P.VRMELI\.] I'ARMKIJF.I. 2o7 



usnallv almost simple and spermatia U.OOO-T mm. loiiG". 0,001 mm. tliiok, 

 .slifrhtiy subacute at the apices. 



Hah. On rocks and boulders, very rarely on <rravelly .soil, in subalpine 

 and alpine localities. — Distr. Local and .«carce in 8.W. and X. England 

 and in X. Wales ; more frequent on the Grampian.s, Scotland ; rarer in 

 W. Ireland. — B. M. : Dartmoor Tors, Devonshire ; Cader Idris, ^[erion- 

 ethshire ; Snowdon, X. Wales; Teesdale, Durham. Xew Galloway, 

 Kirkcudbrightshire ; Ben More, MaelGirdy, aud Ben Lawei's, Perthshire; 

 ( 'lova Mts. and Katehnv, P'ort'arshire ; I.,och Phadrig, Lochnagar, Mor- 

 roup. Cairngorm, and Ben-naboord (frt.), Braemar ; Ben Xevis, Inver- 

 ness-shire : Hills of Applecro.ss, Ross-shire. Maugerton, Killarney, and 

 Mac(Tillicuddy's Eeeks, co. Kerry ; Doughbruagh Mts., Connemara, co. 

 Galway. 



Tar. /3. reticulata Cromb. Grevillea, xii. (1884) p. 72 — Thallus 

 orbicular or suborbiciilar, closely apjuessed. black or blackish, opaque; 

 branches short, slendci', very much entangled, subimbricate, dicho- 

 tomously reticulate, shortly furcate at the apices. Apothecia con- 

 colorous, with the margin often ciliate. — Lichen retkulatus Wulf. in 

 Jacq. Coll. ii. (17SS) t. !*. if. 0, 7. Alectoria Janata var. parmelioidcx 

 Cromb. Journ. Bot. 1872, p. 233 ; Leight. Lich. Fl. ed. 3, p. 81 

 (incl. var. suhcUiata). Parmelia Janata var. subciJiata Xyl., Cromb. 

 Lich. Brit. p. 35 ; Leight. Lich. Fl. p. 125. Lichen puljcscens Huds. 

 Fl. Augl. ed. 2, p. 132 : Lightf. Fl. Scot. ii. p. 893 ; With. Arr. ed. 3. 

 iv. p. 48. CoralJoidex tenuissiinum ni.jrescens,munclimuJiehris instar 

 textum Dill, ilusc. 113, t. 17. f. 32.— Brit. Exs.: Cromb. n. 20. 



A well-marked variety, which in its normal condition with its parme- 

 lioid habit looks like a distinct species. Transition states, however, exist, 

 and old plants gi-adually assume more of the characters of the type. The 

 thallus, which is aptly compared bv Dillenius to " black lace,"' occasionally 

 becomes centrifugal. It is not uncommon in a fertile condition, the apo- 

 thecia being usually numerous, with the margin often ciliate with spinu- 

 liform papillae. 



Hob. On quartzose rocks and boulders in alpine localities. — Disfr. Con- 

 fined to some of the higher Grampians, Scotland, where it is plentiful. — 

 B. M. : Ben Lawers, Perthshire : Clova Mts., Forfarshire ; MoiTone, Glen 

 Callater, Cairngorm, and Gleu Candlic, Braemar, Aberdeenshire. 



29. P. tristis Xyl. Act. See. Linn. Bord. se'r. 3, i. (1856) p. 304; 

 Flora, 1872, p. 548. — Thallus cfespitoso-fruticulose, cartilaginous, 

 erect, rigid, somewhat roundly compressed, sparingly distichously 

 branched, pitch- or brownish-black ; branches subfastigiate, at- 

 tenuate (K~, CaCl~)" Apothecia plano-convex, moderate, sub- 

 concolorous, the margin entire or fimbriate ; spores U,U08-11 mm. 

 long, 0,004—6 mm. thick. — Cromb. GrevUlea, xii. p. 71. — PJatifsma 

 triste Cromb. Lich. Brit. p. 26 ; Leight. Lich. Fl. p. 99. ed. 3. p. 94. 

 CornicuJana tristis Gray, Xat. Arr. i. p. 404 : Hook. Fl. Scot. ii. 

 p. 69 : Sm. Eng. Fl. v. p. 228 ; Tayl. in Mack. Fl. Hib. ii. p. 86 : 

 Mndd, Man. p. 76. LicJien tristis Web. Spicil. (1788) p. 209 ; 

 AVith. Arr. ed. 3, iv. p. 43 ; Eng. Bot. t. 720. Lichen radiatns 

 Huds. Fl. Angl. ed. 2. n. -"joO. Lichen cornicnlatns Lightf. Fl. Scot. 



