■X. 



—24— 



8 — Lower leaf cells more or less porose; capsules 

 not strumose (except slightly so in D. pal- 

 lidum) 9 



Leaf cells not at all porose; capsules strumose. 12 

 9 — Leaves entire or very faintly denticulate. . . elongatum. 



Leaves serrulate lo 



10 — Leaves strongly falcate-secund; upper leaf 



cells regular fuscescens. 



Leaves little or not at all secund; upper leaf 



cells very irregular 1 1 



II — Costa at least ^ width of leaf at the broadest 



point of the leaf. Plants 3-6 cm. high Miihlenheckii. 

 Costa iV width of leaf; plants 2-3 cm. high, pallidum. 



12 — Leaves falcate-secund ^3 . . 



Leaves spreading schisii. 



13 — Leaves with distinct angular cells; capsule ob- 



long-cylindric Starkei. 



Leaves with few angular cells; capsule short, 



obovate falcatum. 



14 — Costa ending in the serrulate apex; leaves 



curled when dry 15 



Costa excurrent; leaves scarcely altered by 

 drjdng (except D. fulvellum and D. ful- 



vum) 16 



15 — Apex of leaf papillose at back; upper leaf cells 



rectangular monianum. 



Apex of leaf not papillose; upper leaf cells less 

 regular; plants commonly giving off nu- 

 merous axillary erect flagellse bearing mi- 

 nute ecostate leaves flagellare. 



16 — Costa narrow, I to \ width of leaf at base. 17 

 Costa broader, i to i width of leaf. . . .18 



17 — Dioicous; 3-4 cm. or more high Sauteri. 



Autoicous; 0.5-2 cm. high fulvellum. 



18 — Margin and costa of leaves entire; apex usually 



broken viride. 



Margin and costa of leaves serrulate 19 



19 — Costa equalling \ width of leaf at the base, 

 or less; leaves gradually narrowed to apex; 

 all upper surface leaf cells rectangular. . . fulvum. 

 Costa ^ width of base of leaf, or more; 

 leaves abruptly narrowed to a long slen- 

 der point ; all upper leaf cells greatly elon- 

 gated-linear longifolium. 



Look on the summit of your highest accessible hill or moun- 

 tain for the long-leaved Dicranum {D. longifolium). It grows 

 on stone walls and exposed rocks. It is usually sterile, but is 

 easily recognized and distinguished from the fulvous Dicranum 



