va 
Part 2, 1913] DICRANACEAE 153 
Type Locaity: Chimborazo, Ecuador. 
DISTRIBUTION: Forests of Barba, Costa Rica; also in northern South America. 
ILLUSTRATION: Hook. Musci Exot. pl. 139. 
4. Dicranodontium costaricense (C. Miill.) R. S. Williams. 
Leptotrichum costaricense C. Mill. Bot. Zeit. 16: 161. 1858. 
Atractylocarpus mexicanus Mitt. Jour. Linn. Soc. 12:71. 1869. 
Leptotrichum ited dea maaae ol Besch. Mém. Soc. Sci. Nat. Cherbourg 16: 174. 1872. 
i Besch: Wénr-See-Sei--Nat- : = 
Dicranum Pittieri Ren. & Card. Bull. Soc. Bot. Belg. 31!: 146. 1893. 
Ditrichum leptocarpum Hampe; Paris, Index Bryol. 394. 1895. 
Cy aie Pittievi Broth. in E. & P. Nat. PA. 15: 337. 1901. “e 
Hes ia leplocorpa cary BEY: Kr ae 1911, 
fe male flowers on Axe short branches a little below the archegonium, often 
3 or 4 together, the inner perigonial leaves short, ovate, narrowly, often faintly costate, enclosing 
6-8 antheridia about 0.25 mm. long, with paraphyses slightly longer: plants in broad yellowish 
to dark-green mats, with stems 1-2 cm. high bearing more or less falcate-secund leaves 5-7 
mm. long: stem-leaves lanceolate-setaceous, subtubulose, serrulate on the margins and back 
nearly one half down, the leaf-blade vanishing about one half up; costa one half the width of 
the lower part of the leaf, in cross-section near the base showing, on the dorsal side, a rather 
narrow stereid-band interrupted by the large outer cells, on the ventral side often only 3 or 4 
cells above the guide-cells but becoming more numerous up near the middle of the leaf where 
a narrow band of stereid-cells may be developed below the outer cells; alar cells hyaline, 
fugacious, not forming auricles, the cells of the lower part of the blade rectangular, with thin 
not pitted walls, those toward the costa 12-16 » wide and 30-60 yu long, smaller and narrower 
toward the margin, not forming a distinct border; inner perichaetial leaves about the length 
of the outer, from a convolute base extending about one third up, rather gradually narrowed 
to the rough point: seta straight or somewhat flexuous, 8-15 mm. long: capsule cylindric, 
erect, smooth, when dry without stomata, 2.5-3.5 mm. long; annulus large, compound; peris- 
tome-teeth slender, about 30 1 wide at the base and 325 u long or more, separate to below the 
‘mouth, divided almost to the base into terete forks, the articulations often indistinct, papillose 
or the outer plates near the base more or less vertically striate; lid with a rostrate beak one 
half to two thirds the length of the capsule: calyptra often reaching to the base of the capsule, 
split on one side from above the middle to the base or only part way down as in D. alpina: 
spores smooth, about 12 » in diameter. 
TYPE LocALIty: Las Nubes, Costa Rica. 
DistRIBUTION: Mexico, Costa Rica, and Guatemala. 
5. Dicranodontium flagellaceum (C. Miill.) R. S. Williams. 
Dicranum flagellaceum C. Mill. Syn. 2: 597. 1851. 
Campylopus flagellaceus Mitt. Jour. Linn. Soc. 12:77. 1869. 
Leptotrichum Pinetorum C. Mill. Linnaea 38: 627. 1874. 
Appearing dioicous, or autoicous with male flowers on slender branches distant from 
the perichaetium, rarely on short branches close to the perichaetium: plants in broad mats 
with somewhat tomentose stems 1-2 cm. high, often bearing flagellate blackish-jointed branches 
clothed with rather short, stowt-pointed leaves: stem-leaves more or less falcate-secund or 
erect-flexuous, lanceolate-setaceous, subtubulose, mostly 4-5 mm. long, the point serrulate 
on the back and margins about one half down; costa nearly one half excurrent, toward the 
base about one third the width of the leaf, in cross-section near the middle of the leaf showing a 
narrow band of stereid-cells on the dorsal side, interrupted by large outer cells, on the ventral 
side a more or less evident stereid-band with or without differentiated outer cells; alar cells 
reddish or hyaline, more or less inflated and auriculate, the cells of the lower part of the blade 
pale, thin-walled, rectangular, mostly 8-12 wide and 40-50 u long toward the costa, toward 
the margin narrower, not forming a distinct border; inner perichaetial leaves about the length 
of the outer, convolute nearly one half up, rather gradually narrowed to a rough point: seta 
mostly 10-15 mm. long, straight or more or less curved or flexuous, especially when moist: 
capsule oblong to cylindric, about 2 mm. long; annulus large; peristome-teeth narrow, at the 
base about 26 » wide, the outer plates vertically striate below, papillose above; lid with a 
