156 NORTH AMERICAN FLORA [VoLumE 15 
1. Oreoweisia serrulata (Funck) De-Not. Atti. Univ. 
Genova 1: 489. 1869. 
Weisia serrulata Funck; Brid. Bryol. Univ. 1: 804. 1827. 
Oreoweisia obtusata Kindb. Rev. Bryol. 23:18. 1896. 
Cynodontium obtusatum Kindb. Eur. & N. Am. Bryin. 184. 1897. 
Autoicous: male flower on a short stalk below the perichaetium, the perigonial leaves few, 
the inner ovate, bluntly pointed, ecostate, pale-brown to the apex, the outer ones ovate- 
lanceolate, strongly costate, green and mamillose toward the apex, loosely enclosing a few 
antheridia about 0.3 mm. long with filiform paraphyses nearly twice as long: plants in 
compact green or rather dark-green tufts 2-5 cm. high; stems simple or with short branches, 
bearing scattered, mostly papillose (or nearly smooth in the American plant) radicles up 
to the latest innovations: leaves spreading-incurved when dry, mostly erect-spreading on 
all sides when moist, up to 2.5 mm. long, from broadly ovate-lanceolate to linear-lanceolate, 
rather broadly acute to blunt at the apex, crenulate-serrulate on the margins about three 
fourths down, deeply keeled above with flat borders, the borders somewhat recurved below; 
costa stout, mamillose chiefly on the under side, vanishing just below the apex, in cross- 
section near the middle showing mostly 2-4 guide-cells, a single row of rather large cells on the 
upper side, a more or less interrupted stereid-band on the under side with the outer cells 
differentiated; cells of the leaf-blade green, highly mamillose or pointed-mamillos on both 
sides often three fourths down the leaf arid roundish to nearly square, the median ones 6-7 u 
in diameter, those toward the base becoming pale-brown, square to short-rectangular, smooth, 
the alar not differentiated; perichaetial leaves very similar to the longer stem-leaves: seta 
erect, about 5 mm. long: capsule erect, regular, oblong or sometimes slightly curved and nod- 
ding, smooth, up to 1.2 mm. long with usually a rather distinct neck and few stomata; annulus 
none; peristome-teeth golden-brown, separated mostly to below the rim of the capsule, lanceo- 
late, mostly undivided and without a median line, smooth or nearly so, with distinct articula- 
tions; lid obliquely conic or shortly beaked, its height 1-1.5 times the basal diameter: calyptra 
cucullate, reaching well down the capsule, smooth above, entire at the base: spores rough, 
18-20 » in diameter. 
‘TYPE LOCALITY: Switzerland. 
DistRIBUTION: ~New York; New Jersey; Pennsylvania; Minnesota; Port Arthur, Ontario; 
Hector, British Co bia; Alaska (according to Lesquereux & James, the specimens said to be 
fruiting); also in Europe and Siberia. 
ILLUSTRATIONS: B.S.G. Bryol. Eur. pl. 27; Rab. Krypt.-Fl. 4: f. 108. 
Exsice.: Aust. Musci App. 70. 
‘The American plants on the average have rather smaller leaves than the European and the radicles 
are mostly smooth but occasionally papillose. The only fruiting specimens known from America 
seem to be those credited to Alaska, and the description of fruit above given is based entirely on 
European plants. 
19. DICHODONTIUM Schimp. Coroll. Bryol. Eur. 12. 1855. 
Dioicous: plants in rather compact, yellowish to dark-green cushions or sometimes in 
extensive, lax mats; stems with a central strand, three-sided, radiculose below with often 
very slender innovations from just below the apex. Stem-leaves when dry mostly spreading- 
incurved or somewhat crispate from an erect base, when moist widely spreading, from oblong 
or ovate to oblong-lanceolate or somewhat lingulate with a broad, keeled point and rounded or 
broadly acute apex, the margins above flat and serrulate or irregularly serrate; costa stout, not 
quite percurrent, in cross-section near the middle showing a single row of guide-cells with 
stereid-bands above and below and outer cells differentiated; upper leaf-cells mostly not 
elongate, quadratic or roundish, more or less papillose on both sides, often obscure, the lower 
ones mostly paler, not hyaline, smooth just above the base, the alar not differentiated. Seta 
elongate, erect: capsule erect or nodding, nearly symmetric or more or less curved, oblong or 
shortly cylindric, the walls of thick texture, smooth, with stomata at the base; annulus wanting; 
peristome dark, attached below the mouth, the teeth lanceolate, united below, more or less 
divided about one half down, minutely papillose and vertically or variously striate on the 
outer face. Calyptra cucullate, entire at the base, more or less rough above. 
Type species, Byrum pellucidum L. 
