BUCKTHORN FAMILY 473 



ger Canon, Eamona, Jepson 8509. C. cyaneus Eastw. Proe. Cal. Acad. ser. 4, 16:361 (1927), 

 type loc. Lakeside, San Diego Co., M. Phillbrooh. 



18. C. sorediatus H. & A. Jim Brush. Erect shrub 4 to 7 (or 14) feet high 

 with rigid divaricate branchlets; branchlets sparingly villous, at length olive- 

 color or purplish; leaf -blades ovate or elliptic-ovate, green above, paler or whitish 

 and slightly pubescent beneath, glandular-denticulate, 3-nerved, 5 to 10 lines (or 

 to 1% inches) long, on petioles a line or two long; panicles simple, terminal or sub- 

 terminal, 1 or 2 (to 6) on each branchlet, ovate or broadly oblong, 1/2 to 1^4 inches 

 long; flowers blue or almost white; capsules lobed, crested, 2 to 2% lines broad. 



Caiion sides, 300 to 2500 feet : Coast Ranges from Humboldt and Solano Cos. 

 to Monterey Co. ; Santa Inez Mts. to the Santa Ana Mts. Apr.-May. 



Geog. note. — In chaparral of the hill country Ceanothus sorediatus often forms marked 

 colonies on north slopes. If the fire interval is sufficiently long, tall individuals may develop. In 

 Claremont Canon, Berkeley Hills, a slender tree 16 feet high was measured in 1917; its trunk 

 (51/^ feet high to the forks) was IVz feet in circumference at 1% feet. On the other hand, in 

 openly wooded gentle hill country, as in the Santa Margarita Hills, the individuals, spaced like 

 Blue Oaks, may develop rounded cro^vns which in April are great balls of flowers resting on the 

 ground. Ceanothus sorediatus does not, as a rule, crown-sprout, so that in consequence chaparral 

 fires are extremely destructive to stands of this species. It is most abundant in the inner Coast 

 Eanges from Solano Co. to San Luis Obispo Co. and is often the only species of the Euceanothi 

 where it occurs. South of San Luis Obispo Co. it overlaps Ceanothus oliganthus, but it occurs 

 only at scattered stations near the coast. Ceanothus oliganthus, in its entirety, is distinguishable 

 from C. sorediatus only by pubescence. C. sorediatus simulates C. tomentosus var. olivaceus very 

 closely in aspect and in shape of the leaf and hue of the under surface, but the former has larger 

 flowers, its racemes are generally more compact and almost always borne on short peduncles or 

 borne subsessile. 



Locs. — Coast Eanges : Kneeland Prairie, Humboldt Co., Tracy 4902 ; Bull Creek, Humboldt 

 Co., Tracy 6676; Wilder Eange, s. Humboldt Co., Tracy 4986; Weldon Canon, Vaca Mts., Jepson 

 2453; Tranches Creek, Napa Eange, Jepson 14,002; Caux's Knob, w. of St. Helena, Jepson 

 14,005 ; Mt. Tamalpais, Jepson 13,998 ; Oakland Hills, Jepson 6814 ; Las Trampas Eidge, Jepson; 

 Donner Canon, Mt. Diablo, Jepson 7586 ; Mt. Hamilton, Jepson 4200 ; Palo Alto, C. F. BaTcer 516 ; 

 Guadalupe Mine, Santa Clara Co., Jepson 9095; Santa Lucia Creek, Santa Lucia Mts., Jepson; 

 Santa Margarita, Jepson 11,965a ; Arroyo Grande, Summers 138. S. Cal. : Santa Inez Mts., Hall 

 7849 ; Seminole Hot Sprs., Santa Monica Mts., Peirson 7116 ; Silverado Caiion, Santa Ana Mts., 

 Peirson. 



Eefs.— Ceanothus sorediatus H. & A. Bot. Beech. 328 (1840), type from Cal., Douglas; 

 Jepson, Fl. W. Mid. Cal. 257 (1901), ed. 2, 254 (1911), Man. 621 (1925). C. intricatus Parry, 

 Proc. Davenp. Acad. 5:169 (1889), type loc. Mt. Tam.alpais summit, Curran. 



19. C. oliganthus Nutt. Explorers Bush. Shrub, often with tree-like trunk, 

 4 to 9 feet high ; branchlets densely short-hispid or villous, sometimes glabrescent, 

 sub-flexible; leaf -blades ovate, obtuse or sub-acute, rounded at base or subcordate, 

 denticulate, the teeth mostly glandular, 1/2 to 1% inches long, thinly or scantily 

 pubescent above, drying brown or blackish, beneath pale green or chestnut brown 

 and pubescent or hirsute, especially along the veins; panicles mostly simple, broad, 

 more or less open, % to 11/2 inches long; flowers deep blue or purplish; capsules 

 roughly resinous, rather strongly crested, slightly depressed, 2 to 2^2 lines broad. 



Dry hills, 500 to 4500 feet : near the coast from San Luis Obispo Co. to the San 

 Gabriel Mts. May-June. 



Locs. — Santa Margarita Hills, Summers; Santa Barbara, Brewer 298; Ojai Valley, Huliy; 

 Santa Susanna Mts., Brewer 214; Mt. Wilson, Peirson 113. The following variety is of doubtful 

 importance. 



Var. orcuttii Jepson. Flowers paler blue; capsules strongly rugose and loosely villous. — 

 Mountains of San Diego Co., 1500 to 5000 feet: Palomar Mt., Peirson 6711; Julian, Purpus. 



Eefs.— Ceanothus oliganthus Nutt.; T. & G. Fl. 1:266 (1838), type loc. Santa Barbara, 

 Ntittall; Jepson, Man. 621 (1925). C. hirsutus Nutt. I.e., type loc. Santa Barbara, Nuttall. 

 C. divaricatus Nutt. I.e., type loc. Santa Barbara, Nuttall. Var. orcuttii Jepson (by error 

 "Trel."), Man. 621 (1925). C. orcuttii Parry, Proe. Davenp. Acad. 5:194 (1889), type loc. "high 

 mts. east of San Diego", Orcutt. C. hirsutus var. orcuttii Trel.; Gray, Syn. Fl. r:414 (1897). 



20. C. cordulatus Kell. Snow-brush. (Fig. 234.) Low widely-spreading 

 thorny shrub (1 to 4 feet high and 8 to 9 feet across), rigidly and intricately 



