34 
Basing the leading key characters on the above remarks, the Canadian 
forms of Agropyron may be arranged as follows: 
1. Anthers at most 2 mm. long A. “ caninum " and allies 
1. Anthers 3 mm. long or longer 
2. Creeping rootstocks present; plants forming mats, open 
colonies, or loose clumps 
3. Empty glumes as a rule faintly nerved, long-attenu- 
ate; sterile shoots with corymbiformly arranged 
leaves . . .A. Smithii 
3. Empty glumes as a rule strongly nerved, bluntish 
to acuminate 
4. Sterile shoots with racemiformly arranged leaves 
5. Empty glumes acute or acuminate A. repens 
5. Empty glumes bluntish. A. pungens 
4, Sterile shoots with cor ymbiformly arranged leaves. A. dasystachyum and allies 
2. Creeping rootstocks absent; plants densely tufted; 
sterile shoots with racemiformly arranged leaves A. spicalum 
That this arrangement is more natural than one based on presence or 
absence of pubescence and awn on the lemma seems substantiated by the 
number of chromosomes found in the various groups. According to Peto 
(14, page 441) the number of somatic chromosomes are as follows: 
A. caninum , A. Richardsoni , A. tenerum, 28; A. Smithii, 56; A. repens 
and A. pungens, 42; A. dasystachyum, 28; A. spicatum, 14. 
THE NORTH AMERICAN ALLIES OF AGROPYRON 
CANINUM (L.) BEAUV. 
The most important paper on this subject is that of Pease and Moore, 
Rhodora, 12, pages 61-77, 1910, entitled ct Agropyron Caninum and Its North 
American Allies Pease and Moore deal with this group of Agropyron in 
a rather broad manner and recognize, besides A. caninum (L.) Beauv., 
the following varieties and forms: A. caninum f. pubescens (Scribn. & 
Smith) Pease & Moore, A. caninum f. glaucum Pease & Moore, A. 
caninum var. tenerum (Vasey) Pease & Moore, A. caninum var. tenerum 
f. ciliatum (Scribn. & Sm.) Pease & Moore, A. caninum var. tenerum 
f. Fernaldii Pease & Moore, A. caninum var. latiglume (Scribn. & Sm.) 
Pease & Moore, A. caninum var. Hornemanni (Koch) Pease & Moore, 
A. caninum var. Hornemanni f. pilosifolium Pease & Moore, A. caninum 
var. andinum (Scribn. & Sm.) Pease & Moore, A. caninum var. Gmelini 
(Ledeb.) Pease & Moore, A. caninum var. Gmelini f. Pringlei (Scribn. & 
Sm.) Pease & Moore, A. caninum var. unilaterale (Cassidy) Yasey, A. 
caninum var. unilaterale f. ciliatum (Scribn. & Sm.) Pease & Moore. 
Of the above varieties and forms the var. Gmelini and its f. Pringlei 
deserve a few words of comment. The name Gmelini first appears in 
Ledebour, Flora Altaica, 1829, as a varietal name under Triticum caninum. 
The variety, however, was not described there, but a reference was made by 
Ledebour to tab. 248 of his leones PI. FI. Ross. There, accompanying the 
plate, a description was given by Griesbach, 1831, as follows: 
“ Triticum caninum var. Gmelini Tab. CCXL\ III 
“T. caducei linearis axi continuo, spiculis sub-5-floris, glumis aequalibus concavo- 
laneeolatis 5-nervibus acutis fiosculis praelonge subuliferis dimidio brevioribus, 
radice fibrosa vel subrepente.” 
