43 
Trine VI.—ORYZESX. 
Spikelets amy much ie laterally, 1-flowered, stam- 
fata pistillate ermaphrodite; empty glumes 2 or none, the 
er being su edad by the floral glume and palea stain the 
ae I-nerved and regarded by some as a second glume; stamens 
frequently 6; axis of the inflorescence not articulated. 
A small tribe of about forty species divided among 
sixteen genera, mostly confined to tropical America. 
One of the best known and most extensively used of 
the cereals, rice (Oryza sativa), belongs here. 
KEY TO THE GENERA OF THE ORYZE-F. 
|. Spikelets unisexual, plants monceciov 2 
1. Spikelets hermaphrodite, bcnety sasha Rie Sli a 6 
2. Inflores of terminal and axillary spikes, efi former pedun- 
culate and staminate, the latter sessile and pistillate. 
HypRocHLoA 
2. Inflorescence paniculate 
a5 
ted 
Spikelets in pairs, the — large and sessile, the staminate 
small and pedicellat 30. PHarus 
. Spikelets not in pairs 4 
we 
4. spores: and pistillate spikelets in separate panicles or in the 
icle when the staminate are terminal.. 31. LuzioLa 
: Sinrattine and pistillate spikelets in the same panicle, the pis- 
tillate above, the staminate below 5 
oh 
5. Fruiting spikelets narrow, subterete, caryopsis sia . 
33. ZIZANIA 
5. poi spikelets subeompressed, caryopsis ovate. 
32. ZIZANIOPSIS 
= 
Empty glumes two, flowering glume often awned.. 34. Oryza 
Empty glumes none, flowering glume awnless. 
35 
> 
. HomMALocENCcHRUS 
