TORTULACE^.] 202 [Pottia. 



10. POTTIA ASPERULA Mitten. 



Paroicous ; densely caespitose. Leaves quinquefarious, obovate- 

 spathulate, obscure, papillose, nerve excurrent ; caps, oval, lid conic, 

 rostellate, cal. papillose. (T. XXIX, D.) 



SYN. Pottia aspcrula MITT. Journ. Bot. 1871, p. 4. BRAITHW. Journ. Bot. 1871, p. 290. 

 HOBK. Syn. br. m. 56 (1873.) 



Paroicous ; densely caespitose, short, pale yellowish-green. Leaves 

 quinquefarious, obovate-spathulate, acute, not acuminate, nerve excur- 

 rent in a longish point, margin slightly recurved ; upper cells quadrato- 

 hexag. rather- obscure, each with several minute conical papillae, lower 

 hexagono-rectang. smooth, pellucid. Seta rather short, reddish yellow, 

 caps, oval or turbinate when empty, widest about the middle, reddish 

 brown ; cal. with scattered obtuse papillae on the upper half; lid paler, 

 conic with a short oblique obtuse beak. 

 HAB. Banks and crevices of rocks near the sea ; rare. Fr. i 3. 



Henfield, Sussex (Mitten) ! ! Jersey (Piquet). Howth, Dublin (Moore 1856). Penlee 

 point, Penzance and Perran cliff (Curnow 1871) ! ! 



This much resembles P. truncatula, but has leaves more obscure and 

 papillose, as is also the calyptra. P. viridifolia and crinita are distinguished 

 by octofarious leaves and a smooth cal. though in other respects coming very 

 near to it. 



ii. POTTIA VIRIDIFOLIA Mitten. 



Paroicous ; densely caespitose. Leaves octofarious, obovate- 

 spathulate, papillose, nerve excurrent ; caps, oblong, lid rostellate, cal. 

 smooth. (T. XXIX, E.) 



SYN. Pottia pallida (non LINDB.) BRAITHW. Journ. Bot. 1870, p. 255. 



Pottia viridifolia MITT. Journ. Bot. 1871, p. 5. BRAITHW. Journ. Bot. 1871, p. 290. PI. 

 119, f. 4. HOBK. byn. br. m. 57 (1873). 



Paroicous ; densely caespitose, bright yellow green. Leaves 

 octofarious, forming a rosette-like coma, obovate-spathulate, erecto. 

 patent, obtuse or slightly acute, margin recurved at the middle, nerve 

 excurrent in a short point ; upper cells hexagonal, obscure with 

 chlorophyl, papillose, lower oblong, hyaline, smooth. Caps, on a short 

 yellow seta, oblong, narrower than in P. asperula, rufous brown ; cal. 

 smooth, lid rostrate. 

 HAB. Earthy ledges of rocks by the sea ; not common. Fr. i 3. 



By an old quarry near St. John's, Plymouth (Holmes 1870) ! ! Slate rocks at Pentire and 

 Withiel (Tellam 1871) ! ! Boscawen cliff and Tregyptian cliff, Penzance (Curnow 1872) ! ! 

 Basaltic rocks at Blackhead, Belfast (Stewart 1884) ! ! 



The deep green colour and firm texture of this plant are remarkable, 

 and the leaves are appressed and twisted when dry. 



