1922] ! Inman,—Calamagrostis canadensis 143 
magrostis Langsdorfi as a species simply leads to confusion since the 
gradations or transitions from and to it, through C. canadensis, var. 
robusta, are so many and so close and since in all three plants the 
details of the spikelets are identical. These plants are, therefore, 
treated as variations of one species. 
Callus-hairs about as long as to longer than the lemma. 
Spikelets 2.25-2.75 mm. long: awn usually attached above 
the middle of the lemma: palea and lemma subequal. ..C. Macouniana. 
Spikelets 3-5.5 mm. long. 
Awn attached at or below the middle of the lemma: palea 
L2 the length of the lemma 
Spikelets 3-3.5 mm. long.................. C. canadensis (typical). 
Spikelets 3.5—4.5 mm. long............... C. canadensis, var. robusta. 
Spikelets 4.5-5.5 mm. long............. C. canadensis, var. Langsdorfi. 
Awn attached at the tip of the lemma: palea 24-34 the 
EE ee C. blanda. 
Callus-hairs 14-34 the length of the lemma, mostly few. 
Awn attached near the base of the lemma: callus-hairs 
lí-Véthe length of the lemma. 
Spikelets 3.5—4 mm. long: palea 24-34 the length of the 
oy bs ue ce te er C. perplexa. 
Spikelets 4-5 mm. long: palea and lemma subequal...... C. Porteri. 
Awn attached only slightly below the middle of the lem- 
ma: callus-hairs 14-14 the length of the lemma: spikelets 
3-4 mm long: palea and lemma subequal ................ C. Scribneri. 
CALAMAGROSTIS MaAcOUNIANA Vasey, Contrib. U. S. Nat. Herb. 
ili. 81 (1892). Deyeuxia Macouniana Vasey, Bot. Gaz. x. 297 (1885). 
C. CANADENSIS (Michx.) Nutt Gen. i. 46 (1818). Arundo canaden- 
sis Michx. Fl. Bor.-Am. i. 73 (1803). A. agrostoides Pursh, Fl. Am. 
Sept. i. 86 (1814). 
Var. ROBUSTA Vasey in Wheeler Rep. vi. 285 (1878). Var. acuminata 
Vasey in Rydberg & Shear, U. S. Dept. Agric. Div. Agrost. Bull. 
no. 5: 26 (1897). 
Var. Langsdorfi (Link). n. comb. Arundo Langsdorfi Link, Enum. 
Pl. Hort. Berol. i. 74 (1821). C. Langsdorffii Trin. Gram. Unifi. 225, 
t. 4, fig. 10 (1824). C. scabra Presl, Rel. Haenk. i. 234 (1828). Dey- 
euxia Langsdorfi Kunth, Rev. Gram. i. 77 (1829). C. hirtigluma 
Steud. Syn. Pl. Gram. 188 (1855). C. oregonensis Buckl. Proc. Acad. 
Phil. 1862, p. 92 (1863), in part, acc. to Gray, ibid. 334 (1863). 
C. BLANDA Beal, Grasses N. Am. ii. 349 (1896). C. columbiensis 
Nutt. ex Gray, Proc. Acad. Phil, 1862, p. 334 (1863), incidental 
mention in synonymy. C. pallida Vasey & Scribn. in Vasey, Contrib. 
U. S. Nat. Herb. iii. 79 (1892), not C. Muell, Annal. Bot. Syst. vi. 
986 (1861), where Mueller erroneously ascribes C. pallida to Blytt, 
Norg. Fl. i. 90, Blytt having merely published C. Pseudophragmites, 
var. pallida the description of which Mueller literally translated. 
C. PERPLEXA Scribn. U. S. Div. Agrost. Cire. no. 30: 7 (1901). 
Deyeuxia Porteri Dudley, Cayuga Fl. 125 (1886), not C. Porteri 
