PARMELIA.] PAEMELIEI. 251 



in the S.; very local in Central Scotland; not seen from Ireland. 

 B. M. : Saham Wood, Norfolk ; near Bury, Suffolk ; Epping Forest, 

 Essex ; Broome Park, Kent ; St. Leonard's Forest, Poyning's Hill, and 

 Beeding Priory, Sussex ; near Netley Abbey, Hampshire ; Somerford 

 Keynes, Wiltshire ; near Cirencester and Fairford, Gloucestershire ; near 

 the Ketch, Worcestershire ; Harboro' Magna, Warwickshire ; Stokesley, 

 Cleveland, Yorkshire. Auldbar, Forfarshire. 



21. P. olivacea Ach. Meth. (1803) p. 213. Thallus orbicular, 

 membranaceous, appressed, rugulose or minutely corrugate, laciniato- 

 loberl, subopaque, olive-brown or badious-umbrine ; beneath nearly 

 coucolorous, paler at the circumference, obsoletely fibrillose ; lobes 

 radiating, plane, rounded, crenate (K~, CaCl~). Apothecia mode- 

 rate, dark chestnut-coloured, the margin entire or nearly entire ; 

 spores 0,011-19 mm. long, 0,007-10 mm. thick. Nyl. Syn. i. 

 (1860) p. 395; Cromb. Grevillea, x. p. 24; Lich. Brit. p. 35 pro 

 parte ; Leight. Lich. Fl. p. 122 pro parte, ed. 3, p. 115 pro parte. 

 Liclicnoides olivaceum, scutellis Icvvibus Dill. Muse. 182, t. 24. f. 77 A. 

 Lichen olivaceus and Parmelia olivacea of our older authors belong 

 to one or other of the following allied plants. 



Several species, now rightly separated, have been included here by 

 authors. As limited, it is readily recognized by the rugulose thallus and 

 the entire margin of the apothecia. It is a plant of a more boreal type 

 than any of its immediate allies. The apothecia are chiefly central and 

 crowded, the margin of the receptacle becoming less smooth and entire 

 in age. The spermogones are minute, black, immersed or prominent, 

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



Hob. On the trunks of trees, birch and alder, in wooded upland dis- 

 tricts. Distr. Very local and rare in the N. Grampians, Scotland. - 

 B. M. : Abergeldie and Glen Clunie, Braeruar, Aberdeenshire. 



22. P. exasperata Nyl. Not. Siillsk. pro F. et Fl. F. Forh. n. s. 

 v. (1866) p. 120 (note). Thallus orbicular, membranaceous, mi- 

 nutely and densely rugoso-papillose, olive-brown ; beneath paler, 

 sparingly fibrillose ; lobes more or less obliterated in the centre, 

 appressed, rounded and inciso-crenate at the circumference (K~ 

 CaCl~). Apothecia small, or at length somewhat large, chestnut- 

 coloured, the margin elevated, verrucose and papillose ; spores shortly 

 ellipsoid, 0,009-12 mm. long, 0,007-10 mm. thick. Cromb. Journ. 

 Linn. Soc. Bot. xvii. p. 572. Parmelia olivacea subsp. exasperata 

 Cromb. Lich. Brit. p. 35 : var. exasperata Leight. Lich. Fl. p. 123, 

 ed. 3, p. 115. Collema exasperatum Ach. Lich. Univ. (1810) p. 645. 

 Parmelia olivacea Gray, Nat. Arr. i. p. 438 ; Hook. Fl. Scot. ii. 

 p. 52 ; Eng. Fl. ii. p. 200 ; Tayl. in Mack. Fl. Hib. ii. p. 143 ; 

 Mudd, Man. p. 99 pro parte. LicTien olivaceus fluds. Fl. Angl. 

 p. 446; Lightf. Fl. Scot ii. p. 819 pro parte ; With. Arr. ed. 3, iv. 

 p. 35 ; Eng. Bot. t. 2180. Lichenoides olivaceum, scutellis ampliori- 

 bt(s verrucosis Dill. Muse. 184, t. 24. f. 78. Lichenoides crusta 

 foliosa scutellata, pullum Dill, in Hay, Syn. ed. 3, p. 72, n. 60. 



