MR. G. BENTHAM ON GRAMINE X. 125 
Poa notwithstanding the adherence of the grain to the palea. 
Leucopoa, Griseb., is the temperate-Asiatie P. albida, Turez., 
with the spikelets rather larger than usual, and somewhat sca- 
riose and shining glumes like those of several Chilian species. 
Dioicopoa, E. Desv. (Dispar, Doell), is a section proposed for 
P. chilensis, Trin., P. lanuginosa, Poir., and their allies, in which 
the spikelets are usually, but perhaps not always, dicecious. In 
the dried state there is very little external difference between 
the male and the female panicle ; and there are certainly Chilian 
specimens otherwise very near P. chilensis which have herma- 
phrodite flowers. Doell also places P. lanuginosa in his herma- 
phrodite section, whilst Emile Desvaux describes it as dicecious, 
as I have generally found it. The stamens, however, are very 
deciduous, and the ovary at the time the stamens are still enclosed 
very minute; and it requires careful observation to ascertain the 
real absence of the one or the other. It is probable that many 
species hitherto supposed to be perfectly hermaphrodite are more 
or less polygamous. P. lanuginosa shows, moreover, an approach 
to Festuca in the fine though short points to the flowering glumes, 
and in the adherence of the grain to the palea. Poidium, Nees, 
a Brazilian species, was separated by Nees from Poa on account 
of a reduction in the number of flowers to one or two, which Doell 
finds to be by no means constant. 
63. CotropiuM, Trin., about ten species, from the Levant and 
Russian Asia, might perhaps be regarded as a section of Poa. 
It differs in very little besides the small spikelets containing only 
one or two flowers, thus connecting Poa with the Agrostez. 
The arctic plant, published by R. Brown as a doubtful Colpodium, 
now forms Grisebach’s genus Arctagrostis, included above under 
Agroste:. 
64. GRAPHEPHORUM, Desv., including Scolochloa, Link (.Flu- 
minia, Fries), and Dupontia, Br., contains seven North-American, 
North-European, or North-Asiatic species, very well worked up 
and distributed into four sections by Asa Gray. They are all 
very near Glyceria, differing chiefly in the hairs surrounding the 
flowering glumes, which induced several botanists to refer the 
genus to Arundine&, though very different in habit and in the 
shape and venation of the glumes. The hairs of the spikelets 
are, moreover, very variable, shorter than in true Arundines, very 
short in the section Aretophila, and not entirely absent in one or 
two species of Glyceria. 
LINN. JOURN.— BOTANY, VOL, XIX. L 
