2(1). Glumes equal, 1 mm or more longer than fertile floret; 2 (occasionally 1) scale-like rudimentary florets below fertile floret; disarticulation below glumes; upper floret coriaceous Phalaris
glumes (Hitchcock 1951)
2. Glumes unequal (rarely equal) or only second glume present (in some species of Axonopus, Digitaria and Paspalum); if equal then reduced floret as long as spikelet; disarticulation below the glumes; upper floret usually firm to indurate (except in Pennisetum and Cenchrus) 3