140 COEYLACE^. 



finely twiggy; leaves narrowly or broadly ovate to elliptic, 1 to 4 in. 

 long, serrulate as in the last, but the teeth narrower and often salient, 

 or else very low; staminate aments 3 to 4 in. long, more slender than 

 in the preceding; bracts obtuse; filaments often more than 1 line long; 

 pistillate aments 2 or 3 lines long; cones broadly oblong, J to f in. 

 long, the bracts with a straight or only slightly upturned point; seeds 

 slightly larger that in the last, acutely margined. 



Sierra Nevada, and from the banks of the Sacramento Kiver west- 

 ward through the Coast Eanges to the ocean. Jan. -Feb. Our only 

 other species, A. tenuifolia Nutt., forms shrubby thickets at 6,000 to 

 7,000 ft. altitude in the Sierras. 



In the genus Betula, the stamens are 2 with forked filaments (each 

 fork bearing an anther cell); the bracts in the pistillate ament fall 

 from the axis when the cone is ripe, and the nutlet is broadly winged. 



B. occiDENTALis Hook., Western Birch; leaves ^ to IJ in. long. — 

 High Sierras and Humboldt Co. northward to Siskiyou Co. 



B. GLANDULOSA Michx.; a low bush with leaves J to 1 in. long. — 

 Plumas Co. and northward. 



16. CORYLACE/E. Hazel Family. 



Shrubs or bushes with alternate simple leaves. Staminate flowers 

 in aments without perianth. Pistillate fiowers in a short spike, 2 to 

 each bract and with small bractlets which become much enlarged and 

 foliaceous, forming a tubular involucre enclosing the nut. 



1. CORYLUS L. Hazbl. 



Leaves broad, thin, serrulate or incised. Staminate aments (cat- 

 kins) pendent, cylindrical, single or fascicled, from scaly lateral buds, 

 the pistillate clusters of flowers terminal and lateral on the same 

 branchlets. Plowers appearing before the leaves. Staminate flower 

 consisting of 4 (seemingly 8) stamens with forked filaments, each fork 

 bearing one cell of an anther, the undivided portion of the filament 

 cohering more or less with the inner face of the scale or bract of the 

 ament. Pistillate fiowers several in a scaly bud, two to each bract, 

 each flower with a posterior and anterior bractlet, these very small 

 but conspicuously laciniate-fringed; perianth minute, adnate to the 

 ovary and without limb; style short; stigmas elongated and slender. 

 Nut ovoid or oblong, large, bony, enclosed in a leaf-like involucre 

 formed of the enlarged bractlets. (Name said to be from korus, a 

 helmet, in reference to the involucre.) 



1. C. rostrata Ait. var. Californica A.DC. Califork^ia Hazel. 

 Commonly 6 to 10 ft. high; leaves broadly obovate, ovate or oval, 

 glandular-pubescent or villous, 1^ to 2J in. long; bract or scale of the 

 ament with its terminal portion abruptly turned upward; filaments, 

 save for the forked portion, obsolete or not evident, so that the stamens 

 are apparently 8 instead of 4; anthers with a sparse tuft of hairs at 

 apex; involucre densely hispid, prolonged beyond the nut into a 

 laciniately-fringed beak 1 in. long; nut 6 lines long. 



