Analytic Keys to the Species of Mosses. 
61 
OLIGOTRICHUM, p. 258. 
Lamina and costa lamellose on both surfaces ... 0. aligerum, 1. 
Costa only lamellose on upper surface .... 0. Lyallii, 2. 
s 
POGONATUM, p. 260. 
I. Plants simple, mostly short, leaves straight when dry. 
[P. alpinum var. simplex will be sought here.] 
Lamellae with marginal cells smooth. 
Leaves entire.P. hracliypliyHum, 2. 
Leaves serrate.P. brevicaule, 1. 
Lamellae with marginal cells papillose. 
Teeth of leaves very long, often reflexed, marginal cells 
of lamellae subquadrate.P. dentatum, 4. 
Teeth moderate, 2 rows of marginal cells of lamellae 
transversely rectangular.P. capillare, 3. 
II. Plants large (4-15 cm.), leaves tivisted when dry. 
Leaves very long (1.5-2 cm.) short sheathing, lamellae 
afbout 60 . .P. Macounii. 1 
Leaves less than 1 cm., short sheathing, lamellae about 
30 (?) 2 , strongly contorted when dry . . . P. contortum, 5. 
Leaves and lamellae as in 5 (?) subcrispate, abruptly 
pointed.P. atroyirens, 6. 
III. Plants usually robust (4-15 cm.), rarely small, often much branched 
above, leaves straight when dry. 
Capsule papillose, marginal cells of lamellae round in sec¬ 
tion .P. urnigerum, 7. 
Capsule smooth, marginal cells of lamellae ovate in section P. alpinum, 8. 
POLYTRICHUM, p. 263. 
Leaves entire, margins inflexed. 
Obtuse at apex.P. sexangulare, 3 Florke. 
1 Kindberg: Polytriehum (Pogonatum) Macounii: Bull. Torr. Bot. Club xvi (1889), 96. 
2 As shown in Sull. Icon. Muse. Suppl., pi. 42, ff. 5, 6. 
3 Kindberg: Bull. Torr. Bot. Club xvi. (1889), 96; Renauld & Cardot: Bot. Qaz., xiv.. 
(1889) 99. 
