CHARACTERIZATION OF SEEDS AND SEEDLINGS OF ZEPHYRANTHES BIFIDA (AMARYLLIDACEAE).

Background and aims: Zephyranthes bifida is a native species of the Pampas ecoregion, with ornamental and medicinal potential. In this work, the seedling was studied for the first time and its seeds were characterized. The objectives were to describe the cotyledon and the first leaf and to provide some anatomical characteristics, as well as to provide information about the embryo/endosperm relationship and the type of reserve substances in the seed. M&M: Seed reserve substances were determined by histochemical tests and the embryo/endosperm surface ratio was obtained with ImageJ. In seedlings, morphological structures were described, using Tillich's terminology (1995; 2007), and some anatomical characteristics. Phenological stages were established for ten days from germination. Results and conclusions: Lipid and protein and lack of starch were determined in embryo and endosperm. In seedlings, the cotyledon is subdivided into a hypophyll and a hyperphyll. Hypophyll presents a ring through which the first eophyll emerges. The distal part of the cotyledonary hyperphyll is completely inserted in the seed, has a haustorial function and has two vascular bundles. Proximal part of cotyledonary hyperphyll has photosynthetic activity and has two vascular bundles too. In the first eophyll, hyperphyll has three vascular bundles. The primary root is attached to the base of the cotyledon through a very short hypocotyl, which in its basal part has rhizoids. Four stages were defined during germination from the emergence of hypophyll, hyperphyll and first eophyll. [ABSTRACT FROM AUTHOR]