LECANORA.] LFXAXO-LECIDEEI. 443 



or testacco-rcddish, ihe thallinc margin thickish, cronate ; sfwjres 

 fllipsoid, 0,UO'J-11 mm. long, 0,0015-8 mm. thick; paraphyses 

 moderate, granulato-inspersed, uot very discrete, epithecium brown- 

 ish ; hymenial gelatine bluish, then yellow (the thecui tawny- 

 yellow) with iodine. — Cromb. Journ. Lot. 1»74, p. 148 ; Leight. 

 Lich. Fl. ed. 3, p. 18+. 



More cl'jsely allied to L. subventusa Xyl., a North- American plant, 

 than to any Jjritish species of this section. In the two specimens seen 

 tlie thiiUus is more or less scattered, with the hypoth alius scarcely visible. 

 The apotht'cia in these are either scattered or crowded ; the spermogones 

 are seldom present. 



Hah. Ou granitic rocks in a maritime district. — Distr. Only sparingly 

 in the Chmuel Islands; (erroneously recorded by Leighton from N.W. 

 Irehmdj. — ii. M. : Vale Castle, Island of Guernsey. 



e. Thecae polyspored. 



133. L. Sambuci Nyl. Lich. Scand. (1861) p. 108.— Thallus 

 eft'use, very thin, granulose or subleprose, whitish or greyish, often 

 nearly evanescent (Kf+ yellowish, CaCl — ). Apothecia mintite, 

 jdane, brown or reddish-brown, the thalliue margin persistent, more 

 or less crenvdate, white; spores 12-16-3i;nte (rarely Snte), ellipsoid, 

 0,008-12 mm. long, 0,005-7 mm. thick ; hymenial gelatine bluish, 

 then pale-violet with iodine. — Carroll, Journ. Bot. 18u6, p. 23 ; 

 Cromb. Lich. Brit. p. 53 ; Leight. Lich. Fl. p. 186, ed. 3, p. 171. 



A rather inconspicuous plant resembling L. Hcufeni, from which it is 

 well distinguished by the numerous spores. These in the single British 

 specimen seen are usually 12nae, though they vary in plants from other 

 countries from 8na) to 32n8e in the same apothecium. The thallus, 

 when whitish, gives a positive reaction with K, as stated by Th. M. Fries 

 ( Lich. Scand. p. 248), but this is scarcely visible in our specimen, in 

 which the thallus is nearly evanescent. 



Hub. On trunks of trees, chiefly poplars, in upland tracts. — Distr. Very 

 sparingly among the S. Grampians, Scotland, and in X.E. Ireland (co. 

 Armagh.). — B. M. : Craig Calliach, Perthshire. 



F. Apothecia usually biatoroid ; spores Snae or 16nfe, simple or 1-3- 

 septate, colourless ; hymenial gelatine variously tinged with 

 iodine. Spermogones with simple sterigmata and arcuate 

 spermatia. (Lecania Mass, .Alcun. Gen. (1853) p. 12.) 



134. L. erysibe Xyl. Mem. Soc. Cherb. t. v. (1857) p. 114, Lich. 

 Scand, p, 167. — Thallus effuse, thin, diffract, leproso-granulose, 

 greyish- or greenish-olive, or sordid-greyish (K — ,CaCl— ), Apo- 

 thecia small, innato-sessile, plane or convex, brownish-red or Uvid- 

 testaceous, the thalline margin little distinct or evanescent ; spores 

 oblongo-ellipsoid, simple or often thinly 1-septate, 0,010-16 mm, 

 long, 0,004-6 mm, thick ; hymenial gelatine bluish with iodine. — 

 Cromb, Lich. Brit, p, 53 ; Leight, Lich, Fl, p. 2'2S, ed. 3, p. 218. — 



