106 CYCLOCARPINEE [STICTA 
Orver IX. STICTACEA. 
Thallus foliose, horizontal or somewhat ascending, corticate 
on both surfaces, beneath more or less tomentose. Cyphelle 
(minute cup-like hollows) or pseudo-cyphelle (openings in the 
cortex) constant on the under surface in Sticta, Cephalodia 
present in certain species. Algal cells blue-green (Nostoc) or 
bright-green (Palmellacez). Apotheecia marginal or scattered, 
scutellate and shortly stalked or sessile; paraphyses simple, 
septate; spores elongate, 2—pluri-septate, colourless or brown. 
Spermogones with septate sterigmata and short straight pleuro- 
genous spermatia., 
Resembling Peltigeracez in that both types of gonidia, blue-green 
and bright-green, are represented, and in the frequent presence of 
cephalodia in those species with bright-green algal cells. Cyphelle 
are small cup-like empty pits with a distinct rim that occur amongst 
the tomentum of the lower surface; pseudo-cyphelle are less 
definitely marginate and are filled with loose hyphe. 
Two genera are represented in Great Britain :-— 
Thallus with cyphelle or pseudo-cyphelle on the 
Under SULLACE 26... -0s0dswavendeenscuvens enw nienean teeta 35. Sticta. 
Thallus without these structures ..............seesscssereevese 386. Lobaria. 
35. STICTA Schreb. L. Gen. Pl. ii. p. 768 (1791). (Pl. 35.) 
Thallus foliose, variously lobate or laciniate, horizontal, 
sometimes slightly ascending or stalked and upright, cortex on 
both surfaces plectenchymatous ; beneath cyphellate or pseudo- 
cyphellate and pale- or dark-brown-tomentose, with single or 
fasciculate hyphe. Algal cells Nostoc or Palmellacez. Cephalodia 
rarely present. Apothecia marginal or scattered, with or 
without a thalline margin; paraphyses simple, septate; asci 
8-spored, the spores elongate, fusiform or acicular, 1—7-septate. 
Spermogones with septate sterigmata and pleurogenous spermatia, 
short and slightly thickened at each end. 
The genus is distinguished among foliose lichens by the minute 
round openings in the tomentose under-surface due to the presence 
of cyphelle or pseudocyphelle. 
It is divided into two sections, distinguished by the character of 
the alge :— 
Thallus with blue-green algw (Nostoc)...........ccceeeceee ees i. SricTrna. 
Thallus with bright-green alge (Palmellacew) ............ ii. Eusricra. 
§ i. Srictina Hue in Nouv. Arch. Mus. Hist. Nat. Paris, 
sér. 4, iii, p. 81 (1901). Stictina Nyl. Syn. Lich. p. 333 (1860) ; 
Cromb. Monogr. i. p. 265; Leight. Lich. Fl. p. 114. 
Algal cells blue-green. 
