612 MUSCI. (MOSSES.) 



Acrocaipi ; stems firm from a suberect rhizoma (hence forming more compact 

 tufts), almost woody, triangular, dark purple, shining ; leaves rigid and coria- 

 ceous, linear-lanceolate, below sheathing, above spreading, and mostly occupied 

 by the broad lamclligerous costa. (Name from TroAvs, many, and 0pi, rpt^c's, 

 a Iiair; from the hairy covering of the calyptra.) 



1. P commune, Linn. Stems erect, mostly simple ; leaves spreading 

 or recurved, flat, serrate on the margins and back ; the lamellae somewhat 2-cleft 

 at their margins ; capsule oblong, 4-sided, the angles acute ; operculum shortly 

 rostrate from a convex base. Shady moist places ; common. Plant 6' -12' 

 high. (Tab. 17.) (Eu.) 



2. P. form 6*U ill, Hedw. Differs from the preceding by its longer and 

 slightly curved capsule with obtuse angles, a smaller obconic apophysis tapering 

 into the pedicel, and the conical operculum. Woods, around the base of trees, 

 &c. (Eu.) 



3. P. gricile, Menzies. Usually somewhat smaller than No. 1 or 2; 

 capsule ovate, 4-6-sided, obtuse-angled; operculum long-rostrate; the hairy 

 covering of the calyptra shorter than the capsule ; spores larger ; basal mem- 

 brane of the peristome not emergent. Boggy places, Ipswich, Massachusetts, 

 Oakes. (Eu.) 



4. P. j u ill peri nil m, Hedw. Stem simple or divided; leaves linear- 

 lanceolate, awn-pointed, denticulate on the back, the margins inflexed, entire ; 

 capsule and operculum as in No. 1. Var. STRICTUM. Stems elongated, slen- 

 der; leaves appressed; capsule cubical. Margins of woods, in exposed places, 

 &c. Plant 4' - 7' high ; the variety subalpine. (Eu.) 



5. P. piliferum, Schreb. Stems simple; leaves clustered at the sum- 

 mit, lanceolate, the margins inflexed, entire ; costa excurrent into a long diaph- 

 anous and spinulose awn ; capsule ovate-oblong, 4-sided ; operculum conical, 

 rostrate. Rocky places, in mountainous districts. Plant 2' -4' high. (Eu.) 



TRIBE XIX. 



46. T 01 HI I A, Hedw. (Tab. 17.) 



Calyptra large, cuculliform. Operculum hemispherical, papillate or with a 

 central depression. Capsule oblong, subpyriform, erect-cernuous, broadly an- 

 nulate, long-pedicellate. Peristome double ; the exterior of 1 6 lanceolate ge- 

 niculate-incurved teeth ; the interior, a membrane divided half way into 64 cilia 

 coherent in fours" at their apices. Inflorescence monoecious : male flower gemmi- 

 form, axillary. Partaking more or less of the characters of Mnium, Aulacom- 

 nion, and Polytrichum ; stems caespitose, ascending from a decumbent radicu- 

 lose base, innovating sparingly above ; leaves of a firm and rather rigid texture, 

 sheathing at the base, elongated-lanceolate, spreading, strongly dentate, with a 

 stout and terete percurrent costa ; areolaj rotund above, elongated-hexagonal 

 below. (Named after ,/. C. Timm, a German botanist.) 



1. T. megapolitansi, Hedw. The calyptra is often arrested in its 

 growth, and found attached to the pedicel, having given egress to the capsule by 



