38 GRIMMIACEAE 



middle and upper portions of stems must be chosen for examina- 

 tion. The hyaline apex is often confined to the mature upper 

 leaves. 



Key 



I — Leaves, at least the upper, ending in a whitish hyaline hair point .... 2 



Leaves not as above 5 



2 — Capsule longer than the seta, immersed; or if shorter than the seta 



the upper basal leaf cells are sinuose 3 



Capsule shorter than the seta, emergent or exserted; no leaf cells 



sinucse 6 



3 — Upper leaves with long hair points; leaf cells not sinuose; capsule 



oblong ambigua 



Upper leaves with long hair points; leaf cells somewhat sinuose. 



Pennsylvanica 



Upper leaves oft:n with short hair points 4 



4 — Lower leaf cells sinuose, but shorter than in Rhacomitrium . Pennsylvanica 



Lower leaf cells not sinuose (sometimes slightly so in apocarpa) 5 



5— Plants small and slender, in dense cushions, soft dull green; peri- 

 stome teeth strongly cribrose; central strand present in stem, .conferta 

 Plants larger, loosely tufted; central strand lacking; peristome less 



cribrose apocarpa 



6 — Leaf margins erect, of one layer of cells; seta curved Olneyi 



Leaf margins slightly recurved on one side at least, of one layer of 

 cells; seta straight leucophea 



G. apocarpa (L.) Hedw. "Common on rocks in moist ra- 

 vines," Muse. App. 134. Frequent on S. Id. but much of the 

 plant is possibly var. rividaris. Bronx R. near bridge, E. G. B., 

 Bx! No specimens known from L. Id. 



Var. gracilis (Schleich.) W. & M. "Shaded rocks, Pali- 

 sades and Greenwood Mts.," Muse. App. 135; Bloodroot Valley, 

 S. Id., E. G. B., Bx! Autumn-winter. 



G. ambigua Sull. "Rocks on High Tom, Haverstraw, N. 

 Y.," Muse. App. 142. 



G. conferta Funck. "On rocks on the ground, Passaic Falls, 

 N. J.," Muse. App. 138. Varieties on limestone rocks near 

 Sparta and in Southern N. J., Muse. App. 139 & 140. "On 

 trap rocks near Haverstraw, N. Y.," Muse. App. 141. 



G. leucophea Grev. "Exposed rocks, Palisades," Muse. 

 App. 146. Spring. 



