe the floral morphology and analyze the pollination and reproductive systems of A. schaueriana in a mangrove area on the northern coast of the state of Pernambuco, Brazil, to analyze the possible adaptations of this species to the environment. Avicennia schaueriana is self-compatible; however, pollination activity is essential because there is no spontaneous formation of fruit. Reproductive efficacy was high, indicating pollinator efficiency. Some floral attributes of A. schaueriana suggest specialization; however, the broad spectrum of pollinators observed suggests that it has a generalist pollination system. The way in which pollinators interact with flowers and the environmental conditions may have exerted a selective force on the floral attributes of A. schaueriana, characterizing an adaptive generalized pollination system, which is somewhat specialized. [ABSTRACT FROM AUTHOR]

Ocotea porosa has been extensively exploited over the past few decades because of the quality of its wood. Today, populations are reduced and the species is now included in the Red List of threatened species by the International Union for Nature Conservation. For conservation and management purposes, it is extremely important that we understand its reproductive ecology. Floral morphology was described based on field and scanning electron microscopic examination. The reproductive system was determined through experimentally controlled pollination along with observations of pollen tube growth. Pollinators were identified through field observations. Flowers of O. porosa are small, shallow, inconspicuous, asynchronous and grouped in inflorescences. This species presented self-compatibility, but did not reproduce through apomixy and spontaneous self-pollination was very rare (5%). Despite being monoclinal, flowers were protogynic, and the gynoecium was receptive after the first day of anthesis when the anthers were closed. Spontaneous self-pollination was avoided by the extrorse position of the anthers of the internal stamens. Frankliniella gardeniae (Thysanoptera) was the only pollinating species observed and, after visiting several asynchronous flowers in the same inflorescence, favors geitonogamy. Together the small distance supposedly achieved by thrips in flight and the small population density of O. porosa can reduce the chances of cross-pollination in this species. If so, conservation measures must include preservation of the current population and possibly planting to increase population density. This would reduce the distance between individuals and increase genetic variability. Thrips as pollinators must be included in conservation planning for O. porosa. [ABSTRACT FROM AUTHOR]

Pollen germination and pollen-tube growth under natural conditions were observed in a population of a distylous species, Primula sieboldii, in which partial self-compatibility has been demonstrated in some long-styled genets. We observed post-pollination processes microscopically in styles collected after self-morph and inter-morph hand pollination (with standardized pollen load on the stigmas) in four genets each from the following three 'genet types': self-incompatible long-styled (SI), partially self-compatible long-styled (SC) and self-incompatible short-styled morph genets. Irrespective of the genet type, pollen germination began within 24 h after pollination and tubes of pollen reached to the style base with 48-96 h after inter-morph pollination. Although pollen tubes germinated after self-pollination in the SC genets, the number of germinated pollen tubes was significantly lower than in the case of inter-morph pollination. Few pollen tubes germinated after self-pollination of the SI or short-styled genets. In SC genets, the rate of pollen-tube growth did not differ between self-morph and inter-morph pollination (∼1.9 mm/day). Therefore, differences in self-compatibility between SC and SI genets in P. sieboldii are likely to be attributable to differential pollen germination rates rather than to differential pollen-tube growth rates. [ABSTRACT FROM AUTHOR]

The sex type of Trillium camschatcense has been considered to be strictly monomorphic, composed of only hermaphroditic individuals. However, field observations have detected anther-degenerated (AD) plants coexisting with hermaphrodites. The present study aimed to elucidate whether AD plants could be regarded as females and, if so, how their loss of male function is compensated. Because T. camschatcense retains both self-compatible (SC) and self-incompatible (SI) populations, the frequencies of AD plants in multiple populations (22 SC and eight SI) were examined to predict the fate of these individuals under contrasting breeding systems. Morphological and genetic analyses in a SC population demonstrated that AD plants were completely male sterile, but female fertile. Although the quantity of seed produced was similar, hermaphrodites produced seeds predominantly via selfing, whereas seeds of AD plants were entirely outcrossed. Because inbreeding depression was severe, AD plants achieved a fitness advantage through inbreeding avoidance. However, the frequency of AD plants varied among SC populations (0–42%), suggesting that environmental variance can modify the relative fitness. Conversely, the frequency was suppressed among SI populations (0–2%). Because SI hermaphrodites are free from inbreeding, AD plants would not benefit from inbreeding avoidance and would find it difficult to invade a SI population. [ABSTRACT FROM AUTHOR]

The summer-blooming annual forbs Cleome lutea and Cleome serrulata (Cleomaceae) are native across the US Intermountain West and Rocky Mountains, respectively. Their farmed seed is sought to help rehabilitate western rangelands in those regions. This study of the reproductive biologies and pollinator faunas of C. lutea and C. serrulata is the first for this cosmopolitan family, the sister family to the Brassicaceae. Unlike the S-allele self-incompatibility systems of some Brassicaceae, both species of Cleome were found to be self-fertile and capable of some autogamy. Compared with selfing, outcrossing did not enhance seed set, seed viability or seedling vigor for either species (in fact, selfed progeny were more robust). Large, openly visited plants yielded >20 000 seeds each. Like several species of the sister family Capparaceae, flowers of both species first shed their pollen, secreted nectar and became receptive nocturnally. Although no nocturnal visitors were found, both Cleome species attracted a diverse array of diurnal native bees, wasps and butterflies. Among the many floral generalist bees that work Cleome flowers for pollen and nectar are two managed agricultural pollinators, Apis mellifera and Megachile rotundata. These observations bode well for pollinating C. lutea and C. serrulata in small commercial seed fields. It appears that diverse wild bees would benefit from the addition of native Cleome to restoration seed mixes, with the objective of sustaining native pollinator faunas during the first few years of postfire plant community rehabilitation. [ABSTRACT FROM AUTHOR]

