Flowers, fruits, seeds and seedlings morphology of Sacaca Croton cajucara Benth. (Euphorbiaceae).

摘要

The objective of this work was to morphologically characterize the reproductive organs of sacaca (C. cajucara), a medicinal and aromatic plant of the Amazon. The inflorescences, flowers, fruits, germination and seedlings were characterized. The inflorescences are racemes of 9.0 cm in length, with 7 female flowers in the base and 12 male flowers at the median and terminal portion of the raceme. The female flowers are pentamerous, monoperianthial, with a quincuncial prefloration, and hypogynous. Thegynoecium consists of three carpels, three ovules, with a superior sericeous ovary, concrescent probes and a multifid stigma. The male flower has two perianths and is pentamerous, simple and valvar. The androecium is polystemonous. The inflorescences andfloral parts are pubescent. The fruit is dry dehiscent, tricocid, with a loculicidal capsule, and carpels containing one seed each. The fruit is 7.7-9.0 mm long and 7.9-9.5 mm wide, globose. The seed is oblong-sharp and bitegmented. The testa is black,glabrous, brilliant and albuminous. The hilum is punctiforme placed in the protuberance of the basal extremity and associated with a bilobed caruncula; 3.76-4.67 mm long, 2.3-3.0 mm wide and 2.0-2.8 mm thick (medium). The embryo has a sharp radicle and arudimentary plumule between the thin cotyledons. The germination is epigeal. After 4 days of germination, the hypocotyl form a loop and after 7 days, it elevated the cotyledons. At 10 days, the cotyledons, ovoid and petiolated, opened horizontally. At 15 days, a leaf was present. At 30 days, two alternating leaves were observed. At 51 days, the plant possessed a teretiform caulicle with a greenish pubescence, with 4 alternating simple leaves, which were lanceolate, petiolate and pubescent only on the dorsal surface and glabrous on the ventral surface. The pubescence was in the main nervure. The hypocotyl measured 9.0 cm in length.