102 RHAMNACE^E. ' Ceanothus. 



5. CEANOTHUS, Linn. 



Calyx 5-cleft ; the lobes acute, connivent ; disk thick, adnate to the turbinate or 

 hemispherical tube and to the ovary. Petals on long claws, hooded. Stamens 5 ; 

 filaments filiform, long-exserted. Ovary 3-lobed : style short, 3-cleft. Drupe sub- 

 globose, 3-lobed, surrounded at base by the adnate calyx-tube, soon dry; the 3 

 crustaceous nutlets at length separating and dehiscing on the inner edge. Seed 

 obovate, convex on the back : cotyledons oval or obovate.' Shrubs or small trees, 

 sometimes spinescent ; with petioled leaves, and showy thyrsoid or cymose flowers. 

 Watson, Proc. Am. Acad. x. 333. 



Species 28, of which three are Mexican and four in the Atlantic States, the others belonging 

 to the region between the Rocky Mountains and the Pacific. 



1. Leaves all alternate, 3-nerved or pinnately veined, glandular-toothed or entire: 

 fruit not crested. CEANOTHUS proper. 



* Leaves three-nerved from the base. 



-t- Erect, the branches not rigidly divaricate nor spiny : inflorescence thyrsoid : leaves 

 usually large, glandular-serrulate (except in No. 3). 



1. C. thyrsiflorus, Eschscholtz. A tall shrub or small tree, 6 to 15 feet high, 

 nearly glabrous ; branches strongly angled : leaves rather thick, oblong to oblong- 

 ovate, 1 to 1| inches long, usually smooth and shining above, canescent beneath : 

 flowers bright blue, in dense compound racemes, terminating the usually elon- 

 gated and somewhat leafy peduncles. Lindl. Bot. Eeg. xxx, t. 38 ; Nutt. Sylva, 

 ii. 44, t. 57. 



In the Coast Ranges from Monterey to Humboldt County. Known as "California Lilac" and 

 often cultivated. 



2. C. velutinus, Dougl. A stout diffusely branching shrub, 2 or 3 feet high, 

 usually glabrous : leaves thick, broadly ovate or elliptical, 1^ to 3 inches long, resi- 

 nous and shining above, sometimes velvety beneath ; petioles stout, half an inch 

 long: flowers white, in a loose thyrse: peduncles usually short. Hook. Fl. i. 125, 

 t. 45, & Bot. Mag. t. 5165. 



From Northern California to the Columbia, and very frequent eastward to Colorado. 



3. C. integerrixnus, Hook. & Arn. A more slenderly branched shrub, 2 to 6 

 feet high, glabrous or soon becoming so, rarely pubescent ; branches terete, usually 

 warty : leaves thin, bright green, ovate to ovate-oblong, 1 to 3 inches long, entire 

 or very rarely slightly glandular-serrulate, on slender petioles 2 to 6 lines long : 

 thyrse often large and open, terminating the slender branches or axillary and rather 

 shortly peduncled, mostly white-flowered. Bot. Beechey, 329. C. Californicus, 

 Kellogg, Proc. Calif. Acad. ii. 55. C. Nevadensis, Kellogg, 1. c. ii. 152, fig. 45. 



Var. (?) parvifolius, Watson. Of very slender habit, wholly glabrous : leaves 

 much smaller, about half an inch long, shortly petioled : flowers light blue, in 

 rather short simple racemes. Proc. Am. Acad. x. 334. 



Frequent in the mountains from Central California to the Columbia. The variety, seeming 

 to run into the typical form, is confined to the Sierra Nevada, from Yosemite Valley northward. 



-*- -t- Low, the branches not rigidly divaricate nor spiny : flowers blue, in short simple 

 racemes or pedunculate clusters : leaves small, glandular-serrate. 



4. C. dentatus, Torr. & Gray. Erect, hirsutely pubescent or rarely nearly gla- 

 brous : leaves ^ to 1 inch long, usually small and fascicled, obovate to oblong-elliptic 

 or lanceolate, acute at both ends or obtuse at the apex, the margin becoming strongly 

 undulate or revolute ; the smaller leaves apparently pinnate-veined and often more 

 or less resinous : flowers in small roundish clusters, on naked terminal peduncles 



