The stigma plays several roles such as pollen hydration and selection, and pollen tube nutrition. In the Ficus-fig wasp mutualism, stigmata have an additional, almost unknown, function by representing a physical interface for both plant and wasp reproduction. We used light and electron microscopy to compare the detailed morphology of the stigmata of nine Ficus species of different sections and with different pollination modes and sexual expressions. Figs were collected at the stage when the stigmata were receptive for pollination. Stigmata in actively pollinated monoecious species have well developed papillae concentrated on the adaxial surface exposed towards the fig cavity. Conversely, the passively pollinated monoecious species have the whole surface of the stigmata covered by somewhat smaller papillae. In both actively and passively pollinated monoecious species these features are consistent, irrespective of style length. In all actively pollinated gynodioecious species, the stigmata of pistillate flowers were tubular or infundibuliform whereas in almost all actively pollinated monoecious species (except F. racemosa) the stigmata were filiform, with one branch or two asymmetric branches. In gynodioecious species the short-styled flowers in "male" figs show a limited receptive surface with small papillae, while the stigmata of long-styled flowers in "female" figs are covered by papillae that extend down the sides of the style, increasing the stigmatic surface. In actively pollinated species, stigmata are cohesive, forming a common surface for pollen tube germination (= synstigma). The synstigma arrangement was quite variable: lax, cohesive or very cohesive, with entanglement by stigmatic papillae and stylar trichomes. Entanglement by stylar trichomes is common in gynodioecious species. The synstigma arrangement did not correlate with phylogeny or breeding system. This study is the first to report a very loose synstigma in actively pollinated monoecious Ficus species. Our analyses revealed that, in Ficus, the synstigma is functionally analogous to an extra-gynoecial compitum. Comparative studies will be required to test further hypotheses about the evolutionary determinants of such variation.

No abstract

-(Leaf anatomy with taxonomic implications in "ipê" species). By considering that Brazilian species of Ipês are hardly identifi ed when in vegetative stage, the present study aims to research foliar anatomic characters that might allow recognize medicinal ipê species. Leaves of six species of Handroanthus (yellow fl owers: H. chrysotrichus, H. ochraceus and H. serratifolius; white fl owers: H. roseo-albus; purple fl owers: H. heptaphyllus and H. impetiginosus) and one species of Tabebuia (yellow fl owers: T. aurea) were prepared to be observed with light microscopy (free-hand cuts), and scanning electronic microscopy (surface analysis). Foliar anatomical characters allow recognizing Ipê species. The better ones provided by foliar lamina were the number of epidermic layers, the stomata position in relation to the other epidermic cells, the occurrence of domatia, the parechymatic cell wall thickening in the margin, the mesophyll type and the presence of paraveinal parenchyma; in the petiole, we can cite the petiole shape, the epidermic cell shape and the occurrence of inner phloematic fi bers. Key words: Bignoniaceae, diagnostic character, Handroanthus, Tabebuia RESUMO -(Anatomia foliar com implicações taxonômicas em espécies de ipês). Tendo em vista a difi culdade de identifi cação dos ipês brasileiros em estado vegetativo, este trabalho objetivou levantar caracteres que possibilitassem reconhecê-los pela anatomia foliar (lâmina foliar e pecíolo). Folhas de seis espécies de Handroanthus (ipês amarelos: H. chrysotrichus, H. ochraceus e H. serratifolius; ipê branco: H. roseo-albus; ipês roxos: H. heptaphyllus e H. impetiginosus) e de uma espécie de Tabebuia (ipês amarelo: T. aurea) foram preparadas para observação em microscopias de luz (exame histológico) e eletrônica de varredura (exame de superfície). Caracteres provenientes da anatomia foliar possibilitaram a diagnose dos ipês, sendo mais relevantes na lâmina foliar, o número de camadas da epiderme, a posição dos estômatos em relação às demais células epidérmicas, a presença de domácias, a presença de espessamento de parede das células parenquimáticas na margem, o tipo de mesofi lo e a presença de parênquima paravenal; no pecíolo, destacaram-se seu formato, a forma das células epidérmicas e a presença de fi bras na região interna do fl oema.