PHYSCIA. | PHYSCIET, 295 
somewhat prominent, yellowish or blackish; sterigmata very rarely 
subsimple. 
The species of this genus are diverse in habit, some being everniiform, 
a few subplacodioid ; but the larger number are parmelioid, They also 
vary somewhat in the structure of the cortical layer, the form of the 
spores, and the spermatia.” They agree, however, in what is more essential, 
the lecanorine apothecia. The colour of the thallus, here closely connected 
with differences in the fructification, enables us to arrange them under 
two sections, which are almost entitled to be regarded as subgenera. 
A, FLAVESCENTES.—Thallus yellowish. Apothecia concolorous ; 
spores polari-bilocular (the loculi usually connected by a 
thin tube),  colour- 
less. Spermogones 
yellowish, with sper- 
matia oblongo-ellip- 
soid. — Xanthoria Fr. 
Pl. Hom. (1825) p. 243 
pro parte. 
1. P. flavicans DC. FI. 
Fr. ii. (1805) p. 189.— 
Thallus subfruticuloso-fila- 
mentose, czespitose, very 
much and intricately 
branched, yellow or orange- 
yellow; beneath concolorous 
or subconcolorous, subcana- 
liculate; branches somewhat 
rounded, slender, attenuate, 
furcellate at the apices 
(Kt POPES, CaCl). Apo- Fig, 52, 
thecia lateral, small or Physcia parietina, De Not.—a. Vertical section 
moderate, plane, orange- of thallus, x 200. b. Theca and paraphysis, 
coloured, the margin thin, x 3800. ¢. Spores (mostly from the living 
plant), x 500. d. Section of spermogone, 
snbcrenulate ; spores some- yx 30. e. Jointed sterigmata and spermatia, 
times simple, 0,012-18 yx 500. f. Spores of P. ciliaris DC. x 500. 
mm. long, 0,007-11 mm. 
thick.— Mudd, Man. p. 112, t. ii. f. 33; Cromb. Lich. Brit. 
p. 87; Leight. Lich. Fl. p. 141, ed. 3, p. 180.—Parmelia flavicans 
Tayl. in Mack. Fl. Hib. ii. p. 147. Borrera flavicans Hook. FI. 
Scot. ii. p.57; Sm. Eng. Fl. v. p. 224. Lichen flavicans Sw. FI. 
Ind. Occid. ili. (1788) p. 1908; Eng. Bot. t. 2113. Borrera leta 
Gray, Nat. Arr. i. p. 485. Lichen vulpinus (non Linn.) Huds. Fl. 
Angl. p. 462; Lightf. Fl. Scot. ii, p. 896; With. Arr. ed. 3, iv. 
p. 49. Usnea capillacea citrina, fruticuli specie Dill. Muse. 73, 
t.13.f.16. Lichenoides quod Muscus aureus tenuissinus Dill. in 
Ray Syn. p. 65, n. 8.—Brit. Hvs.: Leight. n. 169; Mudd, n. 84; 
Larb. Ceasar. n. 21; Cromb. n. 48. 
A beautiful plant, easily recognized by the somewhat elongate orange- 
