LICHENACEiE. 



STICTA. 



Thallus foliaceous, coriaceo-cartilaginous, spreading, lobed, 

 free and downy beneath, with little cavities or hollow spots 

 (cyphellae) often containing a powdery substance. Shields (scu- 

 tella) beneath formed of the thallus, to which they are appressed 

 and fixed by a central point, the disk coloured, plane, surrounded 

 by an elevated border formed of the thallus. 



1S31. S. pulmonacea Ach. syn. 233. Hooker B. F. ii. 206. 

 — Lichen pulmonarius E. Bot. t. 572. — On the trunks of trees 

 in mountainous countries, frequently investing them with its large 

 shaggy looking fronds. 



Thallus wide spreading, olive-green, pale brown when dry, pitted and 

 reticulated, smooth or bearing powdery whitish warts in the reticulations, 

 and frequently elongated, bearing scattered or tufted granules ; deeply 

 laciniated and broadly lobed and sinuated, beneath clothed with brown- 

 ish downy fibres, the swellings bare. Shields mostly marginal, red-brown 

 with a thick border. — Employed in pulmonary affections ; its nutritious 

 properties resemble those of Cetraria islandica. In Siberia it is used 

 for giving a bitter to beer. 



PELTIDEA. 



Thallus foliaceous, coriaceous or membranaceous, spreading, 

 lobed, with woolly veins beneath, the lobules fertile. Shields 

 (peltae) suborbicular, adnate on the upper side of the lobules or 

 proper portions of the thallus and having a border formed of the 

 thallus. 



1332. P. aphthosa Ach. syn. 238. Hooker B. F. ii. 215. — 

 Lichen aphthosus E. Bot. 1. 1119. — Moist shady alpine rocks 

 among moss, and generally near water. 



Thallus bright green, smooth, sprinkled with brown warts, and having 

 broad rounded lobes, the fertile ones contracted, their sides reflexed. 

 Shields large, ascending, red brown with a jagged border. — Said to be 

 purgative, and anthelmintic. 



GYROPHORA. 



Thallus foliaceous, coriaceous or membranaceous, fixed by 

 the centre, peltate. Shields (tricae or gyromata) orbicular, sub- 

 scutelliform, sessile and adnate, covered by a black membrane, 

 the disk marked with concentric circles or plicae, with a border 

 of its own substance. 



1 333. G. proboscidea Ach. syn. 64s E. Bot. t. 2484. Hooker 

 B. F. ii. 217. — Mountain rocks. 



Thallus simple, membranaceous, rugose, with elevated reticulations of 



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