ROCCELLA. 



131 



colouring matter, called wulpmic acid, which is easily ex- 

 tracted by various solvents, and has been used in Sweden 

 and Norway to dye woollen stuffs. The Swedes call this 

 species "Ulf-mossa" (Wolf's-moss), from a belief that it is 

 poisonous to wolves; this is very problematical, but cer- 

 tain it is that it is used as a poison to these animals : Pon- 

 toppidan states that the bait is usually the carcase of some 

 animal smeared and stuffed with a mixture of this Lichen 

 in a powdered state, and pounded glass. 



Genus II. ROCCELLA, DC 

 Gen. Char. Thallus fruticulose, segments springing from a com- 

 mon base, round or thong-like, equal or nodulose, erect or pen- 

 dulous, glaucous, everywhere of similar colour, having a cartilagi- 

 nous cortical layer : very frequently sorediiferous. Apothecium 

 scutellate, its exciple being innate in the thallus, normally lateral. 

 Thalamium at first covered by a thalline veil, afterwards naked, 

 black. 



Generic term derived from the Portuguese word rocha, 

 a rock, in allusion to the habitat of most of the species ; 

 or from the name of the family of the Florentine merchant 

 (Oricellarii, or Rucellai) who was the first to manufacture 

 from them the now familiar dye Orchitt. 



