LECANORA.] 



LKCANO-I.KCIUKEr. 



40'J 



Differs from the preceding species in tlie colour of the thdllus and liypo- 

 thalhis, in the cliaracter of tlie thalline niartrin, and in the simple spores. 

 The papill;e of the thallus, which is either orbicular or somewhat ex- 

 panded, are minute, very much crowded, rather fra^'ile, and form a some- 

 what thickish and superticially firanulose crust. In moister situations it 

 is more greenish, its usual condition with us ; whence form Kjtod^jihoia 

 Cromb. (Parmelia spodophcpa Wahl. in .Vch. Meth. Suppl. p. '.>1). The 

 apothecia are numerous and crowded, with the thalline margin persL-stent 

 and (except in very young apothecia) always crenulate. 



Hab. On granitic and schistose rocks in maritime districts. — Distr. 

 Local, though usually plentiful in the Channel Islands, JS.W. England, 

 and N.E. Scotland. — B. M. : Le Fret, Island of Jersey. Tolpedn Pen- 

 with, and near Penzance, Cornwall. Portlethen, Kincardineshii-e. 



h. Thallus uniform, K + . 



86. L. subfusca Xyl. Flora, 1872, p. 250, nota 2.— Thallus deter- 

 minate, thin, subsmooth, or slightly rugoso-uuequal, whitish (K-H 

 yellowish, CaCl — ). Apothecia moderate, 

 plane or somewhat convex, brown or reddish- 

 brown, opaque or somewhat shining, the 

 thalline margin entire ; paraphyses slender, 

 discrete, brownish at the apices ; epithecium 

 non-granulose ; spores 0,011-16 mm. long, 

 0,007-10 mm. thick ; hymenial gelatine 

 bluish, then dark-violet (the thecse dark 

 tawny-coloured) with iodine. — Cromb. Gre- 

 villea, xviii. p. 68. — L.snbfusca form argen- 

 tata Cromb. Lich. Brit. p. 51 ; Leight. Lich. 

 Fl. p. 201, ed. 3, p. 186. L. subfusca y. 

 glabrata Mudd, Man. p. 146 pro parte, 

 L. subfusca Hook. Fl. Scot. ii. p. 47, Sm, 

 Eng. Fl. V. p. 189, is a nomen vagum pro 

 maxima parte (ut videtur). — Brit. Exs. : 

 Larb. Lich. Herb. n. 217. 



Fig. 65. 



Lecanora suhfusca Njl. — 

 a. A spore and jjara- 

 physis, X 350. b. 8te- 

 rigmata and spermatia, 

 X 500. 



A species until recently ill-defined and not well limited, several of 

 those which immediately follow being either confounded with it or 

 viewed simply as varieties. These are now separated chiefly by dif- 

 ferences in the paraphyses and epithecium, and also, according to 

 Nylander I. c, in the size of the spermatia. The typical state includes 

 Lecanora subfusca a. arcfentata Ach. Lich. Univ. p. oDS, and y. c/labrafa 

 Ach. I. c, which do not difter from each other. The apothecia are usually 

 more or less crowded, rarely somewhat scattered. The spermogones have 

 the spermatia 0,016-19 mm. long (Jide Nyl. in lift.), and in this, as in the 

 allied species, are black above. 



Hab. On trunks of trees, rarely on old pales, in maritime and lowland 

 tracts. — Distr. Seen only from a very few localities in E., S., and W, 

 England ; no doubt to be detected elsewhere. — B. M. : Lyndhurst, New 

 Forest, Hants ; Ilsham, Torquay, S. Devon ; near Cambridge: Churchill, 

 near Worcester. 



