GRIFFITHS—THE GRAMA GRASSES. 349 
This is not the method followed in some of the recent literature of 
the grasses, and it is in no closer accord with recent practice than is 
the comprehension in one genus of all the species here included. 
Kunth? was the first excessively to divide the group, and to some 
extent his work has been adopted by some recent authors. Others 
have contented themselves with adopting Kunth’s genera as sub- 
genera or sections. Were I to divide the genus, however, the lines 
laid down by Kunth would have to be somewhat modified as has 
been done by Nash.’ Kunth includes in Dinebra Bouteloua curti- 
pendula and B. aristidoides as well as B. radicosa, B. repens, and B. 
chondrosioides, while for Aristida americana of Linneus, the West 
Indian representative of our B. filiformis, which is a variant very 
close indeed to that species, the monotypic genus Heterostega of 
Desvaux was adopted. The other monotypic genus, Polyodon H. B. 
K., should also, without doubt, be included with the radicosa-repens 
section of the genus to which Kunth applied the name Dinebra Jacq. 
Chondrosium on the contrary is better delimited and could stand on 
its merits without change better than the others. 
Although Kunth formally recognized all these genera it was against 
his best judgment that this was done. He specifically states that 
in his opinion these genera should be united. The disposition made 
here was decided upon before the opinion of Kunth was discovered. 
His opinion ¢ corresponds very closely indeed with my own preference. 
There has been much difference of opinion as to the relationship of 
Cathestecum ever since it was established by Presl.¢ By Bentham 
and Hooker it was placed in the Zoysieae along with Aegopogon, 
which closely resembles some species of Bouteloua and probably 
should stand closer to that genus than it is now placed. By Hackel 
Cathestecum is included in the Festuceae. But the species of this 
genus in general aspect as well as in minuter details very closely 
resemble some species of Bouteloua. The resemblance in the field 
is so great that botanists usually refer their collections of Cathes- 
tecum to Bouteloua. 
The group differs from the remainder of the grama grasses in hav- 
ing 3 spikelets in the spike, in the reduction of the first glume in one 
or all of the spikelets, and in a tendency to multiplication of awns 
by division of the nerves of the lemma of the upper florets. 
aH, B, K. Nov. Gen. & Sp. 1: 171-176. 1816. 
bSmall, Fl, Southeast. U. 8. 137. 1903. 
cH. B. K. Nov. Gen. & Sp. 1: 173. 1816. The last paragraph on the page reads 
as follows: ‘‘Heterostega vix genus distinctum, habitus Dinebrae, characteres Chon- 
drosii; genera Heterostegae, Chondrosii et Polyodontis, ut mea fert opinio, valde 
artificialia, et aptius generi Dinebrae conjungenda sunt.” : 
@Rel. Haenk. 1: 295. pl. 42. 1830. 
