Evolutionary history of plants seed model is shared by basically all gymnosperms (literally: "naked seeds"), most of which encase their seeds in a woody cone or fleshy aril (the yew, for example), but none of which fully enclose their seeds. The angiosperms ("vessel seeds") are the only group to fully enclose the seed, in a carpel. Fully enclosed seeds opened up a new pathway for plants to follow: that of seed dormancy. The embryo, completely isolated from the external atmosphere and hence protected from desiccation, could survive some years of drought before germinating. Gymnosperm seeds from the Late Carboniferous have been found to contain
Native Seeds/SEARCH grant to pursue his studies of the agronomic characteristics and health value of desert food plants, including in relation to controlling diabetes among Indians and Hispanic Americans. As of 2016, the Native Seeds/SEARCH seed bank contained seeds from over 1800 plant varieties. In addition to a seed bank, Native Seeds/SEARCH opened a conservation farm in 1997. Seeds are distributed by mail order and a retail store in Tucson. Since 2001, Native Seeds/SEARCH has operated Southwest Regis-Tree to conserve Native Southwestern perennial species. Native Seeds/SEARCH Native Seeds/SEARCH, founded in 1983, is a nonprofit conservation organization located in Tucson, Arizona in the