BUCKTHORN FAMILY 479 



Pine woods, especially on ridges, 3000 to 7000 feet : Sierra Nevada from Mari- 

 posa Co. to Shasta Co.; Lake Co. to Siskiyou Co. North to Washington, east to 

 Nevada. Apr.-May. 



Geog. note. — Ceanothus prostratus colonizes extensive areas in the pine woods throughout 

 the northern Sierra Nevada. In the southern Sierra Nevada from Madera Co. to Tulare Co. it 

 is perhaps absent though it has been vaguely reported from Mineral King. In this region it is 

 in the main or wholly replaced by C. diversifolius Kell. 



Locs. — Sierra Nevada: Panoche Peak, Mariposa Co., ace. J. Grinnell; Yankee HiU, Colum- 

 bia, A. L. Grant 653; Wiley, Amador Co., Hansen 59; Forest Hill, Placer Co., Bolander 4557; 

 Lake Tahoe, C. F. Allen; Donner Lake, Lemmon; Sierraville, Jepson 8057a; Nevada City, Mich- 

 ener; betw. Meadow Valley and Eich Pt., Plumas Co., Jepson; Lassen Peak, Chesnut 4- Drew; 

 Gold Eun Creek, Susanville, Jepson; Fandango Pass, "Warner Mts., Jepson; Sugar Hill, Davis 

 Creek, Modoc Co., Jepson; Forestdale, sw. Modoc Co., If. S. BaTcer ; Whitmore, Shasta Co., Jep- 

 son; upper Fall Eiver Valley, ne. Shasta Co., Jepson; Goosenest Mt., e. Siskiyou Co., Butler 903. 

 Coast Eanges: Upton, near Sisson, Jepson 14,021; Quartz Valley, w. Siskiyou Co., Butler 410. 



Var. profugus Jepson var. n. Prostrate shrub 3 to 7 feet wide ; leaf -blades 2 to 3 lines long, 

 cuneatish-oblong, 3-toothed at apex, the lateral teeth minute, cuspidate, the middle one larger, 

 mostly rounded and not cuspidate. — (Frutex prostratus, ped. 3-7 latus; folia lin. 2-3 longa, 

 subcuneato-oblongata, apice 3-dentata, dentibus lateralibus minutis, cuspidatis, dente mediano 

 majore, obtuso non cuspidato.) — Little Eed Mt., northern Mendocino Co., in an open forest of 

 Pinus ponderosa and P. lambertiana {Jepson 16,505, type). 



Var. divergens K. Bdg. Low scrambling shrub, the branches horizontally spreading or 

 trailing ; leaf -blades strongly dentate-spinose ; horns of capsule more lateral. — Mountain slopes, 

 2000 to 4000 feet: Coast Eanges from Lake Co. to eastern Sonoma Co. 



Locs. — Mt. Konocti, Jepson; Cobb Mt., Jepson 14,039; Mt. St. Helena, Jepson 14,036; Ee- 

 becca ranch, sw. of Calistoga, Jepson 14,037; Hoods Peak, Michener 4' Bioletti. 



Var. grandifolius Jepson. Leaf -blades % to 1^ inches long. — Coastal: Pt. Eeyes peninsula 

 to Sonoma Co. 



Eefs. — Ceanothus prostratus Benth. PI. Hartw. 302 (1848), type loc. "in montibus Sacra- 

 mento", Hartweg 284, that is, northern Sierra Nevada about opposite Chico (cf. Erythea 5:55) ; 

 Jepson, Fl. W. Mid. Cal. 258 (1901), ed. 2, 255 (1911), Man. 624 (1925). C. prostratus var. 

 laxus Jepson, Man. 624 (1925), type loc. Hot Springs Valley, Lassen Peak, Jepson 4099, a 

 looser form with obovate dentate leaf -blades. Var. profugus Jepson. Var. divergens K, Bdg. 

 Proc. Cal. Acad. ser. 2, 4:210 (1894); Jepson, Man. 624 (1925). C. divergens Parry, Proc. 

 Davenp. Acad. 5:173 (1889), type loc. near Calistoga, Parry. Var. grandifolius Jepson, I.e. 

 C. rigidus var. grandifolius Torr. Pac. E. Eep. 4:75 (1857), type loc. Pt. Eeyes, Bigelow. C. 

 verrucosus var. grandifolius K. Bdg. Proc. Cal. Acad. ser. 2, 4:207 (1894). 



30. C. fresnensis Dudley, Fresno Mat. Procumbent or semi-prostrate, 

 forming circular mats 7 to 10 feet across, the stems thick; leaf -blades narrow-ob- 

 ovate, more or less toothed at the truncatish apex, thinly woolly above, below with 

 a minute quilted felt, 2 to 4 (or 5) lines long; flowers blue; capsules 2 lines long; 

 horns slender. 



Mountain ridges, 4500 to 6800 feet : Tuolumne Co. to Fresno Co. May. 



Field note. — Ceanothus fresnensis has been little studied but as a species it seems deficient 

 in technical character. Its habit is, however, so pronounced that as a result of field studies we 

 here describe it as a natural unit. It would appear that only a few individuals have been ob- 

 served in a locality and the known localities in the Yellow Pine belt, which are very few, have 

 all been discovered in the region between the Stanislaus Eiver and the North Fork Kings Eiver. 

 It is therefore a well localized form. It grows at a higher altitude than Ceanothus cuneatus and 

 is often an associate of C. cordulatus. 



Locs. — Confidence, Tuolumne Co. (Bot. Gaz. 53:68); near Mariposa Big Trees, ace. Hop- 

 ping; Fresno Big Trees, Jepson 15,987; Big Creek, Fresno Co., Hopping. Shrubs at French 

 Mdws. (L. S. Smith 2631) and Onion Creek (L. S. Smith 2632), Placer Co., may possibly be re- 

 ferred here when better known. 



Eefs. — Ceanothus fresnensis Dudley; Abrams, Bot. Gaz. 53:68 (1912), type loc. Mt. 

 Stevenson, Pine Eidge, Fresno Co., Hall 4- Chandler 407. C. rigidus var. fresnensis Jepson, Man. 

 623 (1925). 



31. C. crassifolius Torr. White-back Ceanothus. Much-branched shrub 3 

 to 11 feet high; leaf -blades thick and coriaceous, elliptic, I/2 to II/2 inches long, 

 shortly petioled, dentate with the margin strongly infolded between the small 

 teeth, or the teeth quite concealed by the strongly revolute edge, rarely entire, the 

 upper surface light green, minutely roughened, the lower surface densely white- 



