WILLIAMS: THE GENUS DESMATODON 209 
Median leaf-cells and spores 8—10 yu, or less, in diam- 
eter. 
Leaf-cells highly mamillose on the upper surface, 
mostly flat on under side, the lea 
slightly serrulate toward apex. 
Leaves oblong-lanceolate, acute; costa 
slightly excurrent. 8. D. Garberi. 
Leaves oblong-linear, the apex broadly . 
rounded or broadly acute; costa vanishing 
2-3 cells below the leaf-apex. 9. D. Sprengelii. 
Leaf-cells mamillose on both sides; margins of 
the leaf crenulate half way down or more. 10. D. stomatodontus. 
Capsule nodding, more or less curved; leaf-margins thickened. 
Cells of lid scarcely elongate, in erect rows. 1. D. cernuus. 
Cells of lid a little above the base elongate in oblique rows. 12. D. Laurert. 
1. DESMATODON LATIFOLIUS (Hedw.) Brid. Musc. Recent. 
Suppl. 4: 86. 1819 
Dicranum latifolium Hedw. Descr..1: 89. 1789. 
Barbula latifolia Kindb. Eur. & N. Am. Bryin. 2: 252. 1897. 
’  Autoicous, the male flower on a short stalk a little below the 
perichaetium with numerous club-shaped paraphyses surrounded 
by one or more broadly pointed, scarcely longer leaves: fertile 
plants in rather soft, green or brownish green tufts, reddish tomen- 
tose within; stems with central strand, erect, often branching, 
from a few mm. to 2 cm. high; upper stem-leaves more or less 
ovate or obovate to somewhat spatulate, the blade usually 2.5-3 
mm. long and 1 mm. wide, mostly broadly acute, with costa nearly 
percurrent or excurrent into a terete, not quite smooth hair-point 
or in var. muticus the hair-point lacking), the lower leaves 
smaller with costa vanishing below the apex; leaf-margins papil- 
lose, otherwise entire and more or less revolute on one or both 
sides; costa in cross-section showing mostly two large guide-cells, 
three or four cells nearly as large on ventral side, and on dorsal 
side a more or less distinct stereid band with two to four large 
outer cells; cells of upper part of leaf mostly square to short-rec- 
tangular, obscure with numerous round to oblong and c shaped 
papillae; perichaetial leaves scarcely differentiated; seta erect, 
twisted when dry, 1-1.5 cm. long; capsule erect, oblong to cylin- 
dric, 1-2 mm. long; annulus of one to three rows of cells, more or 
less persistent; peristome golden brown, densely papillose, the 
basal membrane extending well above the annulus, with teeth 
mostly split to near the base into two or rarely three slender, erect 
forks, or the forks sometimes united above and slit below; lid 
obliquely beaked, one third to one half the length of the rest of 
