THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 239 



LXI. Buellia DeNot. 



Buellia DeNotaris, Giorn. Bot. It. an. 2: t. 1: 195. 1846. 



Thallus as above; apothecia innate, appressed, or sessile, lecideine, 

 not containing algae; hypothecium usually dark or black; paraphy- 

 ses simple, the tips generally dark and thickened; asci 8-spored, 

 rarely with 16-24 spores; spores brown to blackish, oblong or ellip- 

 soid, 2-4 locular, becoming muriform, the septa thick, without a 

 halo. 



A large genus, the species often very difficult; on bark, rocks, and 

 wood, occurring in all parts of the world. 



KEY TO THE SPECIES. 



A. Thallus dark. 



B. Thallus more or less squamulose i. badia 



BB. Thallus more or less compactly crustose or minutely 

 areolate. 



C. Brown-gray or umber 2. pullata 



CC. Greenish or brownish ash colored and darker. 3. myriocarpa 

 AA. Thallus pale. 



D. Thallus more or less yellowish. 



E. Yellow with CaCl 2 O 2 ; on trees 4. oidalea 



EE. Orange-red with CaCl 2 O 2 5. halonia 



DD. Thallus more or less whitish or ashen. 



F. Little or no reaction with KOH. 



G. Areoles small, rough-surfaced, angulose; KOH 



or brownish; on rocks 8. spuria 



GG. Thallus uniform or sub-areolate; clear white, 

 often silvery; KOH faintly yellowish or ; 



on rocks 6. albo-atra 



FF. Yellow with KOH. 

 H. On bark. 



/. Thallus of smooth, rounded, contiguous 

 areoles, occasionally sub-lobate; whitish 



to dark gray 7. parasema 



HH. On rocks. 



/. Without evident hypothallus. 

 K. Areoles distinct, putty-colored; more or less 

 sub-lobate or crenate at circumference. 



9. lepidasira 

 JJ. Hypothallus present. 



L. Areoles and apothecia minute to very 

 minute; apothecia innate-sessile,between 



the areoles 10. stellulala 



LL. Areoles and apothecia minute to small; 

 apothecia adnate upon the areoles. 



ii. retrovertens 



