4 
5. Tribe ORYZE A. 
Spikelets perfect or unisexual, 1-flowered ; flowers apparently termi- 
nal and inclosed by a flowering glume and a palet, which is usually 
l-nerved. Empty glumes 2 or more, very seldom numerous. Stamens 
frequently 6, sometimes more. Stigmas more or less elongated ; fruit 
with a small embryo and a long linear hilum. 
A. Spikelets unisexual ; planta monecious ; anthers 6 or more. 
I. Spikelets in short, solitary spikes, terminal and axillary .... HYDROCHLOA, 40 
II. Spikelets in panicles, not in pairs at the nodes of the panicle, without empty 
glumes. 
* Female spikelets ovate or elliptical; embryo many times longer than the 
fruit. 
+ Male and female spikelets in different panicles, rarely in the same, and then 
the male spikelets terminal on each branch..-..........---- Luzioua, 40 
+ Male and female spikelets in the same panicle, the female terminal, the 
male at the base of each branch...-..--...---.----..----- ZIZANIOPSIS, 41 
II. Spikelets linear; embryo as long as the fruit; the upper branches female, 
the lower male. .-..-- ..2eee . 2 eens cece cone ne ween eee eee cannes ZIZANIA, 41 
B. Spikelets all perfect ; arranged in panicles, 
I. Empty glumes 2, short but distinet, awnless; flowering glume and palet much 
compressed laterally ........-.. 0.02.20 eee ee cece ee eee cee eee ORYZA, 41 
LU. Empty glumes wanting or only minute rudiments; flowering glumes awn- 
less .......--.-. fee cree eee cement eee cee e ne cee es ees LEERSIA, 41 
6. Tribe PHALARIDEAS, 
Spikelets with 1 perfect terminal flower, with the addition of 2 male 
or imperfect ones, or 1 or 2 sterile glumes or pedicels below the per- 
fect flower and above the lower pair of empty glumes. Rachilla not 
prolonged beyond the fertile flower. Palet or its substitute, with a 
central nerve or none, laterally compressed. 
A. A pair of small glumes or bracts, 1 on each side of the perfect flower. 
PHALARIS, 42 
B. Perfect flower small; on each side an awned empty glume, which is larger 
than the perfect flower ..............2....0-2. ----- ANTHOXANTHUM, 43 
C. Third and fourth glumes, or at least the third, with a male flower almost 
equaling the first and second, awnless or short awned..... HIEROCHLOE, 43 
7. Tribe AGROSTIDEA. 
Spikelets 1-flowered, sometimes with a rachilla or rudiment of a second 
flower, very rarely 2-flowered; empty glumes 2, very rarely wanting, 
usually as long as, or sometimes shorter, or even longer than the floral 
glumes; palet 2-nerved. 
(1) Subtribe STIpPE.z. 
Flowering glume indurated at maturity or at least firmer in texture 
than the empty glumes, very closely inclosing the flowers and fruit, and 
(except in Milium) with a simple or trifid awn from the apex, and (ex- 
cept in Milium) with a callus at the base. 
