1919] Long,— Eragrostis peregrina 139 
that, while E. Purshii has been separated from the group with some 
satisfaction, E. peregrina has been almost comprehended in E. pilosa. 
And, truth to tell, its relationship, on a majority of points, does lie 
more nearly with E. pilosa, but in the possession of several constant 
and unique charaéters it amply proves itself specifically distinct from 
both its allies. l 
The characters of E. peregrina may be briefly summarized. The 
most distinctive, separating the plant from both Æ. pilosa and E. 
Purshii, would appear to be: absence of auricular hairs on the upper 
sheaths; panicle densely flowered, bearing a great number of spikelets; 
spikelets ovate or ovate-oblong; pedicels of the spikelets very short. 
Of scarcely less value are those characters which are constant for £. 
peregrina but shared by one or the other of its allies — or both, in the 
single case of absence of hairs in the axils of the panicle branches. 
Among these may be noted: base of the panicle consisting of a single 
branch; absence of hairs in the axils of the panicle-branches; branches 
of the panicle spikelet-bearing to near the base; spikelets about 1.5 
mm. wide; empty glumes with smooth keels, the lower one about 
0.5 mm. long; florets small, usually under 1.5 mm. in length; lateral 
nerves of the flowering glumes inconspicuous; paleas deciduous. 
Similarly, the most salient characters separating Æ. pilosa from its 
two allies seem to be: panicle-branches branched from the one-third 
to the one-half point upward; spikelets tending to be linear, about 
1.0 mm. wide. Characters constant for the species but shared by FE. 
peregrina or E. Purshii: auricles of the sheaths bearing long hairs; 
base of the panicle a pair or a whorl of branches; panicle 
sparsely flowered; pedicels of the spikelets long; empty glumes with 
smooth keels, the lower one about 0.5 mm. long; florets small, usually 
under 1.5 mm. in length; lateral nerves of the flowering glumes in- 
conspicuous. 
For E. Purshii the two categories of characters may be noted in 
like manner. First: spikelets ovate-lanceolate; empty glumes with 
scabrous keels, the lower one about 1.0 mm. long; florets larger, 
usually over 1.5 mm. in length; lateral nerves of the flowering glumes 
conspicuous; paleas persistent. Second: auricles of the sheaths 
bearing long hairs; branches of the panicle spikelet-bearing to near 
the base; panicle sparsely flowered; pedicels of the spikelets long; 
spikelets about 1.5 mm. wide. 
It is not to be thought that in the distinguishing of E. pilosa, E. 
