Grimmiace^.J ^y [Grimmia. 



Leucodon Ramondi Brid. Mant. 135. 



Dryptodon patens Brid. Bry. un. i, 192 (1826). 



Orthotrichum ? ciirvatum Brid. Bry. un. i, 791. 



Rhacomitrium patens Hueeen. Muse. germ. 198 (1833). Schimp. Synops. 226 (i860), 

 2 ed. 272. Zett. Rev. grimm. sc. 106 (1861). Berk. Handb. br. ra. 236 (1863). 

 MiLDE Bry. siles. 156 (i86g). Hobk. Syn. br. m. 86 (1873). Chalub. Grimm. Tatr. 

 84, t. 12 (1882). HusN. Muse. gall. 138, t. 39 (1887). Lesq. James Moss. N. Amer. 

 148 (1884). 



Grimmia arcuata De Not, in Mem. ace. Torin. xxxviii, 250 (1836), Syllab. 252 (1838). 



GWmmm^a^cHS Br. ScH. Bry. eur. fasc. 25 — 28, p. 18, t. 10 (1845). Rabenh. Deutsch. 

 kr. fl. ii, S. 3, p. 163 (1848). C. Muell. Synops. i, 797 (1849). WiLs. Bry. br. 158, t. 

 19 (i**S5)- De Not. Epil. bri. ital. 692 (i86g). Linde. in Aet, soc. se. fenn. x, 556 

 {1875). JuRATZ. Laubm. oester.-ung. 164 (1882). Boulay Muse. Fr. 375 (1884). 



Dioicous ; in tall flat fragile olivaceous or fuscous green tufts, 

 blackish and nearly naked at base, x\ — 4 in. high, repeatedly 

 dichotomous, with curved branches. Leaves densely crowded, when 

 dry suberect, when moist suddenly recurved, then patent and curved 

 upward, rarely subsecund, elongate lanceolate-acuminate, muticous, 

 carinate-concave below, with the margin revolute up to middle, apex 

 generally subserrate, narrowly carinate, the margin with two rows of 

 cells bistratose ; nerve vanishing in the apex, bilamellate at back, the 

 lamellse bistratose; cells very minute, rounded, the basal angular and 

 yellowish, those next the nerve linear, with several rows next the 

 margin quadrate. Perich. bracts shorter, lanceolate. Caps, bent 

 down on a short yellow cygneous pedicel, elevated a little above 

 perichaetium, oval, smooth, pale fuscous with a red mouth, 8-sulcate 

 when old ; calyptra short, smooth, many-lobed ; lid red, conico-subulate, 

 straight, annulus 2-seriate, broad, revoluble ; teeth on an orange basal 

 membrane, divided into two subulate papillose legs cohering here and 

 there, purple, patent-incurved when dry. Male plant more slender and 

 simpler, infl. terminal, bracts convolute, ovate, shortly acuminate. 



Hab. — Moist quartzose rocks in mountains. Fr. 4 — 5. 



Frequent in Scotland. Slemish mtn., Antrim, and Powerscourt, Connemara (Moore). 

 Galtee-more and Gougaunbarra, Cork (Carroll). Brown Willy, Bodmin (H. N. Dixon 

 1886) ! ! Seandale Glen, Windermere (C. Barton 1888) ! ! Sheepstor (Brent). 



The wings vanish towards the apex and base of the nerve, but their 

 presence is quite sufficient to distinguish this species from G. aquatica, obtusa, 

 elliptica or fascicularis, which have all muticous leaves, while G . Hartmani, elatiov 

 and decipiens, which also more or less resemble it, may be known by the 

 hyaline leaf-points. 



Sect. 4. TRICHOSTOMUM {Hedw.) Taller, dichotomous or irre- 

 gularly branched, with numerous short lateral ramuli. Leaf-cells towards 

 base longer, with strongly sinuose-nodulose walls. Caps, smooth, on a 

 straight seta ; teeth elongate, cleft nearly to base into two filiform legs. 



