Studies on Sexual Organs and Embryological Development Morphology of Speirantha gardenii (Convallariaceae)
白穗花有性器官与胚胎发育形态的研究

We investigated the embryological characters of Speirantha gardenii (Hook.) Baill.(Convallariaceae). The anther has 4 sporangiates and a glandular tapetum. Meiosis of the microspore mother cells was accompanied by successive cytokinesis, for the formation of mostly an isobilateral tetrad. Occasionally linear, T-shaped and decussate microspore tetrads were observed. The mature pollen grains were 2 celled. The ovary was trilocular with axile placentation and anatropous, biteguminous and crassinucellate ovules. The micropyle was formed by the inner integument. The development of the embryo sac conformed to the Polygonum type. The embryogeny belongs to the Onagrad type, and endosperm development as the nuclear type. Comparison with other studied species in Convallarieae revealed that (1) Speirantha and Aspidistra may have a common ancestor and (2) Theropogon may be an alien in the tribe.