68 Rhodora [APRIL 
8,000 ft. (Colo.]." This description leaves little doubt as to the mean- 
ing of the name, and, indeed, Scribner and Smith consider it a synonym 
of A. Richardsoni. As the first varietal name Vasey's combination 
is the correct one. The following quotations will throw some light 
on the nature of A. caninum (L.) Beauv. var. unilaterale (Cassidy) 
Vasey, and also upon its relationship. Ramaley' says: “From this 
description [Vasey's] and from an examination of specimens distrib- 
uted by the Department of Agriculture it appears that this plant is 
very near to A. violaceum (Hornem.) Lange, forma caninoides* 
described below; it is probable that through these formae? the two 
species * are related.” Ramaley, having apparently read only Vasey's 
brief description assumes that 4. caninum var. unilaterale differs 
only very slightly from the type. 
Scribner and Smith, under A. caninum (L.) Beauv., write: “ Forms 
of this, with unilateral spikes, have been referred to A. richardsoni, 
which has awns three or four times as long as those of caninum, and 
the flowering glume bidentate below the origin of the awn. Slender 
forms have been referred by collectors to A. tenerum Vasey, and forms 
with short compact spikes and short awns to A. violaceum Vasey.” 
Scribner and Smith * describe Agropyron tenerum Vasey var. longi- 
folium. We have seen no specimens of this, and are therefore unfor- 
tunately unable to discuss it. 
We may now proceed to the taxonomic treatment and diagnoses. 
We desire to call attention to the fact that the measurements in all cases 
represent the usual or average limits, and that measurements may be 
observed which lie above or below them. For example, if the awns 
are said to be 1-3 cm. long, some awns may be found 0.8 or 4 cm. long, 
but this would not apply to more than a small proportion of the awns 
in the given spike. Approximate averages are given whenever possible, 
to show the proportional size of the spikes, which is an important 
character. 
1 Geol. Nat. Hist. Surv. Minn.— Minn. Bot. Studies, Bull. no. 9, 3, 107 (June 9, 1894). 
2 We believe this form to be inseparable from A. caninum. It does not seem best to 
retain names for intermediate forms of this sort, where no sharp line exists, for there is 
no more reason for using one name than several, 
3 A. violaceum (Hornem,) Lange f. caninoides Ramaley and A. violaceum (Hornem.) 
Lang» f. violacescens Ramaley. The latter is Ramaley's name for A. caninum var. 
unilaterale. 
4 Ramaley means here A, caninum and A. violaceum, 
5 Vasey does not mention the awns. 
6 U. S. Dept. Agr. Div. Agrost. Bull. no. 4, 30 (Feb. 6, 1897). 
