24 POLYTRICHUM. 



plane, denticulated, their nerve winged; capsule cylindrical j, 

 curved ; lid subulate. (TAB. X.) 



P. undulatum. Hedw. St. Cr. v. 1. t. 16-17- Turner Muse. Hib. 

 p.9L Engl.Bot. t. 1220. Catharinea Callibryon. Ehrh. Catharinea 

 xmdulata. Web. et Mohr. Moug. et NestL n. 131. Biyum undula- 

 tnm. Linn. Dill Muse. t. 46. f. 18. 



HAB. Common on moist shady banks and in woods. 



Stems from one to two inches high, leaves of a thin and 

 delicate structure, (unlike those of the rest of the genus,) 

 crisped when dry. A very remarkable variety of this plant 

 has been found by Mr. Templeton in the Dargle near Dublin, 

 with fruitstalks scarcely two lines in length, and the back of 

 the leaf furnished with evident denticulations, which latter 

 circumstance is not confined to this variety and has been 

 noticed by Bridel. The winged nerve we do not remember 

 to have been previously noticed, it is a narrow foliaceous 

 appendage running along each side of the nerve. Some- 

 thing of this kind may indeed be observed on the nerves of 

 almost all the Poly trie ha (as may be seen by our figures) ; 

 that is to say, they are furnished in a more or less obvions 

 degree with Iamella3, which in Poly trie hum Icevigatwtn of 

 Wahlenberg are so prominent as almost to resemble the leaves 

 of a book : in the following species, P. hercynicum, they are 

 less apparent, and in most of the larger species give the 

 nerve a striated appearance. 



2. P. hercynicum\ leaves lanceolate, rigid, entire, their sides 



involute; their nerve broad, impressed with furrows; cap- 

 sule oblong, sub-erect; lid conical. (TAB. X.) 



P. hercynicum. Hedw. St. Cr.v. 1. 1. 15. Engl. Bot.t. 1209. Catha- 

 rinea hercynica. EHrh. Mohr. Bryum incurvum. Hurts. 



HAB. On mountains at a considerable elevation. 



Stems short. Leaves as it were intermediate in texture 

 between those of P. ujidulatum and the rest of the Poly- 

 tricha. 



* * Calyptra covered with succulent Jiluments. 

 f Leaves entire ; their margins involute. 



3. P. piliferum ; leaves lanceolato-subulate, their margins in- 



volute, entire, terminating in a pellucid hair-like point; cap- 

 sule ovate, obtusely quadrangular, furnished with an apo- 

 physis ; lid conical. (TAB. X.) 



P. piliferum. Scfireb. Fl. Lips. p. 74. Menzies in Linn. Trans. ' 

 Turn. Muse. Hib. p. 82. Engl. Bot. t. 1199. Moug.et NestL n. 128, 

 jp7/, Muse. t.54.f.3. 



