rnvsciA.] piTTsciEi. 311 



rate, sessile, brownish-black, ccesio-pruinoso or naked, the thalliiie 

 margin entire or crenate ; spores 0,()lG-24 mm. long, 0,008-11 mm. 

 thick. — Cromb. Grevillea, xv. p, 78. — Pannelia sttllaris Hook. Fl. 

 Scot. ii. p. 55 pro parte ; Sm, Eng. Fl. v. p. 201 pro parte. Lichen 

 steJlaris Linn. Sp. PI. (1753) p. 1144: Ach. Prodr. p. 111. Borrera 

 ohscura /3. chhaalha (non Ach.) !Mudd, Man. p. 110. Physcia retro- 

 f/ressn Stirt. Trans. Glasg. Soc. Xat. 1875, p. 85 vix differt. — As 

 observed by Acharius (Meth. p. 200) the synonymy was then (as it 

 still is) for the most part doubtful. It is, however, the plant of 

 Linnceus according to specimens in his herbarium. — Brit, Exs. : 

 Mudd, n. 81. 



Distinguislied from P. pulverulenta and its varieties by the smaller, 

 epriiinose thallus, which does not become greenish when moist, and by 

 the smaller spores. It has been almost always confounded with tiie fol- 

 lowing species, and especially with its var. ^. The apothecia are nume- 

 rous, chiefly central, with the margin often tiexuose. The spermogones 

 are not untVeauent, with spermatia ec|ually cylindrical, 0,004o mm. long, 

 scarcely 0,001 mm. thick. It is a variable plant, presenting the varieties 

 and subspecies to be described. 



Hah. On the trunks and branches of trees by roadsides, and in avenues 

 of lowland and upland tracts. — Distr. Seen only from a very few localities 

 in N. England and the Grampians, Scotland ; no doubt overluoked else- 

 where. — 13. M. : Near Ayton, Cleveland, Yorkshire. Finlarig, Killhi, 

 Perthshire ; Alonaltrie Iluuse, Ballater^ Aberdeenshire. 



Var. /J. leptalea Xyl. Syn. i. (1860) p. 425. — Thallus narrowly 

 laciniate ; lacinias discrete, ap]>resscd, fibrilloso-ciliate at the margins, 

 the cilia whitish or brownish ; otherwise as in the type. — Cromb. 

 Lich. Brit. p. 39 : Lcight. Lich. Fl. p. 151, ed. 3, p. 140. — LicJu-n 

 leptaJeas Ach. Prodr. (^179>>) p. 108. Borrera hispida Mudd, Man. 

 p. 106. Licltenoides hispidum minus et tenerius, scuteUis ni(/ris Dill. 

 Muse. t. 20. f. 46, a, b, d. 



Differs in the narrower, more discrete, and marginally ciliate lacinioe. 

 It must not be confounded, as has sometimes been done, with less forni- 

 cate states of the following subspecies. The apothecia, which are not 

 unfrequent, vary similarly to those of the type. 



Hab. On the trunks of trees, rarely on rocks, in lowland and upland 

 districts. — Didr. Occurs only here and there throughout England, in 

 N. Wales, S.W. and Central .Scotland; rare in Ireland. — B. M. : St. 

 Leonard's Forest, Sussex ; Lymington, Hants ; Brading, Isle of Wight ; 

 Bolt Head, S. Devon ; near Penzance, Cornwall ; Oswestry, Shropshire; 

 Aberduvey, Merionethshire ; Island of Anglesea ; near Gainsford, Dur- 

 ham. Near Ediuburirh ; Appin, Argyleshire ; Ivillin and Blairdi'ummond, 

 Perthshire : Auchterhouse, Forfarshire ; Cults, near Aberdeen. Carri- 

 galoe, Cork Harbour. 



Yar. y. subobscura Xyl. Siillsk. F. et Fl. Fenn. Forh. iv. 

 (1859) p. 239 ; Syn. i. p. 420. — Thallus greyish or greyish-brown, 

 beneath white with scarcely any rhizinoe ; lacinise short, narrow, 

 the marginal cilia blackish or dark ; otherwise as in the preceding 



