Morphology of the fruit, seed and seedling of Sebastiania commersoniana, Euphorbiaceae.

Abstract

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.