THE BRYOLOGIST 
Vol. XVIII January, 1915 No. 1 
NOTES ON NORTH AMERICAN SPHAGNUM. VI 
A. LeRoy Andrews 
The Group Cuspidata Lindberg 
The group-name Cuspidata was first used by Lindberg 1 , though in an en- 
tirely unnatural sense. It was more naturally defined by Schliephacke 2 and 
has with the segregation of additional species and the fusion of Schliephacke’s 
Mollusca (consisting of a single species) maintained itself to the present. The 
only changes I would make consist in the addition of the Subsecunda which are 
clearly derivative and not sharply separated and also of Sericea and Mucronata 
(the last not American). A character of the group based upon the resorption 
of membrane in stem-leaves and perichaetial leaves has already been noted. 
The one more commonly used is based upon the chlorophyll cells of the branch- 
leaves, which have normally a broader or exclusive exposure on the outer surface 
of the leaf, the opposite being the case in Acutifolia. This feature is not, how- 
ever, of absolute diagnostic value, as we shall see. The cortical cells of the stem 
are as a rule less clearly set off than in other groups and the pores of the leaf- 
cells commonly reduced to something like a minimum, though certain species 
have evolved a more extensive pore-system, the pores being then frequently 
distinctive in number, size, shape and position, so that they have played a con- 
siderable role in the segregation of .species. The stem-leaves average small 
and have a more or less distinctive appearance characteristic of the group. The 
branch-leaves vary much in size in the same species; they are often somewhat 
falcate-subsecund, in some cases undulate and with recurved tips; the pigmen- 
tation, if present, is always brown. With the exception of one species standing 
at the head of the group they are all dioicous, though they may occasionally be 
found fruiting, even abundantly. The group is characteristically boreal, but 
has in some of its forms achieved a more general, even cosmopolitan distribution 
and evidently through these developed a few distinctive non-boreal forms. 
13. Sphagnum Lindbergii Schimper, 1858. Schimper’s good description and 
plate of this species doubtless account in some degree for the fact that it presents 
no questions of priority or synonymy. It is, moreover, a quite distinct form 
and occupies an isolated position in its group, as did S. Angstromii in the pre- 
ceding one. It is immediately distinguishable from all other Cuspidata by the 
remarkably lacerate, fairly large stem-leaves, while it can be separated without 
difficulty from species with lacerate stem-leaves belonging to other groups by 
1 Torfmosso/nas byggnad in Ofvers. kgl. Vet. Akad. Forhandl. Stockholm, XIX, I34f. 1862. 
2 Beitrage zur Kenntniss der Sphagna 413. 1865. 
The November number of The Bryologist was published November 24, 1914. 
