1922.] REVISION OF CALIFORNIA ARCTOSTAPHYLI 81 



Mt.)» Lake Co., Jepson. The note in Erythea, 3:178, was an in- 

 advertence. 



7. A. pungens H. B. K. This species is not uncommon on the 

 plateau of Mexico at 7000 to 8000 feet. It ranges northward through 

 Arizona into California, at constantly decreasing altitudes as it 

 moves northward, though keeping to the tops of the mountains. 

 With us it appears to be rather rare, but its range is in harmony with 

 the geographic distribution of plants entering California from the 

 southward. 



It is to be pointed out that material from California referred to 

 A. pungens is with difficulty differentiated from A. manzanita. A. 

 manzanita, however, occupies a distinct geographical area; and it 

 is retained as a species because it represents a different phase from 

 A. pungens in our manzanita series. 



The following specimens from California can be cited as ex- 

 amples: Onstatts Valley, San Jacinto Mts., Hall; Pecacho Peak, s. 

 Benito Co., Hall 9947. The plants of Marin Co. (which grow along 

 the high ridges of the Mt. Tamalpais region and which have been 

 known as A. montana Eastw.) agree well in pubescence, leaves and 

 other characters with the Southern California specimens just cited 

 and I hold them to be conspecific. Some of them show well, tho not 

 in the extreme form, the characteristically short and abrupt but 

 very sharp point to the leaf apex (Rock Spr., Jos. Saunders; Mt. 

 Tamalpais, Jepson 4761 ; Bill Williams trail, Jepson 9504) ; in other 

 specimens this structure is less marked (Lagunitas, Chestnut & 

 Drew; near Cypress Grove, Mt. Tamalpais, Jepson 6806), just as in 

 some of the specimens from Mexico. 



Fine examples of this Marin Co. form as it occurs on Mt. Tamal- 

 pais may be seen along Bill Williams trail between the Mountain 

 Theater and West Peak. One individual is fairly typical and is 

 noteworthy for its size and remarkable for its habit of growth. This 

 individual is quite erect, 63^ feet high, and with an open crown re- 

 calling A. manzanita. After having attained its height maturity, it 

 then, under some stimulus, threw out elongated lateral stems from 

 the trunk base. These strong stems are very long, very densely 

 branched in the top, and form or complete a low broad crown to 

 the shrub, gently sloping to the ground from the center. The 

 shrub as thus amplified is 24 feet in diameter and very thick and 

 smooth, except in the center occupied by the original or first erect 

 growth. 



Although out of harmony with the general distribution in Cali- 

 fornia, a specimen from Big Silver Creek, El Dorado Co. {Kennedy 

 228), is included here with some doubt. 



Refs. — Arctostaphylos pungens H. B. K. Nov. Gen. & 

 Sp. 3: 278 (1819), type loc. mt. slopes near Mexico City. A. mon- 

 tana Eastw. Proc. Cal. Acad. ser. 3, Bot. 1:83 (1897), type loc. 

 trail betw. Eldridge grade and Larsens, Mt. Tamalpais, Eastwood; 

 1. c. 1:127 (1898). 





