SPHAGNUM. 



9 



_ A curious feature of this species is that the perichsetial leaves are, in their areola- 

 tion, much more like those of the branches than the stem leaves, whereas in almost all 

 the other species they resemble the stem leaves in this structure. 



The pores in the hyaline cells of the branch leaves are in this and the follow- 

 ing species occasionally found on the face of the hyaline cells, as well as along their 

 sides adjoining the chlorophyllose cells ; this is not the case with any of our other 

 species except S. acutifolium. 



4. [Sphagnum molle Sull.J (Tab. VI. E.) 



Usually pale or yellowish green, in soft tufts. Height 3-6 

 inches. Stems pale green. Stem leaves large, usually broadly 

 lingulate-spathulate or obovate-spathulate, narrowed to the obtuse 

 apex, which is 3-7 toothed ; bordered with a very few rows of 

 linear cells ; the median cells, in the type, faintly fibrose and 

 porose in the upper part of the leaf only. Leaves of divergent 

 branches ovate-oblong or ovate-acuminate, concave, convolute 

 above; -apex more or less truncate and 5-6 toothed. Hyaline 

 cells with a few large pores. Chlorophyllose cells oval-triangular 

 in section, ventral, but sometimes reaching the dorsal surface. 



Type not found in Britain. 



Var. /3. Mulleri Braithw. (S. Mullen Schp. Syn.). Stem 

 leaves with the cells strongly fibrose and porose almost to the 

 base. 



Var. y. tenerum Braithw. In dense, short, whitish tufts. 

 Branches more closely set, short, with acuminate leaves. 



Hab. The var. /3 by moorland streams, not common. The var. y in drier 

 places. 



The var. Miilleri has by various authors been considered a separate species ; 

 it is very doubtful, on the other hand, whether it is even deserving of a varietal status. 

 The minor points of difference sometimes cited seem to have little or no value. For 

 instance, the stem leaves in the variety are said to be more elongate, but in a speci- 

 men of ^. molle of Schimper's gathering I find them even narrower and more, 

 elongate than in the usual form of the var. Mulleri. And with regard to the main 

 character, the areolation of the cells of the stem leaves, it is to be remarked that 

 even were it a perfectly defined and permanent character, it is hardly one of specific 

 value ; and this, moreover, it is far from being. In specimens gathered on Helvellyn 

 I find the cells strongly fibrose and porose, but only throughout the upper half of the 

 leaf, thus forming a somewhat intermediate link between the two ; while Cardot 

 (Les Sphaignes d' Europe, 1886, p. 44) says that in Belgian specimens from near 

 Antwerp he has frequently found stems bearing leaves in some of which the cells were 

 strongly fibrose while in others the fibres were entirely absent. The strongest point, 

 perhaps, is the distribution, S. molle being frequent in the United States, but 

 apparently very rare in Europe, while the var. Mulleri appears to be less widely 

 known in America, and is certainly the commoner plant in Europe, and in some 

 countries at least, the only form. 



S. molle is sometimes very difficult to distinguish from other species, and espe- 

 cially from S. acutifolium, although the latter is usually a more slender plant ; in 

 these cases it is difficult to name any one character by which they may be definitely 

 separated. The absence of red in our plant is usually enough to determine it, together 



