56 DICRANACE^:. 



It is the commonest species of the three, and is usually rendered more con- 

 spicuous by the numerous capsules than by the appearance of the rest of the plant. 

 The species of this genus are not likely to be mistaken for any others except 

 Archidium altermfolium ; the cleistocarpous species of Weisia, perhaps, most nearly 

 resemble them, but are directly recognised by the upper leaves strongly curled when 

 dry, and the minute, papillose areolation of the leaf apex. 



3. Pleuridium alternifolium Rabenh. (Phascum alterni- 

 folium Kaulf.) (.Tab. XII. G.). 



Densely tufted, stems short, simple ; yellowish green ; in 

 damp or shady spots the stems are frequently elongated, as much 

 as i inch high, with long flagelliform innovations, and of a bright 

 green. Leaves ovate-lanceolate and lanceolate, nerve vanishing 

 in apex ; perichsetial bracts very long, silky, straight when dry, 

 rather abruptly narrowed from an oval base to a long setaceous 

 point, the upper part entirely composed of the excurrent nerve, 

 finely and closely denticulate and muricate ; nerve broad and ill- 

 defined below ; cells at base rectangular and rhomboid, above 

 rectangular, smaller than in the last two species. Capsule oval, 

 with a rather longer apiculus. Male flowers gemmiform, 

 numerous, in the axils of the upper leaves, bracts ovate, acumi- 

 nate. 



Hab. Wet places, borders of fields, etc. ; not very common. Fr. spring and 

 summer. 



A less frequent species than the last with us, though it is the most common of 

 the genus on the Continent. The perichsetial bracts are still longer than in the 

 previous species. 



11. DITRIOHUM Tir 



Plants tufted, slender. Leaves in several rows, lanceolate- 

 subulate, smooth ; areolation rectangular, narrow above. Capsule 

 on a long slender seta, erect or slightly inclined, oval, oblong- 

 cylindrical, or cylindrical, annulate. Peristome teeth erect, 16, 

 not confluent below, elongate, cleft to base into two filiform, 

 papillose, articulate divisions, which are sometimes more or less 

 united ; on a short basal membrane. Spores very small, smooth. 



A genus clearly marked off by the peristome taken in con- 

 junction with the subulate leaves. The name Leptotrichum, 

 which has usually been employed, has been shown by Hampe to 

 be untenable, having previously been taken up for a genus of 

 fungi. 



