8 SPHAGNACEiE. 



however, that Cardot (Les Sphaignes d' Europe, 1886, p. 3d) mentions a form 

 received from the United States which had the papillae very slightly developed, 

 and another which, while it had the chlorophyllose cells triangular, as in S. Austini, 

 had the cell walls perfectly smooth. A doubt, however, is permissible whether the 

 latter is properly referable to S. Austini at all. 



The papilke in .S. papillosum are usually not much higher than broad ; in 5 1 . 

 Austini their height is frequently many times their breadth, and they have the 

 appearance of imperfectly developed fibres. 



B. Truncata. 



Cuticular cells of stem without fibres or pores. Stem leaves 

 bordered (very narrowly in S. molle) with narrow cells. Branches 

 straight, closely set. Branch leaves more or less oblong, at apex 

 very truncate and strongly toothed ; the margin usually involute 

 for almost the whole length. Monoicous. 



3. Sphagnum rigidum Schp. (S. compactum var. rigidum 

 Nees) (Tab. VI. D). 



Densely tufted, rigid ; the divergent branches of equal 

 length, short, stiff, obtuse, closely set. Plants of a greyish green 

 or brownish colour. Height 4-9 inches. Stems dark brown. 

 Stem leaves very small, inserted obliquely, triangular-Ungulate, 

 rounded at the apex and eroded, bordered with several rows 

 of narrow cells occupying a considerable proportion of the width 

 of the leaf. Leaves of divergent branches ovate-oblong, slightly 

 cucullate in the natural state, but truncate at apex when pressed 

 flat and examined under the microscope, with 5-7 teeth. Hyaline 

 cells wide but rather short, with unequal but somewhat large pores. 

 Chlorophyllose cells central, narrow elliptical in section, enclosed 

 at back and front by the hyaline. Antheridia on the pendent 

 branches, not on special amentula. 



Var. /?. compactum Schp. (S. compactum De Cand.). Short, 

 very compact, with short, thick branches ; usually tinged with 

 brown or red ; the branch leaves somewhat shorter and rounded 

 at apex. 



Var. y. squarrosum Russ. Looser. Branches usually more 

 distant ; branch leaves more or less squarrose. 



Hab. Heaths and moorlands. Rare. The var. 0. in drier spots, and much 

 more frequent than the type. 



S. rigidum is hardly likely to be taken for any other species except the var 

 congestum of S. cymbifolium and perhaps the var. tenerum of .9. molle From the 

 former it will at once be distinguished upon examination of the stem leaves which 

 in that species are larger, and want the border of narrow cells. The cucullate apex 

 of the branch leaves is also very distinct from that in the present plant, when viewed 

 under the microscope. From S. molle var. tenerum the form and size of the stem 

 leaves will best separate it, these in our plant being small, with the apex rounded and 

 eroded, in that larger, longer, with a narrowed and toothed apex. 



