THE IICHEN FLORA OF THE SANTA CRUZ PENINSULA 75 



DIPLOSCHISTACE^E. 



Thallus uniform crustaceous, corticated, attached to the substra- 

 tum by the hyphae of the hypothallus or of the medulla; alga Proto- 

 coccus. Apothecia circular, sunken in the thallus or appressed, 

 with crater- like, or finally flat disk; proper margin well developed, 

 entire, or only laterally developed; spores two- to many- celled or 

 muriform. 



XVIII. Diploschistes Norman. 



Diploschistes Norman, Con. Prae. Nov. Gen. Lich. 20. 1852. 



Thallus as above, as are the apothecia. Proper margin well 

 developed, black or clear; paraphyses simple or branched at the tips; 

 asci thin-walled, with 4 8 spores; these muriform, dark. 



KEY TO THE SPECIES. 



Apothecia medium-sized, from pit-like becoming open and plane with 

 broad disk, black or gray pruinose i. scruposus 



Apothecia minute, immersed, opening by a pore surrounded by a radiately 

 striate margin 2. actinostomus 



i. DIPLOSCHISTES SCRUPOSUS (L.) Norman. 



Lichen scruposus Linne, Mantissa, 2: 131. 1771. 



Diploschistes scruposus Norman, Con. 1852. 



Urceolaria scmposa Ach. Meth. Lich. 147. 1803. 



Urceolaria scruposa Tuck. Syn. North Am. Lich. I: 222. 1882. 



Thallus determinate to effuse, of rough, irregularly shaped, some- 

 times contorted and plicate, chinky or fissured areoles, forming a 

 thick and hard or more or less crumbly and mealy crust; KOH ; 

 CaCLO 2 reddish; color various shades of gray, whitish, and ashen; 

 rarely gray-brown and rusty. 



Apothecia numerous, from small and immersed becoming 

 superficial and medium-sized or large; from deep and pit-like finally 

 open, plane, with broad black disk, often gray pruinose; the thalline 

 margin thick, swollen, from entire to more or less rugose; the proper 

 margin arched, blackish, more or less denticulate; sometimes the 

 thalline margin disappears, when the proper margin becomes 

 prominent, thickened, and exceedingly fine, intricately entwined, 

 transverse striae become visible; paraphyses slender, branching, 



Proc. Wash. Acad. Sci., May, 1910. 



