Underground Organs of the Seedlings and the Systematics of Gramineae

The features of the underground organs of the seedlings have been examined in 219 species of 88 genera of the Gramineae. Six types have been recognized according to the morphology of the underground organs, and seven types have also been acknowledged in the mode of establishment of the seedlings. The features of the underground seminal organs have been symbolized in a formula with a combination of these types. Species of the same genus almost always have identical formulas, and the genera of the same tribe are usually closely related in the features of the underground seminal organs. When the features of the above-ground plantlet are combined with those of the underground organs, the grass seedling can be classified into six groups. They are bambusoid, oryzoid, festucoid, arundinoid, eragrostoid, and panicoid, all of which are often treated as subfamilies in modern grass systematics. It is pointed out that further studies should be made on the seedlings of the tribes Centotheceae and Ehrharteae. The evolution of grass seedlings is discussed.