ABSTRACT We report on the reproductive biology, pollinators, and thermogenesis of the widely distributed Araceae species, Xanthosoma striatipes. We analyzed the floral scent in one population and compared it to a previous study. Xanthosoma striatipes was studied at three sites in Brazil, São Paulo, Minas Gerais and Maranhão. The results showed constancy of the reproductive biology and main pollinator species across sites. The pollinators at all three sites sites were two species of cyclocephaline scarabs, Cyclocephala atricapilla and C. ohausiana. The scent composition of the strongly scented inflorescences of plants of a site in São Paulo differed from plants recently studied in Central Brazil. Of the 39 and 23 compounds detected, in the present and the previous study, respectively, only seven compounds, were in common. We discuss that the two main constituents identified in samples at both sites, the aromatic compound methyl salicylate and the terpenoid (E)-4,8-dimethyl-1,3,7-nonatriene, alone seem to be sufficient for the attraction of the beetles. However, it is also possible that different compounds are involved in attracting the same beetle species to plants of the different populations.

Resumo Uma nova espécie, Annona longipedicellata, da Amazônia Brasileira, está descrita e ilustrada. Ela se distingue de A. hypoglauca e A. scandens, suas espécies mais próximas, por ter pedicelos bem mais longos e uma pubescência ferrugínea densa nas folhas e flores. Alem disso, difere de A. hypoglauca por ser liana.

Abstract A new species of Annonaceae, Annona longipedicellata, from the Brazilian Amazon is described and illustrated. It differs from A. hypoglauca and A. scandens, its closest two species, by much longer pedicels, densely covered red-brown hairs on leaves and flowers and additionally from A. hypoglauca by its habit as liana.

ABSTRACT A comprehensive census of a hectare of cerrado s.s. in southeastern Brazil, a small-tree and scrub woodland physiognomy, allowed the evaluation of whether pollination and dispersal modes are correlated with the stratification of the vegetation and if so, in what way. Generalist pollination, and pollination by small bees, as well as ornithophily and anemophily were more frequent in the lower layers (ground and scrub), while species pollinated by large bees and beetles are more or less equally distributed among the ground, scrub and tree layers. The three nocturnal pollination modes, phalenophily, sphingophily, and chiropterophily indicated a preference for the upper layers (tree and scrub). Zoochory predominated in the tree layer, but autochory increased towards the ground at the expense of anemochory and zoochory. We discuss possible reasons for the height distribution of pollination and seed dispersal modes and compare the situation in Cerrado with other Neotropical forests.

ABSTRACT The feeding of pollinating dynastid-scarab beetles on nutritious tissue of Annonaceae flowers results in macroscopically visible gnawing marks on petals. In the present paper, we present and discuss examples of such gnawing marks on Annonaceae from the Cerrado and the Amazon Forest in Brazil. The localization of gnawing marks on the petals and the histochemistry of the nutritious tissues are emphasized. In some species, nutritious tissue is apparently distributed among all petals, while in other species it is more or less diffusely localized. There are also cases in which nutritious tissue occurs only on clearly localized regions of the inner petals. Petals of selected Amazon species were stained, and studied by light and scanning electron microscopy. The nutritious tissue consists of cells with mucilage-rich walls, which contain starch, lipids and/or tannins. Starch and lipids are not only energy-rich food for the beetles but are apparently also “fuel” for metabolic heating of the flowers, which is a further benefit for the pollinators inside the pollination chamber.

ABSTRACT Data of six studied Neotropical Anaxagorea species are analyzed and discussed with respect to the population structure, flowering phenology, flower morphology, anthesis, scent emission, thermogenesis, floral visitors, breeding system, fruit-set and seed dispersal. The probably reason for the patchy distribution of small populations of Anaxagorea species within lowland tropical forests is given. A novel explanation of the functional significance of ruminate endosperm is presented. Flowering of the species follows either the annual or the continuous flowering pattern. All studied species have diurnal, two-day lasting, protogynous anthesis; several species have thermogenic flowers. Self-compatibility appears to be the prevailing reproductive system in the genus. However, there is a strong tendency for effecting cross-pollination. Floral scent of Anaxagorea species contains fruit-like components, and the pollinators, primarily Nitidulidae (Colopterus spp.) are attracted by deceit. Strong scenting pollination chambers occur also in most other cantharophilous Annonaceae. Novel floral developments are apparent mainly in fly-, cockroach- and bee-pollinated Annonaceae, which have patterns different from cantharophilous species and exhibit open flowers with reflexed petals, which allow their pollinators to reach and touch the reproductive organs.

