ABSTRACT This work aimed to morphologically characterize 22 species of Spermacoceae s.s found in the Atlantic Forest in the state of Rio de Janeiro with the purpose of improving palynological knowledge of the studied species. The studied species included six species of Borreria and Denscantia cymosa, Emmeorhiza umbellata, Hexasepalum apiculatum, H. radula, H. teres, Manettia fimbriata, Mitracarpus eichleri, M. frigidus, M. hirtus, M. lhotzkyanus, M. megapotamicus, Oldenlandia salzmannii, Pentodon pentandrus, Richardia brasiliensis, Richardia scabra and Spermacoce rubescens. Acetolysed pollen grains were analyzed using light (LM) and scanning electron miscroscopy (SEM). The pollen grains varied in size (polar diameter) from medium to large, with the exception of Hexasepalum teres which was very large. Pollen grains were oblate spheroidal in most species, suboblate in six species, prolate spheroidal in Spermacoce rubescens and subprolate in Manettia fimbriata. All pollen grains were colporate, while number of apertures varied (three-19). The endoaperture was lolongate in most species and lalongate in four species. Sexine ornamentation varied among reticulate, reticulate-granulate, microreticulate, granulate with perforation, echinate-perforate and vermiculate. Pollen attributes were found to distinguish the studied species, but do not separate genera, confirming that Spermacoceae is euripolynic.

RESUMO A presente revisão do gênero Curtia (Gentianaceae) a qual inclui chave de identificação, descrições, ilustrações e sinônimos, reconheceu oito espécies: C. ayangannae, C. conferta, C. diffusa, C. obtusifolia, C. quadrifolia, C. tenella, C. tenuifolia e C. verticillaris. Curtia é um gênero neotropical, tendo o Brasil como seu centro de diversidade. Curtia tenella e C. tenuifolia têm ampla distribuição geográfica, ocorrendo nas Américas Central e do Sul, C. obtusifolia e C. quadrifolia concentram-se na região amazônica e C. ayangannae está restrita à Guiana. As demais espécies ocorrem no Brasil, distribuídas desde a Região Nordeste até a Região Sul. A distilia foi confirmada em C. obtusifolia e a tristilia em C. tenuifolia.

ABSTRACT The current revision of the genus Curtia (Gentianaceae), which includes a key for identification, descriptions, illustrations and synonyms, recognized eight species: C. ayangannae, C. conferta, C. diffusa, C. obtusifolia, C. quadrifolia, C. tenella, C. tenuifolia, and C. verticillaris. The genus is Neotropical with its diversity center in Brazil. Curtia tenuifolia and C. tenella have wide geographic distribution, occurring in Central and South America, C. obtusifolia and C. quadrifolia are concentrated in the Amazonian region, and C. Ayangannae is restricted to Guyana. The other species occur in Brazil, from the Northeast to the South Region. Curtia obtusifolia has been confirmed as a distylous species and C. tenuifolia as a tristylous species.

Estudou-se a morfologia polínica de Curtia Cham. & Schltdl. e Hockinia Gardner (Gentianaceae Juss.), gêneros neotropicais de Gentianaceae. Foram analisadas oito espécies: Curtia conferta (Mart.) Knobl., C. diffusa (Mart.) Cham., C. obtusifolia (Spruce ex Benth.) Knobl., C. patula (Mart.) Knobl., C. quadrifolia Maguire, C. tenella (Mart.) Cham., C. verticillaris (Sprengel) Knobl. e Hockinia montana Gardner. Os grãos de pólen foram tratados pelo método ACLAC, analisados em microscopia óptica e microscopia eletrônica de varredura. A investigação baseou-se em material herborizado. A heterostilia foi confirmada em Curtia obtusifolia, C. patula e Hockinia montana. O material polínico de todas as formas heterostílicas foi estudado separadamente. Os gêneros apresentaram grãos de pólen pequenos a médios, em mônades, colporados, sexina microrreticulada, microrreticulado-espinulosa, reticulada, reticulado-espinulosa ou perfurada. Os resultados mostraram certa heterogeneidade polínica para o gênero Curtia e foram observadas diferenças palinológicas, quanto ao tamanho, à ornamentação da exina e às aberturas entre as formas florais de cada espécie heterostílica. Os dois gêneros não demonstraram diferenças palinológicas significantes que os separem.

The pollen morphology of the neotropical genera Curtia Cham. & Schltdl. and Hockinia Gardner (Gentianaceae Juss.) was here studied. Eight species have been analyzed: Curtia conferta (Mart.) Knobl., C. diffusa (Mart.) Cham., C. obtusifolia (Spruce ex Benth.) Knobl., C. patula (Mart.) Knobl., C. quadrifolia Maguire, C. tenella (Mart.) Cham., C. verticillaris (Sprengel) Knobl. and Hockinia montana Gardner. The pollen grains were prepared by the ACLAC method, analyzed in scanning electron microscope and light microscope. The investigation is based on herbarium material. The heterostyly was confirmed in Curtia obtusifolia, C. patula and Hockinia montana Gardner. The pollen material of every heterostylous forms was studied separately. The genera presented pollen grains small or medium, in monads; colparates, isopolars; sexine microrreticulate, microrreticulate-spinulose, reticulate, reticulate spinulose or perforate. The results demonstrated certain heterogeneity in the Curtia and, were observed palynological differences, in size, exine ornamentation and apertures, between floral morphs of every heterostylous species. The two genera showed no palynological differences useful to identify them both.