The orchid family has over 880 different types (called genera) and over 22,000 species. These numbers are growing every year making orchids the largest and most diverse of the flowing plant families. In general Orchids are largely tropical plants which live as epiphytes or "air plants" hanging...
Before fertilization, the outer integument is still growing (Fig. 3B, C). It has not enclosed the embryo sac completely. At this stage, the walls of the outer seed coat cell are relatively thin (Fig. 3C). After fertilization, the walls of the outermost layer of the seed coat become ...