As flores de Annonaceae são caraterizadas por pétalas carnosas, muitos estames com conectivos duros em forma de escudo e numerosos carpelos com estigmas sésseis que produzem exsudados pegajosos. As pétalas de muitas espécies formam uma câmara de polinização durante a antese. Protoginia e fortes emissões de cheiro, especialmente durante a fase feminina, são características de quase todas as espécies. A maioria das espécies com flores noturnas tem termogênese, o que acelera a emissão de cheiros e fornece um lugar aquecido aos besouros polinizadores. Uma função das pétalas de Anaxagorea e de outras espécies de Annonaceae é a produção de calor através da queima de amido acumulado e da emissão de componentes de cheiro. Apesar de que a maioria de Annonaceae parece ser autocompatível, a dicogamia de certa maneira age contra a autopolinização. A polinização por besouros (a cantarofilia) é o modo predominante na família. O gênero mais basal da familia parece ser Anaxagorea, cujas flores emitem um cheiro composto de ésteres de frutos e àlcool e atraem principalmente pequenos besouros do gênero Colopterus (Nitidulidae), que normalmente vivem em frutos. Pelo fato de que a polinização por besouros é plesiomórfica em Anaxagorea, características associadas com a cantarofilia aparecem em quase todas as espécies de Annonaceae. Tanto as flores de Anaxagorea como as de outros Annonaceae são predadas por besouros e moscas que comem as pétalas e cujas larvas também se criam nas pétalas ou nos óvulos. Portanto, as pétalas carnosas podem ser interpretadas também como estruturas antipredatoras. São demonstrados casos de polinização por besouros pequenos em flores diurnas (p.e. Guatteria, Duguetia, Annona) e por besouros grandes (Dynastinae, Scarabaeidae) em flores noturnas (p.e. Annona, Duguetia). Algumas Annonaceae são adaptadas a uma polinização por trips (Thysanoptera), moscas, baratas a até abelhas. Apesar de que estes grupos de Annonaceae que não são polinizados por besouros possuem adaptações aos seus insetos específicos, eles ainda mostram algumas características cantarofílicas de seus ancestrais.

Flowers of Annonaceae are characterized by fleshy petals, many stamens with hard connective shields and numerous carpels with sessile stigmas often covered by sticky secretions. The petals of many representatives during anthesis form a closed pollination chamber. Protogynous dichogamy with strong scent emissions especially during the pistillate stage is a character of nearly all species. Scent emissions can be enhanced by thermogenesis. The prevailing reproductive system in the family seems to be self-compatibility. The basal genus Anaxagorea besides exhibiting several ancestral morphological characters has also many characters which reappear in other genera. Strong fruit-like scents consisting of fruit-esters and alcohols mainly attract small fruit-beetles (genus Colopterus, Nitidulidae) as pollinators, as well as several other beetles (Curculionidae, Chrysomelidae) and fruit-flies (Drosophilidae), which themselves gnaw on the thick petals or their larvae are petal or ovule predators. The flowers and the thick petals are thus a floral brood substrate for the visitors and the thick petals of Anaxagorea have to be interpreted as an antipredator structure. Another function of the closed thick petals is the production of heat by accumulated starch, which enhances scent emission and provides a warm shelter for the attracted beetles. Insight into floral characters and floral ecology of Anaxagorea, the sister group of the rest of the Annonaceae, is particularly important for understanding functional evolution and diversification of the family as a whole. As beetle pollination (cantharophily) is plesiomorphic in Anaxagorea and in Annonaceae, characters associated with beetle pollination appear imprinted in members of the whole family. Pollination by beetles (cantharophily) is the predominant mode of the majority of species worldwide. Examples are given of diurnal representatives (e.g., Guatteria, Duguetia, Annona) which function on the basis of fruit-imitating flowers attracting mainly fruit-inhabiting nitidulid beetles, as well as nocturnal species (e.g., large-flowered Annona and Duguetia species), which additionally to most of the diurnal species exhibit strong flower warming and provide very thick petal tissues for the voracious dynastid scarab beetles (Dynastinae, Scarabaeidae). Further examples will show that a few Annonaceae have adapted in their pollination also to thrips, flies, cockroaches and even bees. Although this non-beetle pollinated species have adapted in flower structure and scent compounds to their respective insects, they still retain some of the specialized cantharophilous characters of their ancestors.