The effects of pollination competition between related species on pollen limitation, selfing ability and heterospecific incompatibility were studied in the alpine snowbed shrubs, Phyllodoce caerulea and Phyllodoce aleutica (Ericaceae) along local snowmelt gradients. The flowering season of these species highly overlapped and they shared the same method of pollination (via bumblebees). The floral density and nectar production were higher in P. caerulea in the early snowmelt habitat, but they were higher in P. aleutica in the late snowmelt habitat, reflecting the species-specific sensitivity to a short growing season. Bumblebee preference shifted from P. caerulea to P. aleutica along the snowmelt gradient, reflecting the changes in the relative reward level between the species. The extent of pollen limitation of P. caerulea was severe in the late snowmelt habitat, whereas that of P. aleutica was obvious in the early snowmelt habitat. A pollination experiment revealed that P. caerulea showed a consistently low selfing ability, whereas P. aleutica showed a high selfing ability in the early snowmelt habitat and shifted to an obligate outcrosser in the late snowmelt habitat. The frequency of interspecific bumblebee movement for P. caerulea from P. aleutica increased in the late snowmelt habitat. To the contrary, the frequency of interspecific movement for P. aleutica from P. caerulea decreased along the snowmelt gradient. P. caerulea did not indicate heterospecific incompatibility to P. aleutica pollen. In contrast, P. aleutica indicated heterospecific incompatibility to P. caerulea pollen, reflecting the high risk of receiving heterospecific pollen as a result of interspecific bumblebee movement. However, heterospecific compatibility of P. aleutica disappeared in the late snowmelt habitat, where the risk of heterospecific pollen receipt was low. Therefore, changes in interspecific bumblebee movement might have been responsible for the variation in heterospecific incompatibility among P. aleutica populations. The local snowmelt gradient creates diverse biological interactions and mating system evolution in the alpine ecosystem. [ABSTRACT FROM AUTHOR]

Abstract Mating systems of sympatric related alpine shrubs, Phyllodoce caerulea and P. aleutica , were compared along snowmelt gradients at three snowbed sites in the Taisetsu Mountains, northern Japan. Seed-set success under natural pollination tended to decrease at late snowmelt places in both species, but the difference between the species was not clear. A pollination experiment revealed that selfing ability differed between the species along the snowmelt gradients. Phyllodoce caerulea showed consistently low selfing ability throughout the gradients even when artificial selfing treatment was performed. Phyllodoce aleutica , whereas, showed high selfing ability at the early and middle snowmelt plots but this abruptly decreased at the late snowmelt plots at every site. These results indicate that P. aleutica is predominantly a selfer at early and middle snowmelt places and shifts to an obligate outcrosser at late snowmelt places. Therefore, variations in the mating system actually occur among neighboring populations along snowmelt gradients probably because of directional selective forces such as interspecific competition for pollinators. [ABSTRACT FROM AUTHOR]

Abstract Deceptive orchid species that offer no floral rewards to pollinators often experience pollinator limitation because they. The breeding system and fruit set were investigated in order to examine pollinator limitation for a population of a deceptive orchid, Pogonia japonica , on a floating peat mat in Mizorogaike Pond, western Japan. Fruit sets for outcross-pollinated, self-pollinated and pollinator-excluded flowers were 75%, 80%, and 0%, respectively. Thus, this species was self-compatible but neither autogamous nor apogamous. The fruit set for open-pollinated flowers was 22.9% and 17.4% in 1994 and 1995, suggesting that pollinator limitation did occur in the field. Larger flowers were more likely to develop into fruit than smaller ones in open pollination (36%vs 8%). Thus, flower size seems to affect fruiting of this species. No effective visits by major pollinators such as bees, which could carry pollinia, were observed during 16.5 h of observation during daytime. Instead, thrips were often found moving on gynostemium or pollinia and circumstantial evidence that suggests thrips may partly transfer pollen in pieces out of a granular pollinium of P. japonica was obtained. Pogonia japonica should come to use thrips as a pollinator to supplement low fruit set under limited flower visitation by major pollinators. [ABSTRACT FROM AUTHOR]

The pollination biology of Heloniopsis orientalis was investigated in the lowlands of south central Japan. The receptive stigma emerges from the perianth before the opening of the perianth, and anther dehiscence is late about two days for perianth opening. The flower therefore is protogynous even though no insects visit the unopen flowers, Receptivity of the stigma is maintained for about 8 days, and even the 10 day-old flower can produce seeds. Self-pollination may be rather common in H. orientalis, which is self-compatible, in particular in the flowers which open on days unfavorable for insect activity. Many species of Diptera and Hymenoptera forage on the flowers, and almost any insect can be their pollinator. Long life, self-compatibility of the flowers, and many kinds of pollinators seem to be factors favoring H. orientalis, which blooms in very early spring when the pollinator supply is unstable but which nevertheless bears many seeds. [ABSTRACT FROM AUTHOR]