BUCKTHORN FAMILY. 253 



Leaves similar, pinnately veined, but the margins revolute, seemingly entire, and 



sometimes concealing the supplementary lateral nerves 4. C. parryi. 



Flowers blue, the clusters in a simple raceme mostly / 2 to 1 in. long; leaves mostly 

 rather small, usually not 3-nerved. 

 Leaves subcoriaceous, with smooth waxy surface, the margin very glandular- 

 serrate 5. C. foliosus. 



Leaves papillate near the revolute margin 6. C. dentatus. 



Leaves similar, but glandular-papillate on the entire upper surface 



7. C. papillosus. 

 Brandies more or less rigid and spinescent. 



Leaves glandular-denticulate; flowers deep or very light blue, in a simple raceme; 



branchlets stiff 8. C. sorediatus. 



Leaves entire: flowers white, in a simple or paniculately compound raceme; branch- 

 lets thick and stout, spur-like, very glaucous; fruit warty-roughened; leaves 



strongly 3-nerved 9. C. incanus. 



B. Leaves opposite. 

 Fruit with conspicuous dorsal horns; stipule-bases warty or cork-like and persistent; 

 flowers in simple umbels. 

 Erect shrubs. 



Flowers white; leaves entire 10. C. cuneatus. 



Flowers blue; leaves finely spinose-dentate on the upper half 11. C. rigidus. 



Flowers blue (or white) ; leaves rather coarsely spinose-dentate. 



Branchlets gray; pedicels 2 lines long 12. C. jepsonii. 



Branchlets reddish or brownish; pedicels 5 to 7 lines long 13. C. purpurea. 



Low-spreading shrub; flowers blue; leaves coarsely few-toothed toward the apex 



14. C. prostratus. 



1. C. velutinus Dougl. Large shrub 8 to 12 ft. high, the branches mostly 

 ascending; odor very sweet and heavy; leaves elliptic or ovatish, rounded or 

 subcordate at base, finely glandular-serrate, pale and strongly 3-nerved beneath, 

 varnished above and frequently of a rich chocolate-brown, \y 2 to 3 in. long, 

 on petioles y 2 in. long or less; panicle 2 to 3 in. high; flowers white, 2 lines 

 broad; capsules smooth, lobed at top, nearly crestless, sticky-glandular. 



Mt. Shasta ; Modoc Co. ; and the northern Sierra Nevada. Often called 

 Snow Brush. Yar. laevigatus T. & G. Subarborescent ; leaves glabrous, light 

 green; inflorescence more ample; fruit somewhat crested. — Mt. Tamalpais, Mt. 

 St. Helena and northward in the Coast Eanges to Mendocino and Humboldt cos. 



2. C. integerrimus H. & A. Deer-brush. Tall shrub, 10 to 15 ft. high; 

 twigs green or at length purplish, subangular when young; leaves deep green 

 above, paler beneath, oblong-elliptic, obtuse, mostly acute at base, entire, % 

 to 1 in. long; inflorescence simple and about 2 in. long, or compound and 

 about 4 in. long, or in fruit twice as long, equaled by the leafy (or often 

 nearly leafless) peduncles; flowers white (sometimes blue or pink); capsules 

 nearly globose, lobed, smooth, crestless. — (C. californicus Kell.) 



Common in the Yellow Pine belt of the Sierra Nevada or immediately 

 below it. Found in the Santa Cruz Mts., Mayacamas Eange and frequent 

 northward to Mt. Shasta. June-July. Favors good soils. 



3. C. thyrsiflorus Esch. Blue Blossom. Shrub 5 to 8 ft. high or becom- 

 ing a small ungainly or pole-like tree up to 15 to 25 ft. high; leaves green 

 on both surfaces, elliptical or oblong-ovate, strongly 3-nerved beneath, the 



margin mucronate-serrate or serrulate with somewhat impressed teeth, 1 to 2 

 in. long, 6 to 10 lines broad; inflorescence a panicle of somewhat corymbose 

 racemes, iy 2 to 234 in. long, mostly long-peduncled, with leaves subtending 

 1 or 2 of the lower racemes; bractlets ovate, acuminate, 2y 2 lines long; flowers 

 blue or sometimes varying to white; capsules globose, black, smooth, little 

 lobed, 2 lines in diameter. 



Abundant near the coast, following strictly the Eedwood belt: Santa Lucia 

 Mts.; Monterey; Santa Cruz Mts.; San Francisco; Marin Co. to Del Norte 

 Co., thence north to Washington. Sometimes forming flat mats on ocean bluffs. 



