25 
Tree I1I.—OSTERDAMI&. 
Spikelets solitary or in groups of 2 to 8, each group falling as 
whole from the continuous rachis, usually 1-flowered, aed 
dite, or staminate and hermaphrodite in the same group; flowering 
glume less firm in texture than the awned or awnless outer ones, 
which are herbaceous, chartaceous, or coriaceous; the first glume 
is usually larger than the second. 
A small tribe, numbering about 25 species, which 
represent nearly half that number of genera. Fifteen 
species are natives of the tropical and warmer temper-— 
ate regions of America. Black grama, or Ga/leta, of 
the Mexicans, is our best-known representative of the 
tribe. 
KEY TO THE GENERA OF THE OSTERDAML#. 
= 
. Spikelets solitary, empty glume one, coriaceous, aw pe 
1: 
a 
. Spikelets in clusters of from three to several at each Anes ‘a th 
main axis, empty glumes two 
2. rae empty glume coriaceous with hooked spines on the 
16. ae 
2 ee empty glume without hooked spines on the back... -- 
oo 
. Spikelets secund along the main axis, the lower spikelets in 
ach group sterile 15. 
Spikelets not secund along the main axis, the two lower or 
outer spikelets 2-flowered and staminate......-. 14. Hivaria 
Bs 
