PAKMKLIA.] PARMEI.TKT. 239 



8. P. tiliacea Ach. Meth. (1803) p. 215. Thallus orbicular, 

 membranaceous, appressed, smoothish or partly rugulose, laciniato- 

 lobed, pale greyish-glaucous, subpruinose ; beneath brownish black 

 and black-fibrillose ; lobes short, subimbricate, rounded and sinuato- 

 crcnate at the margins ( K+J' eilowi8h , CaCl~ red ). Apothecia mode- 

 rate, crowded, concave or nearly plane, badio-reddish, the margin 

 subentire; spores 0,007-11 mm. long, 0,005-7 mm. thick. Gray, 

 JS T at. Arr. i. p. 438 ; Sm. Eng. Fl. v. p. 204 pro parte ; Mudd, Man. 

 p. 93, t. ii. f. 28 ; Cromb. Lich. Brit. p. 33 pro parte ; Leight. Lich. 

 Fl. p. 131 pro parte, ed. 3, p. 121 pro parte. Lichen tiliaceus Hoffm. 

 Enum. (1784) p. 26 pro parte, t. xvi. f. 2 ; Dicks. Crypt, fasc. iii. 

 p. 16; With. Arr. ed. 3, iv. p. 31. Brit. E<vs. : Larb. Lich. Hb. 

 n. 292. 



Well distinguished from both the preceding species by having the 

 thallus more closely appressed and somewhat pruinose, with the lacinife 

 more contiguous, naiTOwly sinuate and crenate at the margins. As men- 

 tioned by Acharius /. c., the lobes towards the centre of the thallus are 

 more rugose (var. rm/ositla Leight. Lich. Fl. p. 131, ed. 3, p. 121), especially 

 seen in old plants. The apothecia are chiefly central, and the spermogones 

 are not uncommon. They are rather prominent, brownish-black, with 

 spermatia 0,007 mm. long, 0,001 mm. thick. 



Hub. On the trunks of trees, rarely on rocks, in maritime and upland 

 districts. Distr. Local and scarce in the Char.nel Islands, S. and N. 

 England, N. Wales ; not yet seen in Scotland, nor with certaintv in Ire- 

 land. B. M. : Petit Port', Island of Jersey. Esher, Surrey; Glynde, 

 Sussex; near Ryde, Isle of Wight ; Lymington, Hampshire ; near Exeter 

 and Ilsham, Torquay, Devonshire ; near Barniouth and Harlech, Merion- 

 ethshire ; Clapdale, Yorkshire; near Kendal, Westmoreland. 



Subsp. P. carporhizans Cromb. Grevillea, xv. (1887) p. 75. 

 Thallus similar to that of P. tiliacea (K+y ellowish , CaCl~ red ). Apo- 

 thecia moderate, often excentrically perforate, badio-reddish, the 

 receptacle beneath black-setulose, the margin subentire or slightly 

 crenulate ; spores ellipsoid, 0,009-11 mm. long, 0,0046 mm. thick. 

 ParmeUa carporliizans Tayl. in Hook. Journ. Bot. vi. (1847) 

 p. 163 ; Cromb. Journ. Bot. 1882, p. 272. ParmeUa tiliacea Cromb. 

 Lich. Brit. p. 33 pro parte; Leight. Lich. Fl. p. 131 pro parte, ed. 3, 

 p. 121 pro parte. Lichen tiliaceus Eng. Bot. t. 700. 



When sterile, scarcely to be distinguished from P. tiliacea, but at least 

 a good subspecies, characterized by the short, blackish, setulose fibrils with 

 which the thalline receptacle of the fruit is densely clothed beneath. In 

 this respect, as pointed out by Taylor I. c., it is analogous to Physria ulo- 

 thrix. The apothecia are plentiful when they occur, and frequently be- 

 come perforate, though the perforations are not exactly in the centre, as 

 in P.perforuta, 



Hah. On the trunks of trees in wooded maritime and upland districts. 

 Distr. Local but not uncommon in S. England and the Channel Islands. 

 B. M. : Near Jerbourg, Island of Guernsey. Lymington, Hampshire ; 

 Chagford, Ashburton, and Cornworthy, S. Devon; Dunster Tower, 

 Somersetshire. 



