BUCKTHORN FAMILY 73 



strigose above, pale green or slightly canescent beneath, appressed villous-pubescent on the veins, 

 sparsely strigose between ; peduncles 1-3 cm. long ; racemes simple or compound, 2-5 cm. long ;' 

 flowers light blue ; capsule 4 mm. broad, shallowly lobed, crested, otherwise smooth and resinous! 

 Mountain slopes, Upper Sonoran and Transition Zones; California Coast Ranges from Humboldt County 

 south to Los Angeles County. Type locality: California. Collected by Douglas. March-April. 



22. Ceanothus leucodermis Greene. Chaparral Whitethorn. Fig. 3132. 



Ceanothus leucodermis Greene, Kew Bull. 1895: 15. 1895. 



Ceanothus divaricatus war. egiandiilosus Torr. Pacif. R. Rep. 4: 75. 18-57. 



Rigidly branched shrub, 2-3 m. high, the bark smooth pale green, branchlets divaricately 

 spreading, short and spinescent, glabrous or nearly so. Leaves elliptic to ovate, 10-20 mm. long, 

 serrulate or usually entire, plane and firm-coriaceous, dull and rather light green above, gray- 

 green beneath, nearly or quite glabrous ; panicles simple or with a few branches, 3-8 cm. long ; 

 flowers white or very pale blue ; capsules 4 mm. broad, scarcely lobed and the crests obscure, the 

 surface covered with a saponaceous resin. 



Chaparral belt of the foothills and lower mountain slopes, Upper Sonoran Zone; Inner Coast Ranges of 

 Alameda County and southern Sierra Nevada, Tulare County, to cismontane southern California and northern 

 Lower California. Type locality: Santa Barbara. March-April. 



23. Ceanothus cordulatus Kell. Mountain Whitethorn. Fig. 3133. 



Ceanothus cordulatus Kell. Proc. Calif. Acad. 2: 124. pi. 39. 1861. 



Low spreading shrub, intricately branched, 1-2 m. high with smooth whitish bark, the ulti- 

 mate branches rigid, divaricate and spinescent, very glaucous, the young sparsely short-pubescent 

 but soon smooth. Leaves alternate, elliptic-ovate to orbicular-ovate, 1-2 cm. long, entire or rarely 

 with a few teeth, plane, light green above and glabrous or sparsely strigose, pale beneath and 

 sparsely strigose, distinctly 3-nerved ; flowers in simple panicles or sometimes in racemes, white ; 

 capsules deeply lobed and prominently crested with a dorsal ridge, otherwise nearly smooth. 



Dry mountain slopes and open pine forests. Arid Transition and Canadian Zones; Cascade Mountains, and 

 Douglas and Curry Counties, Oregon, south to Lower California and east to western Nevada. Type locality: 

 near Washoe, Nevada. June-Aug. 



24. Ceanothus incanus Torr. & Gray. Coast Whitethorn. Fig. 3134. 



Ceanothus incanus Torr. & Gray, Fl. N. Amer. 1 : 266. 1838. 



Widely branched shrub, 1-3 m. high, with smooth whitish bark, the branchlets smooth and 

 glaucous, the ultimate ones short, divaricate, spinose or stout and blunt. Leaves alternate, ellip- 

 tic-ovate to orbicular-ovate, 1 . 5-5 cm. long, entire or rarely serrulate, plane and firm, glabrous 

 and green above, beneath strongly 3-nerved, strigose at least on the nerves, and canescent with 

 a fine close indument between ; panicles usually compound, 2-5 cm. long, the rachis and short 

 peduncles tomentose; flowers white; capsule 4.5 mm. broad, the e.xocarp thick and rugosely 

 roughened. 



Canyons and mountain slopes, mainly Humid Transition Zone; California Coast Ranges from Humboldt 

 County to Monterey County. Type locality: California. Collected by Douglas. April-May. 



25. Ceanothus megacarpus Nutt. Big-podded Ceanothus. Fig. 3135. 



Ceanothus macrocarpus Nutt. in Torr. & Gray, Fl. N. Amer. 1: 267. 1838. Not Cav. 1794. 



Ceanothus megacarpus Nutt. N. Amer. Sylva 2: 46. 1846. 



Ceanothus cuneatus var. macrocarpus K. Brandg. Proc. Calif. Acad. II. 4:205. 1894. 



Erect rather compact shrub, 2—3 m. high, the young twigs appressed-pubescent, becoming 

 glabrous and reddish or gray-brown. Leaves alternate, 1-2 cm. long, spatulate to obovate, obtuse 

 to rounded or emarginate at apex, cuneate at base, rather thick and firm, dull green and glabrous 

 above, minutely canescent beneath, the margins slightly revolute, entire or rarely sparsely denticu- 

 late ; flowers white ; capsule 8-12 mm. broad, scarcely lobed, laterally horned, the apical crests low. 



Mountain canyons, Upper Sonoran Zone; Coast Ranges of southern California from Santa Barbara County 

 to northern San Diego County. Type locality: hills near Santa Barbara. March-April. 



26. Ceanothus insularis Eastvv^. Island Ceanothus. Fig. 3136. 



Ceanothus insularis Eastw. Proc. Calif. Acad. IV. 16: 362. 1927. 



Erect shrub with stifif rather compact branches, young twigs tomentulose. Leaves alternate 

 or opposite, elliptic to cuneate-obovate, truncate or often retuse at apex, entire, 12-20 mm. long, 

 green and glabrous above, minutely canescent beneath; flowers in small umbel-like clusters, 

 white or with bluish centers ; capsule globose, 8-10 mm. in diameter, without horns or crests or 

 with minute subapical or lateral horns. 



Canyon slopes. Upper Sonoran Zone; Santa Rosa, Santa Cruz, and Santa Catalina Islands, southern Cali- 

 fornia. Type locality: Santa Cruz Island. Jan.-March. 



27. Ceanothus verrucosus Nutt. Warty-stemmed Ceanothus or Barranca-brush. 



Fig. 3137. 



Ceandhus verrucosus Nutt. in Torr. & Gray, Fl. N. Amer. 1:267. 1838. 



Erect compactly branched shrub, the young twigs tomentulose, becoming dark grayish brown. 



