G45 

 OATGRASSES 



Dantho'nia spp., syn. Merathrep'ta spp. 



The North American representatives of Danthonia^ of which seven 

 species are now recognized by the more conservative botanists as 

 occurring in the United States, are all perennial bunchgrasses. Six 

 of these species are found in the western States. Other species, both 

 of annuals and perennials, are abundant and widely distributed in 

 warm and temperate regions in other parts of the world, especially 

 in South Africa and Australia, where the genus is very important. 

 Danthonia belongs to the oat tribe of grasses (Aveneae) and was 

 named for Etienne Danthoine, a French botanist of the eighteenth 

 century. It is a bit unfortunate that the common name, oat-grass, 

 has become so firmly intrenched in western range usage for this 

 genus, as the western species show no great resemblance to oats 

 (Avena spp.) and the name, tall oatgrass, is well established for 

 a species in another genus, Arrenatherum elatius. 



All western danthonias, except poverty oatgrass (D. spicata, syn. 

 D. thermalis), are at least fairly palatable to livestock. Poverty 

 oatgrass can be recognized at any time of the year by its short, very 

 curly leaves. It is well named, as it is an excellent indicator of poor 

 soil and also is worthless as forage; no living thing, except perhaps 

 meadow mice, will eat it unless forced to do so. Flatstem oatgrass 

 (D, compressa) is chiefly an eastern species and not important in 

 the West. Parry oatgrass (D. parryi) is of scattered occurrence 

 and hence often unimportant as a range plant but may be abundant 

 locally. One-spike oatgrass (D. uaiispicata) , California oatgrass (D. 

 calif ornica) , and timber oatgrass (D. intermedia) are sometimes 

 locally abundant and of greater or less importance as range plants. 



The individual flower groups, or spikelets, are about 4- to 10- 

 flowered in the western species of oatgrass, with the lowest (2) 

 spikelet bracts (glumes) much longer than the outer flowering bracts 

 (lemmas), and commonly as long as the spikelet. The lemmas are 

 2-toothed and bear a stiff, bent, usually twisted beard (awn) from 

 between the teeth. All the western species have large, hidden, self- 

 fertilizing spikelets (cleistogenes) at the lower joints of the stems 

 and enclosed by the leaf sheaths. These spikelets mature seed, and 

 the stems commonly break off at the joints where the spikelets are 

 borne. 



