332 I.ICHENACEI. [GYROPHOHA. 



Bot. t. 1282. Lichenoides tenue pullum, foliis utrinque glabris Dill. 

 Muse. 225, t. 30. f. 129. Brit. Exs, : Leight. n. 313; Mtidd, n. 87; 

 Larb. Lich. lib. n. 331. 



A rather variable plant in its manner of growth, whence different states 

 have been regarded by authors as more or less distinct varieties. In 

 nature, it is originally monophyllous, consisting of a single small peltate 

 leaf (form monophyua Turn. & Borr. /. c. ; Leight. //. cc.), which subse- 

 quently becomes more or less lobed and polyphyllous. Sometimes the 

 lobes become deeply divided and lacerate at the margins (form lacera 

 Leif-ht. Lich. Fl. p". 150, iii. p. 144; Mudd, Man. p. 116; Cromb. Enum. 

 p. 41). At other times the upper surface is occasionally marked by a few 

 undulating cracks with black interstices (form sulcata Turn. & Borr. I. c. ; 

 Leight. Lich. Fl. //. cc). Both of these, however, are but mere states, 

 and may be seen in the same specimen, so that they are not entitled to 

 be regarded as distinct forms. The apothecia seem to be extremely rare 

 in Great Britain. 



Hob. On rocks, boulders, and walls in upland and subalpine districts. 

 Distr. General and not uncommon in the mountainous regions of Great 

 Britain ; apparently rare in those of E. Ireland. B. M. : Dartmoor, 

 Devonshire ; near St. Clear, Cornwall ; Charnwood Forest, Leicester- 

 shire ; Cader Idris, Cellfawr, near Barmouth, Merionethshire ; Carnedd 

 Llewelyn, Carnarvonshire; Ingleby and Battersby Moors, Cleveland, 

 Yorkshire ; between Hyshope and Wasterly, Durham ; Kentmere, West- 

 moreland ; near Wallington, Northumberland. New Galloway, Kirkcud- 

 brightshire ; Ben Lomond, Stirlingshire ; Ben Lawers, near Tummel 

 Bridge, and Craig-y-Barns, Duukeld, Perthshire ; Sidlaw Hills, Clova 

 Mts., and Cortachy, Forfarshire ; Craig Coinnoch, Glen Callater, Morrone, 

 and Lochnagar, Braemar, Aberdeenslrire ; Ben Nevis, Inverness-shire. 

 Luggelaw, co. Wicklow. 



Form 1. glabra Nyl. ex Stiz. St. Gall. Nat. Gee. 1876, p. 212. 

 Thallus larger, monophyllous, somewhat firm, slightly rugulose, the 

 margin undulate and unequally inciso-lobed. Uyropkom glabra 

 Gray, Nat. Arr. i. p. 476 ; Hook. Fl. Scot. ii. p. 41. Lichen glaber 

 Ach. Prodr. (1798) p. 144 pro parte. Lichen anthracinus Dicks. 

 Crypt, fasc. iii. p. 19 ; With. Nat. Arr. ed. 3, iv. p. 63. 



Differs in the rather thicker, less smooth, and larger thallus (2-3 in. 

 broad), which is not polyphyllous, though more or less lobed at the cir- 

 cumference. Elsewhere the normally brownish-black colour of the thallus 

 merges into greyish (leaden-black), but this is not visible in our few 

 British specimens. With us it is always sterile. 



Hab. On rocks and boulders in upland mountainous districts. Distr. 

 Seen only sparingly among the Grampians, Scotland, and in E. Ireland ; 

 no doubt to be detected elsewhere. B. M. : Ben Lawers, Perthshire ; 

 Loch Callater, Braemar, Aberdeenshire. Lough Bray, near Dublin. 



Form 2. congregata Turn. & Borr. Lich. Br. (1839) p. 214. 

 Thallus very small, the lobes clustered and curled, with the margins 

 erect or reflexed, entire or lacerate. Cromb. Grevillea xv. p. 79. 

 Umbilicaria polyphylla form congregata Leight. Lich. Fl. p. 156, 

 ed. 3, p. 144. Umbilicaria varia a.polyphylla b. congregate Leight. 

 Ann. Mag. Nat. Hist. ser. 2, xviii. p* 279. Brit. L\vs. : Leight. 

 n. 65. 



