LECAXORA.] 



LECANO-LECIDEEI. 



487 



192. L. Heppii Xyl. ]S T ot. Sallsk. pro F. et Fl. Fenn. Forh. n. s. v. 

 (1866) p. 182. Thallus effuse, very thin, continuous, greyish-white 

 or sordid-ochraceous (K , CaCl ). Apothecia minute, concave, 

 brown, the margin entire, at length inflexed ; epithecium gyalectoid- 

 impressed ; paraphyses slender, not discrete; spores oblongo-ellipsoid, 

 0,0040-45 mm. long, 0,0015-20 mm. thick; hymenial gelatine 

 bluish, then wine- or sordid-wine-red with iodine. Cromb. Lich. 

 Brit. p. 57. Lecanora squamulosa forma Heppii Leight. Lich. Fl. 

 ed. 3, p. 170. Acarospora cervina 0. Heppii Mudd, Man. p. 160. 

 Myriospora Heppii Naeg. in Hepp, Exs. (1853) n. 37. Lecanora 

 squamulosa forma privigna Leight. Lich. Fl. ed. 1, p. 185 pro parte. 

 Brit. Exs. : Leight. n. 196. 



A rather inconspicuous plant very apt to be overlooked. It is apparently 

 a distinct species, though its claims to be so have at times been questioned. 

 The thallus is often scarcely visible aud, as observed by Th. M. Fries 

 (Licb. Scand. p. 218), is rarely minutely verruculose. The form of the 

 minute, usually numerous apothecia give it much the aspect of some 

 young Gyalecta. 



Hub. On arenaceous and calcareous rocks and flints in maritime and 

 upland situations. Distr. Only a few localities in England and S. Wales. 

 B. M. : South Downs, Hastings, and Bexley Hill, Sussex ; Lyndhurst, 

 New Forest, Hants ; Great Ayton, Cleveland, Yorkshire. Llandrindod, 

 Radnorshire. 







Q. Apothecia normally lecideine ; thecaa myriospored ; spores simple, 

 minute, colourless. Spermogones with simple sterigmata, at- 

 tenuate at the apices, and ellipsoid, very minute spermatia. 

 (Sarcogijne Mass. Geneac. (1854) p. 10.) 



193. L. pruinosa Nyl. in 



Cromb. Lich. Brit. (1870) p. 57. . > 



Thallus very thin, leprose, 

 greyish-white (K , CaCl), 

 usually obsolete. Apothecia 

 moderate, appressed, plane, 

 reddish-black when moist, black 

 and more or less cajsio-pruinose 

 when dry, whitish within, the 

 margin thin, entire, sometimes 

 undulate ; hypothecium thin, 

 subincolorous; paraphyses slen- 

 der, not discrete, brown at the 

 apices ; spores oblongo-cylin- 

 drical, 0,005-6 mm. long, 

 scarcely 0,0003 mm. thick ; 

 hymenial gelatine bluish, then 

 wine-red with iodine. Cromb. 

 Grevillea, xix. p. 58. Lecanora 



glaucocarpa forma pruinosa Leight. Lich. Fl. p. 183 ed 3, p. 168. 

 Lecidea pruinosa Sm. Eng. Fl. v. p. 179 ; Tayl. in Mack. Fl. Hib. 



X-500 



Fig. 63. 



Lecanora pruinosa Nyl. A. A theca 

 with paraphysis (separated by K), 

 X350. B. Three spores, X 350. 

 C. Sterigmata and spermatia, x 500. 



