LICHENES 437 



SERIES 1. GLAUCESCNTES. 



1. P. crinita, Ach. [Haired] : Thallus submembranaceous, 

 glaucous-fuscescent, and with the apothecia beset with isidioid (or 

 coral-like) granules and branchlets ; under side black, smoothish, 

 with here and there black fibres ; lobes plane, erose-crenate, ciliate ; 

 apothecia large, marginal, cyathiform, imperforate ; margin thin, 

 inflexed, finally explanate. 



Hob. On trunks of trees, and rails : common. 



2. P. perforata, Ach. [Perforated] : Thallus membranaceous, 

 smooth, greenish-glaucous; under side black, with dark fibres; 

 lobes rounded, ascendant, subcrenate, ciliate ; apothecia large, fun- 

 nel-form, rufous, perforate, very entire. 



ffab. On trees, and fences : very common. 



3. P. SCortea, Ach. [Leathery] : Thallus subcoriaceous, orbi- 

 cular, smooth, glaucous-white ; under side black, hispid-fibrillose ; 

 lobes rather long, appressed, sinuate-crenate, incised ; apothecia 

 rufous-fuscous, sub-entire. 



Hob. On trunks of trees, and rocks : frequent. 



Obs. This too nearly approaches the following, with which. 

 FRIES unites it. 



4. P. tilisicea, Ach. [Linden] : Thallus membranaceous, orbi- 

 cular, smoothish, glaucous-cinerascent ; under side blackish-fus- 

 cous, with black fibres ; lobes sinuate-lacinate, rounded, crenate ; 

 apothecia subfuscous, crenate, or very entire. 



Hob. Trunks of trees, &c. : very common. 



5. P. Borrrl, Turn. [Borrer^s]: Thallus cartilagineous- 

 membranaceous, orbicular, smoothish, glaucous-cinerascent (with 

 round, marginate soredia) ; under side fuscescent, fuscous-fibrillose ; 

 lobes rounded at the apices, naked ; apothecia chestnut, the margin 

 inflexed, entire. 



Far. b. rudecta, Tuckerm. MS. soredia immarginate ; the whole thallus beset with 

 isidioid granules and branchlets. 

 Hob. On trunks, &c. We have the var. only. 



6. P. saxatili, Ach. [Rock]: Thallus subcartilagineous, 

 reticulate-lacunose, glaucous-cinerascent; under side black and 

 fibrillose ; lobes sinuate, sub-retuse ; apothecia dark-chestnut, at 

 length crenulate. 



Hob. Rocks ; trees ; rails, &c. : common. 



7. P. aleurites, Ach. [Mealy] : Thallus membranaceous, orbi- 

 cular, continuous, rugose-plicate, becoming furfuraceous, glauces- 

 cent ; under side pale, with fuscous fibres ; lobes discrete at the 

 circumference, rounded, cut-crenate ; apothecia dark-fuscous, finally 

 crenulate. 



Hob. Trees; rails, and rocks : common. Often sterile. 



8. P. pliySJtles, Ach. [Bladder-like]: Thallus somewhat 

 inflated, glaucous- white ; under side naked, black-fuscous; lobes 

 loosely imbricate, linear, convex, sinuate-multifid ; apothecia red- 

 dish-brown, with an inflexed entire margin, finally explanate. 



TJab. Rocks ; trunks, and dead wood: frequent. Infertile with us. 



