Embryology of Crawfurdia delavayi (Gentianaceae) and its systematic value

The embryological characters of Crawfurdia delavayi Frabnch. are described and the systematic relationships of Crawfurdia discussed. Anthers are tetra sporangiate. The development of anther walls conforms to the Dicotyledonous type. The tapetum is of single origin. The development of the tapetum with uninucleate cells is of the glandular type. The tapetal cells on the conne ctive side show radial elongation or periclinal division and intrude into t he anther locule. The epidermis of anther walls persists and its cells beco me pillar and fibrous, and the endothecium degenerates. The ovary is bicarp ellary and unilocular. The placentation is typically parietal with 8 rows o f anatropous ovules. The development of embryo sac is of the polygonum type . Before fertilization, two polar nuclei fuse into a secondary nucleus. Thr ee antipodal cells persist. Flowers are protandrous. Fertilization is porog amous. The development of the endosperm is of the nuclear type. The embryog eny corresponds to the solanad type physalis II variation. The embryologica l data indicate that it is better to separate Crawfurdia from Gentiana as a n independent genus.