ANALYTIC KEY 



TO THE 



SPECIES OF MOSSES, 



SPHAGNUM, p. 12. 



I. Cortical cells of stem and branch without spiral fibrils; branch 

 leaves mostly blunt and toothed, rarely acute. 



Branches 7— 13 in a fascicle ... § IV. Polyclada, p. 173. 



Branches 3 — 6 in a fascicle, or fewer. 

 Hyaline cells of stem leaves fibrillose. 

 Cortical cells thin walled. 

 Border of stem leaves much broader at base, chloro- 



phyllose cells exposed on the inner face §1. Acutifolia, p. 171, 

 Border of stem leaves not or slightly broader at the 



base §VI. Subsecunda, p. 173. 



Cortical cells thick walled . . . . §1X1. Cuspidata, p. 172, 

 Hyaline cells of stem leaves without fibrils. 



Chlorophyllose cells of branch leaves exposed on 



inner face §1. Acutifolia, p. 171. 



[S. subsecundum and S. contortum may be sought here.] 



Chlorophyllose cells exposed on both faces, only on outer face, or in- 

 cluded. 

 Cell membranes of stem leaves resorbed. 

 Hyaline cells of branch leaves with few pores on 



the outer surface (4-6) . . §11. Sqnarrosa, p. 172. 



Hyaline cells of branch leaves with numerous 



pores on outer surface (12-16+) . . §V. Rigida, p. 173, 

 Cell membranes of stem leaves not resorbed, cortex 



thick walled .... §111. Cuspidata, p. 172, 



