250 LICHEN AC F i. [PARHELIA. 



subglobose, sulphureous soredia ; beneath dark, with blackish 

 rhizinse; Iacinia3 narrow, multifid, somewhat convexo-compressed, 

 incurved at the apices (K~, CaCl~). Apothecia small, reddish- 

 brown, the margin subentire ; spores 0,008-12 mm. long, 0,005-6 

 mm. thick. 8m. Eng. El. v. p. 202 : Tayl. in Mack. El. Hib. ii. 

 p. 149; Mudd, Man. p. 102 ; Cromb. Lich. Brit. p. 34 ; Leight. Lich. 

 El. p. 140 pro parte, ed. 3, p. 129 pro parte. Lichen incurvus Pers. 

 in list. Ann. vii. (1794) p. 24. Parmelia recurva Ach., Gray, Nat. 

 Arr. i. p. 442 ; Hook. El. Scot. ii. p. 54. Lichen multifidus, Dicks. 

 Crypt, fasc. iii. p. 16, t. 9. f. 7 ; With. Arr. ed. 3, iv. p. 28. 



Easily recognizable from the allied species by the in curved apices of the 

 lacinise. The thallus, which is usually widely expanded, often becomes 

 subcrustaceous and dark in the centre, where also, in very old plants, it 

 sometimes decays like P. centrifuga, a plant not found in Great Britain. 

 The apothecia are very rare in this country, and when present are not 

 rightly developed. The spermogones, however, are frequent, giving the 

 thallus a black punctate appearance, with spermatia 0,005-7 mm. long, 

 about 0,001 mm. thick. 



Hob. On granitic rocks and boulders in subalpine and alpine places. 

 Distr. Local in S.W. Ireland and S. Scotland ; more frequent among the 

 N. Grampians, Scotland.- B. M. : New Galloway, Kirkcudbrightshire ; 

 Craig Coinnoch, Glen Candlic, Ben-naboord, Mo'rrone, and Upper Glen 

 Dee (fruit), Braemar, Aberdeenshire. Dunkerron Mt., co. Kerry. 



c. Oliraceo-nigricantes . Thallus normally olive-brown or 

 brownish-black. 



20. P. acetabnlum Dub. Bot. Gall. ii. (1830) p. 601. Thallus 

 orbicular, coriaceo-membranaceous, unequal or rugulose, subopaque, 

 imbricato-lobed, glaucous- or lurid-olivaceous ; beneath paler and 

 sparingly black-fibrillose ; lobes rounded, appressed at the circum- 

 ference, ascending and undulate in the centre (KT 11 j ]-, *^ n re( j 

 CaCl~). Apothecia moderate or large, rugose, badio-reddish, the 

 margin crenulate, inflexed; spores 0,012-16 mm. long, 0,008-10 mm. 

 thick. Mudd, Man. p. 99 ; Cromb. Lich. Brit. p. 35 ; Leight. Lich. 

 El. p. 136, ed. 3, p. 125. Lichen acetabulum Neck. Delic. (1768) 

 p. 506. Parmelia corrugata Gray, Nat. Arr. i. p. 438 ; Hook. Eng. 

 El. v. p. 201. Lichen corrugatus Eng. Bot. t. 1652. LicJienoides 

 acetabulis cutaneis et rugosis Dill. Muse. 185, t. 24. f. 79. Brit. 

 Exs. : Cromb. n. 142 ; Leight. n. 362. 



The thicker thallus, the larger lobes, and rugose apothecia readily dis- 

 tinguish this from our other species of this subsection. Elsewhere it grows 

 widely expanded, though this state is rare in Britain. The apothecia, which 

 are not frequent in this country, become rather large in very old plants. 

 The spermogones, generally very abundant, are at length confluent, and 

 form rugosities on the thallus, with the sterigmata often branched and 

 jointed, and the spermatia about 0,007 mm. long, 0,001 mm. thick. 



Hab. On the trunks of old trees in woods and parks in lowland 

 districts. Distr. Not general nor common throughout England, chiefly 



