CRYPTOGAMI ALICHENES. 9 1 



inches. It is very rigid when dry, and of a greyish-white or 

 green colour. The branches are generally fastigiate above, 

 dichotomous, smooth, pitted, and glossy, or very rough 

 with short processes and tubercles. The second variety 

 grows in erect rigid tufts, rarely exceedingly 2 inches in 

 height ; the fronds either simple or once or twice branched, 

 and roughened with tubercles, which appear to be imper- 

 fect or blighted apothecia. It seems to be the Lichen cali- 

 caris of LIGHTFOOT, 834, when he tells us that *' it will 

 dye a red colour, and promises, in that intention, to rival 

 the famous L. roccella or argol, which is brought from the 

 Canary Islands, and sometimes sold at the price of L. 80 

 Sterling per ton. It was formerly used instead of starch 

 to make hair powder." 



3. R. fastigiata, csespitose, compressed, branched, branches 

 smooth, pitted, thickened upwards and fastigiate ; apothecia ter- 

 minal HOOK. Scot. ii. 68. Lichen calicaris, LIGHTF. Scot. 834. 

 WITH. iv. 55. L. fastigiatus, Eng. Bot. t. 890. DILL. Muse. 

 t. 23. f. 62. 



Hab. On ash, thorn, and other trees, common. 



LIGHT FOOT has mixed up the descriptions of this and the 

 preceding under his Lichen calicaris. 



4. R. farinacea, oespitose, branched, branches compressed, li- 

 near, dichotomous, smooth, with farinaceous tubercles on the 

 edges HOOK. Scot. ii. 68. Lichen farindceus, LIGHTF. Scot. 833- 

 WITH. iv. 54. Eng. Bot. t. 889. DILL. Muse. t. 23. f. 63. 



Hab. On trees, very common ; also on stone walls and 

 rocks exposed to the sea, but in the latter stations small- 

 er and more bushy. 



This is very rarely to be found with apothecia, a state in, 

 deed in which I have not observed it, whereas the three 

 preceding species are as rarely to be found without them. 

 All the species are of the same uniform greyish-green or 

 white colour ; and all afford a mucilage or gum, which, in 

 an economical and medical view, may probably be equal to 

 that of Cetraria islandica. 



50. COHNICULARIA. 



1. C. aculeata, frond erect, shrubby, chestnut-brown, varnished ; 

 branches roundish, somewhat pitted, crowded, dichotomous, with 



