DIDYMODON. 



67 



D. rigidulum ; leaves closely imbricated on all sides, lanceo- 

 late, much acuminated, carinated, with the rigid nerve run- 

 ning beyond the point ; capsule oblongo-ovate, erect ; lid 

 rostrate. (TAB. XX.) 



D. rigidulum. -He Aw. St. Cr. v. 3. t. 4. Trichostomum rigidulum. 

 Turn. Muse. Hib. p. 34. Engl. Bot. t. 21 78. 



HAB. Walls and rocks. Not uncommon in Ireland. 



" Habitus omnino Tortulce " Mr. Turner has well observed 

 of this plant; indeed so nearly does it approach lo^iortula 

 fallax that it will require an experienced eye to distinguish 

 it without having recourse to the peristome. The nerve of 

 the leaf however is different, singularly rigid, of a brown 

 colour (as well as the leaves themselves), and decidedly run- 

 ning out beyond the point of the leaf; thus the stems 

 have a bristly appearance from the stiffness and sharpness 

 of the foliage. Hedwig's figure, we must observe, does not 

 give a correct idea of this plant, which is in reality more 

 different from D. trifarium than his representations would 

 lead us to suppose. We do not think, indeed, that any 

 stress can be laid on the operculum, which varies somewhat 

 in length in each species ; nor can we consent to their being 

 placed in different genera in consequence of the situation 

 of the supposed male flowers. 



6. D. trifar'mm\ leaves rather distant, somewhat trifarious, lan- 

 ceolate, rather obtuse, carinated, with the nerve scarcely 

 reaching to the point; capsule oblongo-ovate, erect; lid 

 rostrate. (TAB, XX ) 



D. trifarium. Swartz Muse. Suec. Swartzia trifaria. Hedw. St. Cr. 

 v. 2. t. 28. Cynontodium trifarium. Hedw. Sp. Muse. p. 57- Tricho- 

 stomum trifarium. Engl Bot. f.1707. Tr.linoides. Engl Bot. t. 2295. 

 (not of Dicks.) 



HAB. On moist banks. 



Although very closely allied to the preceding species, this 

 may be known by the shorter, more patent, far less rigid, mere 

 distantly placed, and somewhat trifarious leaves. In size it 

 varies considerably, and is often much branched with inno- 

 vations. Our larger plant is the Trichostomum linoides of 

 Engl. Bot. ; and this is of a much paler colour, as well as 

 larger size, than our smallest figures, taken from specimens 

 gathered by our friend Mr. t)rummond, near Cork. 



D. capillacenm ; stems elongated ; leaves nearly distichous, 

 subulate-setaceous; capsule erect, ovato-cylindraceous ; lid 

 conical. (TAB. XX.) 



D. capillaceum. Schrader Spic. Swartz. Mohr. Swartzia'capiU 

 F 2 



