Parr 2, 1913] DICRANACEAE 151 
the teeth at the base in proportion, to their length and in the amount of vertical or oblique striation on 
the outer face. The inflorescence is not at all uniform, often, in the same species. It is as constant 
and as nearly alike in the European Metzleria alpina and Airactylocarpus mexicanus, probably, as 
in any of those under consideration; these two also have calyptras and peristomes very similar but 
the first has the annulus wanting, the second a finely developed annulus. ‘The striation of peristome 
is the greatest in Dicranodontium longirostre and the least in A. mexicanus, being intermediate between 
these two in M. alpina. Dicranodontium longisetum has the most variable striation. Specimens 
from Peru (Spruce 62) and from Bolivia (Williams 1755), scarcely show any striation on some teeth 
or they may be nore striate above than below on the outer face; on the whole the teeth are very 
similar to those of Dicranodontium asperulum; D. longisetum also has the inflorescence more variable 
than has been found elsewhere. It appears at times distinctly dioicous, or the male flowers may be 
at the termination of elongate branches arising from the lower part of the stem, or rarely several 
flowers are found on very short stalks a little below the perichaetium, as in M. alpina. ‘The seta 
varies greatly amongst individuals of the same species in the amount of curvature. 
Annulus none; capsule mostly short-oblong, up to 3 times as long as broad. 
Peristome-teeth 40 wide at the base or less, vertically striate; capsule smooth 
when dry. 
Leaves serrulate one third to one half down or sometimes nearly smooth. 1. D. denudatum. 
Leaves sharply serrulate on the border to below the ovate part of the leaf 
_ or almost to the alar cells. 
Peristome-teeth 60-70 wide at the base, obliquely striate; capsule furrowed 
N 
. D, asperulum, 
when dry. 3. D, longisetum, 
aaa oe capsule more or less cylindric, up to 4 or 5 times as long as 
road. 
Male flowers mostly clustered on short stalks a little below the perichaetium; 
alar cells not auriculate; flagellate branches wanting. 4, D. costaricense, 
Male flowers mostly on elongate branches from the lower part of the stem, 
or thé plants dioicous; alar cells more or less auriculate; plants often with 
rather large, blackish-jointed flagella. 5. D. flagellaceum. 
1. Dicranodontium denudatum (Brid.) E. G. Britton. 
Dicranum denudatum Brid. Musc. Recent. Suppl. 1: 184. 1806. 
Didymodon longirostris Starke; Weber & Mohr, Bot. Tasch. 155. 1807. 
Dicranodontium longirostre Schimp.; B.S.G. Bryol. Eur. (41:) Dicranod. 2. 1847. 
Dicranodontium virginicum E. G. Britton; Millsp. Bull. W. Va. Exp. Sta. 2: 488. 1892. 
Dicranodontium Millspaughi EK. G. Britton; Millsp. Bull. W. Va. Exp. Sta. 2: 488. 1892. 
Dioicous: male flowers solitary, terminal, with numerous antheridia and somewhat 
longer paraphyses, the inner perigonial leaves from a broad, rotundate base abruptly narrowed 
to a setaceous point: fertile plants in compact tufts, with stems 4-8 cm. high bearing more or 
less falcate-secund leaves often readily deciduous: stem-leaves rather uniform, closely placed, 
mostly 5-7 mm. long, from an ovate-lanceolate base rather gradually narrowed to a setaceous, 
subtubulose point 4-5 times as long as the ovate part, the margins and costa on the back 
sserrulate one third to one half down or sometimes nearly smooth; costa one third the width of 
the leaf-base, excurrent, in cross-section showing in the lower part of the leaf on the dorsal 
‘side a stereid-band interrupted by large outer cells, on the ventral side often only a single 
tow of otiter cells, sometimes scarcely evident or higher up the leaf a narrow stereid-band 
‘between the outer cells and guide-cells; alar cells hyaline or reddish, more or less auriculate, 
reaching to the costa; cells in the lower part of the blade oblong to rectangular, with thin not 
pitted or slightly pitted walls, toward the costa 12-16 4 wide and 40-60» long, gradually 
narrower toward the margin but scarcely forming a distinct border; inner perichaetial leaves 
rather longer than the outer, convolute about one third up, rather gradually narrowed to a 
rough point: seta about 1 cm. long, mostly erect-sinuous when dry, sometimes cygneous or 
geniculate either wet or dry: capsule oblong, smooth, about 1.5 mm. long, without annulus or 
stomata, the lid with a rostrate beak scarcely shorter than the capsule; peristome-teeth 
‘separate to below the mouth, at the base about 40 u wide, divided into two forks three fourths 
down or more or sometimes only perforate below, the articulations rather distant and slightly 
prominent on the inner face, vertically striate on the outer face to near the apex or the points 
papillose: calyptra entire at the base, extending to below the middle or to near the base of the 
capsule: spores 10-15 » in diameter. 
Type LocaLity: Thuringia, Germany. ; . 
DistRIBUTION: New England to Florida, and westward to Wisconsin; Orca, Alaska; Oaxaca; also 
throughout Europe. 
—, ILLUSTRATION: B.S.G. Bryol. Eur. pl. 88. ' ; 
/ Exsice.: Sull. & Lesq. Musci Bor. Am. 71; ed. 2. 90; Holz. Musci Acroc. Bor. Am. 102. 
