68 THE SPHAGNACE OR PEAT-MOSSES OF 
The typical state of Sph. acutifolium is that termed robustum by 
Blandow and Nees and Hornschuch, in which the stems are stout 
and often tall, the branches rather short, thick, and glossy, with 
leaves more or less tinted with red. So much, however, does the 
plant vary in size, colour, and density, and in the form of both the 
stem leaves and branch leaves, that an endless series of forms 
result, the transitions between which are so gradual that it becomes 
difficult to keep the varieties within definite bounds. Schliephacke 
pointed out an important character in the structure of the branch 
leaves, viz. that the divergent branches bear up to the middle, 
leaves whose lower wider cells have single large pores, these cells 
becoming towards the point very small, closely and equally small- 
pored ; but as the leaves rise higher on the branches, they gradually 
pass to a lanceolate or lanceolate-subulate form, and the areolation 
then becomes uniform throughout the leaf, wider, laxer, and pro- 
vided with equal large pores. 
The apex of the stem leaves in the robust form is often some- 
what truncate and slightly fringed, and thus may be easily mistaken 
for Sph. strictum, as was the case in my Exsiccata, under n. 42 6 
(var. subfimbriatum) ; but Sph. acutifolium may be known from 
that species by its red amentula, and softer, laxer branch leaves ; 
in other forms the point is obtusely rounded, with small imperfect 
teeth, or again the teeth may be distinct and well defined. 
The stem leaves also vary considerably in form and size; occa- 
sionally we find them very long and ligulate-lanceolate in outline, 
or they may pass to the opposite extreme and be short and broadly 
ovate, but unfortunately these differences are not always asso- 
ciated with the same conditions of habit and colour, and thus a 
sharply defined limit to the numerous varieties of this species 
appears to be impossible. 
Var. B. deflexum, ScuIMP. 
Plants densely tufted, short, with closely placed fascicles. 
Branches long, flagelliform, all deflexed, their leaves closely imbri- 
cated, longer and narrower, pale green and red. Stem leaves 
ovate, pointed, mostly fibrillose. Branch leaves lanceolate, 
acuminate. 
Synon.—Sph. acutifolium var. 8. deflexum, Scuimp. Torfm. p. 57, t. xii. B; 
Synops. p. 673, et ed. 2, p. 826. Russow, Beitr. p. 39 (including also his ar 
laxum). Mu.pk, Bry. Siles. p. 381. Kuinoor. in Schr. der K. Phys. Cek. Gesel. 
zu Konigs. 1872, p. 3. Brairuw. Sphag. Brit. Exsic. n. 32. 
