36 RHAMNACE®. (BUCKTHORN FAMILY.) 
tical, 1 to 4 inches long, denticulate or nearly entire; petals very small, broadly ovate, 
emarginate; fruit blackish-purple. 
2. CHANOTHUS, L. 
Calyx 5-cleft; the lobes acute; disk thick adhering to the tube and to the ovary; petals 
on long claws, hooded; stamens 5; filaments long-exserted; ovary 3-lobed; style short, 
3-cleft. The small flowers are in showy thyrsoid orcymose clusters, Species difficult. 
§ 2. Leaves 3-nerved. 
1. C. thyrsiflorus, Esch. (Ca.irornia Lizac.) Smooth, 6 to 15 ft. high; branches 
strongly angled; leaves rather thick, oblong to oblong-ovate, 1 to 14 inches long, usually 
smooth and shining above, canescent beneath; flowers bright blue in dense compoind 
racemes, terminating the long and ‘somewhat leafy peduncles. 
2. C. integerrimus, Hook & Arn. Slender, 2 or3 ft, high; branches round, usually 
warty; leaves thin, bright green, ovate to ovate-oblong, 1 to 3 inches long; thyrse large, 
white-flowered. ; 
3. C. dentatus, Torr & Gr. Low, not rigid; leaves small glandular-serrate, 
fascicled, the margin strongly undulate or revolute, somewhat resinous; flowers blue, in 
small roundish clusters. 
4. C. sorediatus, Hook & Arn. Rigid; inflorescence pubescent; leaves silky on 
the nerves, 4 to 14 inches long; flowers blue in shortly peduncled simple racemes 4 to 2 
inches long. 
5. C. divaricatus, Nutt. Grayish, usually spinose; leaves small, not tomentose 
beneath; flowers light blue or white, in nearly simple often elongated racemes, 1 to 4 
inches long; fruit resinous. 
6. C. incanus, Torr & Gr. Spinose; leaves hoary beneath with a very minute 
tomentum, cuneate to cordate at base; flowers in short racemes, white; fruit resinously 
warty. A straggling shrub along creeks. : 
§ 2. Leaves pinnately veined. 
7. ©. papillosus, Torr. & Gr. More or less hispidly villous or tomentose, 4 to 6 
ft. high; leaves glandular-serrulate, and the upper surface glandular-papillose, narrowly 
oblong, 1 to 2 inches long on slender petioles; flowers blue, in close clusters or short 
racemes, terminating slender naked peduncles; fruit not resinous. 
§ 3. Leaves small, often opposite, very thick, with numerous straight lateral veins; stipules 
mostly large and warty; flowers in sessile or shortly peduncled azillary clusters; fruit 
larger, with 3 horn-like or warty prominences below the summit. 
8 C. crassifolius, Torr. Erect 4 to 12 ft. high, the young branches white with a 
villous tomentum; leaves somewhat spinosely-toothed or rarely entire and revolutely 
margined; flowers lig’+ blue or white, in dense clusters. 
