164 LECANO-LECIDBEI [bACIDIA 



27. B. flavovirescens Anzi Cat. Lich. Sondr. p. 71 (1860). — 

 Thallus bright-greenisli-yellow, effuse, thin or thickish, finely- 

 granular or pulverulent (K — , CaCl — ); hypothallus filamentous, 

 dark-brown or blackish. Apothecia black, solitary or con- 

 glomerate, appressed, at first concave, then plane, with a 

 thickish obtuse margin, the disc granular ; hypothecium brownish- 

 black ; paraphyses slender, hyaline, greenish-yellow in thick 

 section ; spores acicular, pluriseptate, 0,036-100 mm. long, 

 0,003-4 mm. thick ; hymenial gelatine not tinged with iodine. — 

 Lichen flavovirescens Dicks. Crypt, fasc. iii. p. 13 t. 8, f . 9 

 (1793); With. Arr. ed. 3, iv. p. 12. L. citrinellus Ach. in Vet. 

 Acad. Handl. xvi. p. 135, t. 5, f. 5 (1795); Engl. Bot. t. 1877. 

 Lecidea citrinella Ach. Meth. p. 15 (1803) ; S. F. Gray Nat. 

 Arr. i. p. 466 ; Cromb. Lich. Brit. p. 94 ; Leight. Lich. Fl. 

 p. 339 ; ed. 3, p. 336. L. flavovirescens Borr. ex Hook, in Sm. 

 Engl. Fl. V. p. 178 (1833); Tayl. in Mackay Fl. Hib. ii. p. 122. 

 Baphiospora flavovirescens Koerb. Syst. Lich. Germ. p. 268 (1855) ; 

 Mudd Man. p. 186, t. 3, f. 70. 



Exsicc. Leight. n. 303. 



A conspicuous plant from the contrast between the brightly- 

 coloured, scattered or continuous thallus and the dark substratum, to 

 which it is loosely affixed. On account of the prominent, somewhat 

 carbonaceous margin of the apothecium, and the elongate-acicular 

 spores, it has been variously classified by authors under Lecanactis 

 or Baphiospora. Th. Fries (Lich. Scand. p. 343 (1874)) regards 

 B. flavo-virescens as a discomycetous fungus parasitic on the thallus 

 of Sphyridium byssoides (BcKomyces rufus). The gonidia, he 

 considers, belong to the latter plant, their bright colour being caused 

 by the action of the parasite on the host. Eehm has included it in 

 his genus Mycohacidiiim (Babenh. Krypt.-Pl. i. 3, p. 338 (1896)), but 

 states that the question of parasitism is by no means decided. 



Hab. On the ground and among mosses on rooks in hilly or sub- 

 alpine localities. — Distr. Apparently local, though plentiful where it 

 occurs in England and Wales, common in the Highlands of Scotland, 

 rare in Ireland. — B. M. Hay Tor, Dartmoor, Devon ; Builth, Breck- 

 nockshire ; Llyn Gwemon and Dolgelly, Merioneth ; Oswestry, Shrop- 

 shire ; Bettws-y-Coed, Carnarvonshire ; Llangollen, Denbighshire ; 

 Stavely, Westmoreland ; Teesdale, Durham ; near Helensburgh, Dum- 

 bartonshire ; Glen Creran, Argyll ; Glen Lochay, KUlin, Craig Galliach, 

 Ben Lawers, Eannoch and Craig Tulloch, Blair Athole, Perthshire ; 

 Canloohan Glen, Forfarshire ; Morrone, Braemar, Aberdeenshire ; 

 Hills of Applecross, Eossshire ; Wioklow ; near Dunkerron, Kerry ; 

 Doughruagh Mt., Connemara, Galway. 



Var. alpina A. L. Sm. — Thallus areolate, in crumb-like 

 masses, sublobulate at the circumference. Apothecia plane 

 or slightly convex, often congregate. — Lecidea flavovirescens 

 var. /3 alpina Schser. Spicil. Lich. Helv. p. 162 (1833). 



Distinguished by the more developed thallus. Lichen flavovi- 

 rescens var. 2, With. (I. c.) erroneously referred by Crombio 