Parkia pendula ocorre no Brasil, tanto na Amazônia como na Mata Atlântica nordestina. Seus botões, néctar e goma da vagem são recursos chave para a mastofauna da Mata Atlântica nordestina. Para aumentar o conhecimento sobre estes importantes recursos alimentares, este estudo teve como objetivo detectar e descrever as diferentes fases de desenvolvimento de flores e frutos. Este trabalho foi realizado em um fragmento de Mata Atlântica de 306 ha em Igarassu, Pernambuco, Nordeste do Brasil. Entre setembro de 2003 e janeiro de 2004, seis variáveis morfométricas foram medidas semanalmente em cinco inflorescências de dois indivíduos. Onze fases distintas de desenvolvimento puderam ser identificadas e descritas em detalhe nas 21 semanas desde o desenvolvimento das primeiras inflorescências até as vagens maduras. Essas fases são boas preditoras da fenologia de floração e frutificação de P. pendula porque são distinguíveis facilmente do solo da floresta. Além disto, a observação de abortos sincronizados de inflorescências, botões e vagens corrobora a estratégia de defesa previamente sugerida para Parkia, de saciedade de predadores.

Parkia pendula occurs in Brazil in Amazonia and in the northeastern Atlantic Forest. In the latter, its buds, nectar, and seedpod gum are discussed to be keystone resources for the mammalian fauna. To enhance the knowledge about these important nourishment sources, the aim of this study was to detect and describe distinct phases in the flower and pod development. The study was conducted in a 306 ha forest fragment in Igarassu, Pernambuco, northeastern Brazil. Six morphometrical variables were measured weekly at five inflorescences of two individuals from September 2003 to January 2004. Eleven distinct developmental phases were identified in the 21 weeks lasting development from the very first inflorescences to mature pods and are described in detail. These phases are good predictors for the flowering and fruiting phenology of P. pendula, since they are easily distinguishable from the forest floor. Furthermore, highly synchronized abortions of inflorescences, buds, and pods were observed which support the previously assumed predator satiation defense strategy in Parkia.

O presente estudo compara a biologia floral e polinização de espécies de palmeiras e anonáceas que apresentam termogênese. Nos arredores de Manaus (AM) foram estudadas onze espécies de palmeiras pertencentes aos gêneros Astrocaryum, Attalea, Bactris e Oenocarpus e nove espécies de anonáceas dos gêneros Anaxagorea, Duguetia e Xylopia. As palmeiras que apresentam termogênese são monóicas e a antese das inflorescências ocorre em períodos que variam de dois dias até cinco semanas, sempre no período noturno. As flores das espécies de anonáceas são protogínicas com a antese ocorrendo entre dois dias, podendo ser diurna ou noturna. Nos representantes das duas famílias os insetos visitantes são atraídos pelo odor emitido pelas flores que é intensificado através da termogênese. Os odores podem ser agradáveis semelhante ao de frutos maduros ou desagradáveis e pungentes. Os insetos visitantes em sua maioria são coleópteros das famílias Scarabaeidae, Nitidulidae, Staphylinidae, Curculionidae e Chrysomelidae, trips e moscas Drosophilidae. Além desses, as flores das palmeiras são visitadas por abelhas, vespas, formigas e moscas. Na área estudada, a polinização por coleópteros foi o modo mais freqüente das espécies de palmeiras e anonáceas com termogênese. É notável que algumas espécies das duas famílias são visitadas pelas mesmas famílias, e inclusive espécies de coleópteros. Supõe-se que adaptações morfológicas e fisiológicas similares na biologia floral das duas famílias, inclusive dos componentes odoríferos sejam responsáveis por essa atração.

The present study is a comparison of the flower biology and pollination of some thermogenic species of palms and Annonaceae. In the palms eleven representatives of the genera Astrocaryum, Attalea, Bactris, and Oenocarpus, and in the Annonaceae nine representatives of the genera Anaxagorea, Duguetia, and Xylopia were studied in the region of Manaus (AM). All the studied palm species are monoecious and the anthesis of their inflorescences occurs at night during a period which varies from two days to five weeks. The investigated species of the Annonaceae are protogynous with the anthesis of a single flower lasting for two days and occurring at night or during the day. Flower visiting insects are attracted by strong odours which are intensified through thermogenesis. The species-specific odours range from fruit-like to unpleasant and pungent. Most of the flower visiting insects are beetles of the families Scarabaeidae, Nitidulidae, Staphylinidae, Curculionidae, and Chrysomelidae, and additionally thrips and drosophilid flies. Further insects which visit the flowers are bees, wasps, ants, and other fly groups. However, palms and Annonaceae with thermogenic flowers most frequently showed beetle pollination. It is notable that flowers of some species of both families were visited bythe same families and even species of beetles, which might be due to similar morphological and physiological adaptations of the flowers, including production of similar odour components.