THE 
AMERICAN NATURALIST. 




Vor. XXXIX. June, 1905. No. 462. 

FOSSIL GRASSES AND SEDGES.! 
EDWARD W. BERRY. 
IN number of species the Glumales (Graminales, Poales) is 
one of the greatest angiospermous alliances. Aside from the 
forms known as weeds or the cultivated species which have been 
generally distributed by commerce and colonization, the group is 
cosmopolitan, with common species in the northern and southern 
as well as the eastern and western hemispheres. The distribu- 
tion is very uniform, no one tribe or large genus being confined 
toa single geographic area, abundant proof in itself that the 
Glumales are an old type, whose generic evolution occurred far 
back in geological history. 
The known geological record does not, however, throw much 
light on this subject. From the nature of the case the most we 
can expect of fossil grasses and sedges is that they will give us 
some idea when these types first appeared on the globe and when 
they became abundant and widespread. We cannot expect to 
unravel the botanical affinities of stray bits of leaf or indefinite 
remains of inflorescence (Panicum), culms (Culmites), or rhi- 
zomes (Rhizocaulon) in plants whose leaf-form and general struc- 
! Published by permission of the Maryland Geological Survey. 
345 
