CRYPTOGAMIA ALG.^. 823 



Inflated Lichen. Anglis. 



Upon the trunks of old trees, upom rocks, and 



fometimes upon the gronnd. 

 The leaves are laxly imbricated, and frequently 

 grow in a circle. They arc variouQy divided, 

 and terminated with obtufe bifid, and fometimes 

 palmated, lobes j their upper furface convex and 

 white, their under one black and fmooth. But 

 what diftinguilhes this Lichen more particularly 

 is, that all the leaves and their fegments are hol- 

 low, or compofed of two membranes, a little 

 dillant from each other. I'he extremities of 

 the fegments in the younger leaves are inflated, 

 the membranes which compofe them being 

 united at the end, fo that if thofe extremities 

 are cut tranfverfely with a penknife, the two 

 membranes will be diftindly feen, and a cavity 

 between them. 

 The extremities of the old leaves are open, and 

 the upper membrane a little extended, waved 

 on the edges, and covered with a white farina- 

 ceous powder -, fometimes alfo the edges of all 

 the fegments arc covered with the like powder. 

 This is probably one of the fcxes, as, accord- 

 ing to Dillenius, it docs not produce ihields. 

 Other fpecimens, which have no powder, produce 

 fhiclds of a rcddilh brown colour, ftanding on 

 very ihort footftalks, their outfid« of the colour 

 of the leaves. Thefe fniclds are fcldom to be 

 found. 



L; im- 



