Dimorphandra wilsonii Rizzini is a rare species. Although cited as endemic to the Brazilian state of Minas Gerais, it has been recorded only for the municipalities of Paraopeba and Caetanópolis and therefore has not been extensively studied. This long-term, intensive survey, conducted from 2004 to 2012 in the central region of the state, was aimed at assessing its distribution, describing its habitat, and verifying its endemism, as well as assessing threats and determining its conservation status. Given the considerable size of the area to be studied and the difficulty of locating individuals of the species, we adopted popular participation as a complementary tool and we employed spatial distribution modeling. Communities were mobilized through the dissemination of print materials, and interviews were conducted. We visited 74 municipalities and addressed 900 people in search of this species. We found that D. wilsonii is endemic to the cerrado (savanna) and Atlantic Forest in the central region of Minas Gerais, occurring in 16 municipalities. Is not present in any fully protected conservation area, and its population (fewer than 250 individuals) is declining due to habitat destruction, caused mainly by agricultural/livestock and urban expansion, and its conservation status is "critically endangered". (Rizzini & Mattos Filho 1986). Although it has been considered rare and endangered since 1986, it was not until 1997 that it was added to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, where it was listed in the "endangered" category (Walter & Gillett 1998); it was later withdrawn because of the lack of information about the species. In 2000, it was added to the Red List of Endangered Species in the Flora of Minas Gerais, although it was listed there as "vulnerable" rather than "endangered" (Mendonça & Lins 2000). In 2003, we made an expedition to the reported sites of occurrence. We found only 13 adults, all of them in pastures of Urochloa spp. on three farms within the municipalities cited, a situation similar to that reported by Rizzini & Mattos Filho (1986). At that time, we conducted a review of the literature and found only the records of occurrence mentioned above (for Paraopeba and Caetanópolis). Therefore, later that year, the Botanical Garden of the Belo Horizonte Zoological and Botanical Foundation (hereafter referred only as the Botanical Garden), in cooperation with other institutions, initiated a survey of the remaining population (Fernandes et al. 2007), in order to define the distribution of D. wilsonii, characterize its environment, verify its endemism, identify threats to the species, and determine its conservation status. Material and methods Study areaThis study was conducted from January 2004 to October 2012. The study area comprises the central region of the state of Minas Gerais (Fig. 1). According to the Köppen-Geiger climate classification, the climate of the region is type Cwa (mesothermal), with dry winters and an average temperature in t...

Illegitimate flower visitors may reduce the reproductive success of their host plants. Eriocnema fulva , a threatened Melastomataceae of the Atlantic Forest, Brazil, has pollen flowers with poricidal anthers that show frequent damage of floral parts. We identified the flower-damaging bees and determined their impact on fruit set. Bees of seven species visited their flowers, but only three species collected pollen by vibration. With only one visit to a flower patch per 12 h, the frequency of effective buzz pollinating bees was negligible, while flower-damaging workers of the stingless bee Trigona fulviventris (Apidae) accounted for 70% of the visits. During their lengthy visits, they cut anthers to access pollen, and often styles as well. We conclude that the direct negative consequence of flower damage by Trigona bees, as well as their indirect impact by making the flowers unattractive for effective pollinators is a major reason for the low fruit set (6.9%) of E. fulva. Considering the rareness of the plant species, these negative effects put the survival of E. fulva at risk.

