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MORFOLOGIA DE FRUTO, SEMENTE E PLÂNTULA DE Sebastiania commersoniana, EUPHORBIACEAE
This work consists on a morphological description of the fruit, seed and seedling of Sebastiania commersoniana (Baillon) L. B. Smith & R. J. Downs (branquilho), tree species with wide distribution in southern Brazil, especially in the floodplains of the Mixed Ombrophylous Forest. For this, they were obtained fruits of ten trees in the district of Engenheiro Bley, municipality of Lapa-PR. For description and illustration of the fruits and seeds, 50 random samples were used. For germination, seeds were placed on paper-towel and on commercial substrate, in Biomatic germinator, at 25 ºC. S. commersoniana has a dehiscent schizocarpic fruit, with three fruitlets. The albuminous seed has a papyraceous seed coat with caruncle, hilum, raphe and micropyle visible under magnifying glass. The embryo is dominant, axial, espatulate, with cordate, foliaceous cotyledons and cylindrical axis. The germination started up around the third and fourth days after the test installation and the seedling is epigeal, phanerocotyledonous. The opening of the paracotyledons and the beginning of the epicotyl development occurred about 15 days after the test installation. Several characteristics described in this paper explains, in part, the efficient and expressive distribution of this species in its area of natural occurrence.Neste estudo, realizou-se a descrição morfológica de fruto, semente e plântula de Sebastiania commersoniana (Baillon) L. B. Smith & R. J. Downs (branquilho), espécie arbórea de ampla distribuição no sul do Brasil, especialmente nas planícies aluviais da Floresta Ombrófila Mista. Foram obtidos frutos de dez matrizes em Engenheiro Bley, distrito da Lapa-PR. Para a descrição e ilustração do fruto e da semente, 50 amostras aleatórias foram analisadas. As sementes foram colocadas em rolo de papel-toalha, e em substrato comercial, postas para germinar em germinador Biomatic, a 25 oC. A espécie tem fruto deiscente do tipo esquizocarpáceo tricoca. A semente é carunculada, com hilo, rafe e micrópila visíveis sob lupa, tegumento papiráceo e endosperma oleaginoso, tendo dispersão autocórica e zoocórica. O embrião é dominante, axial, espatulado, com cotilédones foliáceos, cordiformes e eixo hipocótilo-radicular cilíndrico. A germinação iniciou-se por volta do terceiro e quarto dias após a instalação do teste, sendo a plântula epígea, fanerocotiledonar. Decorreram cerca de dez dias até a abertura dos paracotilédones e 15 dias até o início do desenvolvimento do epicótilo. Diversas características aqui descritas explicam, em parte, a eficiente e expressiva distribuição da espécie em sua área de ocorrência natural. Palavras-chave: Morfologia vegetal; germinação; floresta aluvial; floresta ciliar. Abstract Morphology of the fruit, seed and seedling of Sebastiania commersoniana, Euphorbiaceae. This work consists on a morphological description of the fruit, seed and seedling of Sebastiania commersoniana (Baillon) L. B. Smith & R. J. Downs (branquilho), tree species with wide distribution in southern Brazil, especially in the floodplains of the Mixed Ombrophylous Forest. For this, they were obtained fruits of ten trees in the district of Engenheiro Bley, municipality of Lapa-PR. For description and illustration of the fruits and seeds, 50 random samples were used. For germination, seeds were placed on paper-towel and on commercial substrate, in Biomatic germinator, at 25 ºC. S. commersoniana has a dehiscent schizocarpic fruit, with three fruitlets. The albuminous seed has a papyraceous seed coat with caruncle, hilum, raphe and micropyle visible under magnifying glass. The embryo is dominant, axial, espatulate, with cordate, foliaceous cotyledons and cylindrical axis. The germination started up around the third and fourth days after the test installation and the seedling is epigeal, phanerocotyledonous. The opening of the paracotyledons and the beginning of the epicotyl development occurred about 15 days after the test installation. Several characteristics described in this paper explains, in part, the efficient and expressive distribution of this species in its area of natural occurrence.Keywords: Plant morphology; germination; alluvial forest; riparian forest