THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA I4I 



Thallus orbicular, flattish, much thinner than L. hildebrandii, \ohes 

 large, round, somewhat plaited. Color greenish black with very 

 small black granules more or less thickly sprinkled over the surface; 

 beneath pale, smooth, very minutely pubescent. 



Sterile. 



On trunks of trees, rare. So far collected only on Black Moun- 

 tain, at an elevation of 2200 feet. 



A Hchen of general distribution in the north temperate and sub- 

 arctic zones, very rarely found fruiting. 



4. LEPTOGIUM PLICATILE (Ach.) Nyl. 



Lichen plicatilus Ach. Nov. Att. Acad. Sci. Stockh. 16: 11. pi. i. f. 



2- 1795- 

 Leptogium plicatile Nylander, Cromb. Journ. Bot. 336. 1874. 

 Collema plicatile Ach. Lich. Univ. 635. 1810. 

 Collema plicatile Tuck. Syn. N. Am. Lich. 1 : 151. 1882, 

 Collema plicatile Herre, Proc. Wash. Acad. Sci. 7: 378. 1906. 



Thallus small, orbicular, thick, laciniate; divisions distinct, 

 separate, or disappearing centrally, leaving only the marginal lobes; 

 these rugose, undulate-pUcate, compact, more or less ascendant; sur- 

 face sometimes covered with small erect granules or lobules; color 

 dingy brownish green or black. 



Apothecia small or medium, numerous, concave or usually plane; 

 disk reddish or more often blackening, the margin entire or flexuous; 



7-5 — 8 

 spores ovoid, elUpsoid, quadrilocular, -^^ fi. 



On limestone rocks near the summit of Black Mountain, altitude 

 2700 feet, and on similar rocks at New Almaden, at about 1200 feet; 

 rare. 



Foimd in Europe from Sweden southward into northern Africa. 

 In America recorded only (so far as I am aware) from Iceland and 

 from the Santa Cruz Peninsula. 



5. LEPTOGIUM SCOTINUM (Ach.) E. Fr. 



Lichen scotinus Ach. Lich. Suec. Prodr. 128. 1798. 



Collema scotinum Ach. Lich. Univ. 651. 1810. 



Leptogium scotinum E. Fries, Sum. Veg. 122. 1846. 



Leptogium scotinum Herre, Proc. Wash. Acad. Sci. 7: 380. 1906. 



