Ceanothus cordulatus
Ceanothus confusus
mountain whitethorn, snow bush, whitethorn ceanothus
Rincon Ridge ceanothus
prostrate, spreading, or weakly ascending, often rooting at proximal nodes;
branchlets brown to reddish brown, ± rigid, glabrous or sparsely puberulent.
petiole 2–8 mm;
blade flat to cupped, ovate to elliptic, 10–30 × 6–18 mm, base rounded, margins usually entire, sometimes minutely glandular-denticulate distally, glands 18–30, apex obtuse, abaxial surface pale grayish green, sparsely puberulent or glabrous, sometimes villosulous along veins, adaxial surface pale green to grayish green, glaucous, dull, glabrate; 3-veined from base.
not fascicled, not crowded, shorter than internodes;
petiole 0–2 mm;
blade flat to ± cupped, elliptic to ± oblong or obovate, 10–20 × 5–14 mm, base obtuse to cuneate, margins thick or slightly revolute, slightly wavy, sharply dentate to spinose-dentate, teeth 3–9, apex acute or retuse, with an apical tooth, abaxial surface grayish green, strigillose on veins, adaxial surface green, dull, glabrous.
axillary, umbel-like or racemelike, sometimes densely clustered, 1.2–2(–4) cm.
axillary, 1.5–3 cm.
sepals, petals, and nectary usually white, rarely pink.
sepals, petals, and nectary blue, lavender, or purple.
3.5–5 mm wide, lobed;
valves rugose, viscid when young, weakly crested.
4–6 mm wide, lobed;
valves smooth, crested, horns subapical, prominent, erect, intermediate ridges weakly developed.
= 24.
= 24.
Ceanothus cordulatus
Ceanothus confusus
Ceanothus cordulatus is one of the most common shrubs in montane chaparral and forests of the Coast Ranges and Cascades of southern Oregon and northern California, southward through the Sierra Nevada, Transverse and Peninsular ranges of California, to the mountains of northern Baja California, and occurs disjunctly in the Charleston Mountains of Nevada.
Putative hybrids between Ceanothus cordulatus and C. velutinus var. velutinus, reported from the Klamath Mountains, the southern Cascade Range, and the Sierra Nevada, have been called C. ×lorenzenii (Jepson) McMinn. A rare intersectional hybrid between C. cordulatus and C. prostratus in the Lake Tahoe basin has been named C. ×serrulatus McMinn. Putative hybrids of C. cordulatus with C. diversifolius and C. integerrimus also have been reported (H. McMinn 1944).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Ceanothus confusus is weakly defined and perhaps best treated as a part of C. divergens (L. Abrams and R. S. Ferris 1923–1960, vol. 3). At least some populations in the Hood Mountains (Napa and Sonoma counties) include plants with the habit and leaf morphology of both species, while other, more uniform populations appear intermediate; it remains to be determined whether this pattern is a product of primary or secondary intergradation.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
