1. Maydeae.
2. Spikelets bisexual, or male and bisexual, each male standing close to a bisexual.
2. Andropogoneae.
β Fertile glume and pale cartilaginous, coriaceous or papery; empty glumes more delicate, usually herbaceous, the lowest usually smallest. Spikelets falling singly from the unjointed rachis of the spike or the ultimate branches of the panicle.
3. Paniceae.
b. Hilum a line; spikelets laterally compressed.
4. Oryzeae.
B. Spikelets one- to indefinite-flowered; in the one-flowered the rachilla frequently produced beyond the flower; rachilla generally jointed above the empty glumes, which remain after the fruiting glumes have fallen. When more than one-flowered, distinct internodes are developed between the flowers.
a. Culm herbaceous, annual; leaf-blade sessile, and not jointed to the sheath.
α Spikelets upon distinct pedicels and arranged in panicles or racemes.