THALLOGENS. 21 _ LICHENALS. 
lobes. Shields roundish, attached to the upper side of the lobes, 
and having a border formed of the thallus. 
1. P. canina Acharius—(Doe Licusn. Grovnp Liverwort.) Fig. 41. 
Thallus thick, glaucous grey, greenish when moist, somewhat furrowed, 
with rounded lobes, beneath white, with branching veins and fibres ; 
shields vertical, revolute, reddish brown, with a crenulate border. 
Habitat. On the ground, among moss, &c. 
Uses. An imaginary remedy for hydrophobia. 
2. P. aphthosa Acharius.—(Turusu Licuen.) Fig. 40. 
Thallus light green, smooth, sprinkled with brown warts; lobes broad, 
rounded, the fertile ones contracted ; shields large, red-brown, with a 
jagged border. ; 
Habitat. Moist alpine rocks. 
Quality. Purgative, anthelmintic. The Swedes boil it in milk as a cure for aphthe. 
CEeTRARIA. Acharius. 
Thallus leafy, spreading or erect, lobed and lacerated, smooth on each 
side. Shields orbicular, attached ob- 
liquely to the edge of the thallus, 
planoconcave, bordered by the inflexed 
thallus. 
1. C.islandica Acharius.—(IceLanD Moss.) 
Fig. 43. 
Thallus erect, tufted, olive-brown, paler on 
one side, lacerated, channelled, and 
bordered with  tooth-like fringes ; 
shields brown, with a raised border. 
Habitat, On the ground, i ions. 
Quality. Diliagteea, decclsent. ante tee 
Uses. A light diet for invalids, and a mild tonic. ; 
Phthisis, chronic catarrh, dyspepsia, chronie diarrhoea, dysentery.— Pereira, 
Roccetna. Acharius. 
Thallus between leathery and cartilaginous, branched and cut, erect, terete. _ 
aoa orbicular, adnate, plano-convex, with a thickened elevated 
border, 
1. R. tinctoria De Candolle—(Orcun. Arcuit. Dyer’s Moss.) _ 
Thallus suffruticose, branched, terete, erect, greyish brown, bearing 
powdery warts; shields almost black and pruinose, with a scarcely 
raised border ; juice deep yellow. ; 
Habitat, Rocks near the sea, especially in southern places. 
ae : ea: Dyes purple. 
manufacture. 
2. R. fuciformis De Candolle.—(Fiat Orca.) Fig. 38. es ee 
-Thallus flat, branched, nai greyish white, with powdery warts; = 
Sap not yellow. oS a 
Aabitat, Quatity, éec., like the preceding, but, according to the Rev. Mr. Salway, very 
ior as a dye. ee 
Fig. 43.—Cetraria islandica; natural size, 
_ Uses. Formerly used for preparing Litmus paper. Dyes various articles of . 
