OAK FAMILY. 143 



the higher mountain slopes or in the valleys. It is exceedingly vari- 

 able in the size, outline and lobation of the leaflets, but may be 

 recognized even at a distance by the characteristic blue color of the 

 foliage whence the common name by which it is most generally 

 known . The species was first collected by David Douglas, a success- 

 ful and indefatigable Scotch botanist and explorer who visited Cali- 

 fornia in 1832. 



4. Q. dumosa Nutt. Scrub Oak. Shrub 5 to 6 ft. high with 

 pale gray bark and tomentose branchlets; leaves coriaceous, broadly 

 or narrowly oblong, 1 in. long more or less, spinose-serrate and some- 

 times sinuate or irregularly incised; staminate aments 3 in. long; 

 acorns 2 together or solitary; nut oval, mostly pointed, J to IJ in. 

 long; cup hemispherical, strongly tuberculate at base, scales free 

 above with minute hairy tips. 



Common in the higher Coast Eanges south of San Francisco Bay. 

 One of the shrubs of the "chaparral." First collected by Nuttall 

 near r^anta Barbara. 



Var. bullata Engelm. Mostly 3 to 4 ft. high; leaves thicker, 

 rounder, spinescent, but often entire with strongly revolute margins; 

 nuts obtuse, cups shallower. — North Coast Range (Knoxville grade; 

 upper Conn Valley, Napa Kiver Basin, and elsewhere), rare south 

 of San Francisco Bay. 



5. Q. chrysolepis Liebmann. Maul Oak. Tree 30 to 40 ft. 

 high, or on exposed mountain summits a shrub 4 to 10 ft. high (in 

 such situations often gregarious); leaves oblong or narrowly-ovate to 

 elliptical, cordate to cuneate at base, acute or cuspidate at apex, 

 mostly entire on old trees, spinose-dentate on young ones or on 

 vigorous shoots, pale and glaucous above, fulvous-tomentose or gray- 

 pubescent below, at length glabrate; staminate aments 2 to 4 in. long, 

 the calyx with 4 to 7 ovate, acute lobes; acorn usually solitary; nut 

 oval or ovate, J to 2 in. long; cup shallow, the tubercles and scales 

 almost completely concealed by a close dense tomentum . 



High ridges and canon-walls of the Coast Ranges; Sierra Nevada. 

 Sometimes called "Gtold Leaf Oak," from the color of the tomentum 

 on the under surface of the leaves. First collected by Hartweg near 

 Monterey in 1846. 



6. Q. agrifolia Nee. Field Oak. Encina. Tree with very 

 broad low top, 20 to 40 ft. high; on exposed hilltops a small shrub a 

 few ft. high, with dark-brown bark; leaves oblong to oval or orbicu- 

 lar, entire or sinuate-dentate with spinose teeth, 2 to 2J in. long; 

 staminate aments with the calyx deep-red, at length fading; styles 3, 

 4 or 5; nut ovate, elongated, f to IJ in. long; cup turbinate, scales 

 thin and membranaceous. 



From Mendocino Co. southward; very common about San Fran- 

 cisco Bay. The trunk usually divides a few feet above the ground 

 into very wide-spreading branches, which at their extremities often 

 rest on the ground. Sargent says of this species, "The valleys and 

 low hills of the California coast owe their greatest charm to this oak 

 tree, which dotting their covering of vernal green or their brown 



