Grimmiace.e. 40 'Grimmia. 



Trlchostomnm cataractarum Hartm. Skand. fl. 3 ed. 283 (1838). 

 Grimmia aquatica C. Muell. Synops. i, 800, excl. syn. (1849.) 



Dioicous ; in lax wide depressed mats, dull or yellow-green above, 



ferruginous below. Stems elongated, more slender, i — 4 in. high, 



ascending, repeatedly dichotomous, less rigid, dense-leaved. Leaves 



when dry laxly incumbent, when moist suddenly recurved, then erecto- 



patent on all sides, or subsecund, from an oval-oblong base, gradually 



lanceolate, obtuse, muticous, quite entire, canaliculate, unequally 



recurved and not incrassate at margin, unistratose ; nerve strong, 



reddish brown, ending in the apex ; cells at base long, very narrow, 



above minute, incrassate, yellow, strongly punctulato-crenulate at 



margin. Perich. bracts sheathing, thin, nerve shorter. Caps, pseu- 



dolateral, on a longish pale brown seta, elongato-elliptic, erect, 



leptodermous, ferruginous, often scarce overtopping the elongated 



innovations ; calyptra 5-lobed, acicular ; lid acicular, straight, red 



I length of caps. ; annulus broad ; teeth rufous, bipartite, the legs free, 



entire or partly cohering, perforated. Male infl. terminal, bracts ovate, 



shortly acuminate. 



Hab. — Dripping rocks and waterfalls. Fr. 3 — 4. 



Cronkley Fell, Teesdale (Nowell 1851) ! ! Bleabeck Scarr and White Force, Teesdale 

 (Baker 1856) ! Snowdon (Wilson) ! ! Beddgelert (Coward 1858) ! Ben Lomond 

 (Dr. Wood 1859) ! Glengariflf (Hunt 1864) ! Bowness (Barnes i86g) ! ! Lochgoil 

 head (Hunt 1866). Taycleave (Holmes). Lough Bray (D. Orr). Brandon and 

 Macgillicuddy's Reeks (Moore). Isle of Man (Holt). Slievedonard (Lett). Brecon 

 Beacon (Boswell 1883). Tyn-y-gros and Crib Goch (Holt 1882). 



In appearance this much resembles G. patens, but apart from the wings 

 on the nerve of that species, the leaves in G. aquatica are obtuse, quite entire, 

 with the basal areolation much more sinuose ; from G. aciciilaris it differs in 

 the slender stems and narrower lane, leaves, and the basal areolation is 

 much coarser. 



32. GRIMMIA OBTTJSA (Sm.) Lindh. 



Dioicous ; short, densely pulvinate. Leaves quite beardless, ovate- 

 oblong, gradually acuminate, obtuse at point, nerve lost far below apex, 

 margin narrowly revolute. Caps, oblong, narrowed at mouth, lid 

 acicular, peristome fugacious, irregular, teeth with 2 unequal legs. 

 (T. LI, E.) 



Syn. — Bryiim hyfnoides alpinnm, operculis obtusis Dill. Hist. muse. 371, p.p. t. 47, f. 30 

 (1741) et Herb. 



Bryiim hypnoides 8. HuDS. Fl. angl. 411 (1762). 



Trichostotnum obtusum Sm. Fl. brit. 1244, excl. syn. Brid. (1804), Comp. fl. brit. 

 2 ed. 171 (1816). 



Dicranum aciculare 8. pumilum Turn. Fl. hib. 67 (1804) ? 



Trichostomum patens W.-Arn. H, in Hook. J. Hot. i, 95 (1834). 