RESUMO(Biologia reprodutiva de uma espécie altamente endêmica: Cipocereus lanifl orus Taylor & Zappi (Cactaceae)). Cipocereus lanifl orus N.P. Taylor & Zappi é uma espécie endêmica da Serra do Caraça, Minas Gerais, Brasil. A fi m de se propor estratégias de conservação para esta espécie, estudos sobre sua biologia reprodutiva foram realizados, incluindo fenologia reprodutiva, biologia fl oral, visitantes fl orais e o sistema reprodutivo. O período de fl oração e frutifi cação ocorre de maio a outubro. Poucas fl ores abrem-se por planta a cada noite, podendo produzir até 0.4 ml de néctar, poré 30% destas não apresentam néctar. Cipocereus lanifl orus provavelmente oferece também pólen como recurso. A efi ciência de frutifi cação sob condições naturais de polinização (47%) foi semelhante às encontras para outras espécies de Cactaceae. Pólen de C. lanifl orus foi detectado nos morcegos Anoura geoff roy, Glossophaga soricina e Pygoderma bilabiatum. Entre os caracteres relacionados à quiropterofi lia encontrados em C. lanifl orus, destacamos a coloração creme da parte interna da fl or, os estames numerosos e a antese noturna de curta duração. As fl ores de C. lanifl orus também podem ser visitadas por besouros Nitidulidae, abelhas Trigona fulviventris e beija-fl ores. No entanto, os morcegos são os principais polinizadores desta espécie. Finalmente, por ser uma espécie auto-estéril, C. lanifl orus precisa de um polinizador e está mais suscetível ao risco de extinção se qualquer distúrbio afetar de forma negativa o seu sistema de polinização. In order to propose conservation strategies for this species, its reproductive strategies were investigated, including reproductive phenology, fl oral biology, fl oral visitors and breeding system. Th e fl owering and fruiting period extends from May to October. Few fl owers per plant open each night, producing up to 0.4 ml nectar, but 30% of them are nectarless. Probably pollen is also off ered as a resource. Fruiting effi ciency of C. lanifl orus (47%) is close to that found in other Cactaceae species. Pollen of this species was detected in Anoura geoff roy, Soricina glossophaga and Pygoderma bilabiatum bats. Amongst the characteristics related to bat-pollination syndrome found in C. lanifl orus, the cream-white colouring of the internal part of the fl ower, the numerous stamens and the nocturnal anthesis of short duration can be highlighted. Flowers of C. lanifl orus are also visited by Nitidulidae beetles, Trigona fulviventris bees and hummingbirds, however bats are the main pollinators of this species. Finally, as a self-sterile species, C. lanifl orus needs a pollinator and is more susceptible to the risk of extinction if local disturbances aff ect its pollination system.

Heteranthery, the presence of different types of stamens in a flower, may reduce the conflict between pollinators and plants by ensuring the resource for the pollinator without drastically affecting the availability of viable male gametes for fertilization, according to the division-of-labor hypothesis. We investigated whether the poricidal anthers of Senna pendula, a buzz-pollinated heterantherous species, present morphological and physiological differences among pollen grains from the three sets of stamens. We compared quantity, ornamentation, size and fecundity of pollen from long, medium and short stamens. The short feeding stamens produced larger but fewer pollen grains than the long pollinating stamens, which produced smaller pollen grains but in higher quantity. The total pollen volume of pollinating and feeding stamens per flower, however, was the same. The medium stamen produced lessfertile small pollen grains and seems to play no specific role in bee feeding and pollination. Our results indicate differential allocation of pollen for pollinating and feeding stamens mediated by heteranthery. The differences in volume versus quantity of pollen grains fit the division-of-labor hypothesis well for heterantherous pollen-only flowers with poricidal anthers.

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IntroductionBlueberry is one of the most relevant buzz-pollinated crops worldwide, and Chile is the most important global producer of fresh blueberries during wintertime in the Northern Hemisphere. Non-buzzing bees, such as honey bees, may provide suboptimal services compared with bees capable of buzz pollination. The widely held contention that honey bees are inferior pollinators of blueberries drives the industry to place pressure on governments to allow bumblebee (Bombus terrestris) importation for pollination. However, the introduction of B. terrestris generates environmental problems in Chile by competing with and transmitting parasites to local bees. Despite some native Chilean bees being recently recognized as efficient pollen vectors of blueberry crops, no study has evidenced the influence of their visits on fruit yield. Therefore, we aimed to evaluate the native Chilean floral visitors' performance to improve the quantity and quality of highbush blueberry in comparison to the performance of managed visitors.MethodsPer-visit pollination performance (fruit set and fruit quality) and visitation frequency were measured, and the performance of buzzing behavior by flower visitors was evaluated in four cultivars grown in five blueberry orchards located in southern Chile.ResultsWe found that fruit set and weight were highly influenced by floral visitor taxon. Some native bee species can greatly improve the fruit set and fruit quality (greater weight) of the highbush blueberry cultivars. For instance, one single visit of C. occidentalis can increase fruit weight by a factor of 1.8 compared to an A. mellifera visit; however, visits of halictids and syrphids resulted in lower fruit sets than those of unvisited flowers. However, we found that the occurrence of sonication behavior alone was not a predictor of higher fruit set and fruit weight of highbush blueberry cultivars. Consequently, the taxonomic recognition of floral visitors, ideally to the species level, is still needed to distinguish the most efficient fruit yield promoters of blueberry.DiscussionThe conservation of the biotic pollinators, especially native pollinators, would improve blueberry fruit quality and is likely to improve overall crop productivity.