GRASSES. 127 
and two inner bracts or glumels ; but while in Agrostis the inferior 
of the inner bracts bears the awn either below its summit or is 
destitute of an arista altogether, it will be noticed, that in Stipa 
the corresponding organ carries the awn terminally and by an 
articular insertion. As a general rule the bracts and awns of the 
species of Agrostis 
are much smaller 
and shorter than 
those of a Stipa. 
Aristida differs from 
the latter genus in 
nothing essentially 
but atrifidawn. One 
of the most universal 
of all our grasses is 
the Danthonia peni- 
cillata, which dis- 
plays an extraordi- 
nary versatility of 
forms. This genus 
was named in honor 
of E. Danthoine 
of Marseilles. The 
structure of the 
flowers is formed on 
the plan of a Fescue, 
but the lowest pair 
of bracts is far the 
longest, the outer 
bract of each floret is 
bearded at the base 
as well as middle, 
and terminated by 
two short lateral Fie. LVI.—(Ehrharta stipoides)—1, base of leaf 
awns and one elonga- and summit of leafstalk ; 2,a complete flower ; 3, flower, 
: : the lower bracts removed ; 4, inner bracts ; 5, anthers ; 
ted terminal twisted 6, pollen-grains ; 7, pistil with sepaline scales; 8, se- 
awn. It would lead paline scales ; 5-8, much magnified. 
