Ceanothus cordulatus
Ceanothus perplexans
mountain whitethorn, snow bush, whitethorn ceanothus
cupped leaf ceanothus, desert ceanothus
ascending to spreading, not rooting at nodes;
branchlets yellowish or grayish green, glaucescent, thorn-tipped, round in cross section, rigid, puberulent, glabrescent.
erect, not rooting at nodes;
branchlets brown to grayish brown, rigid, glabrate or tomentulose, glabrescent.
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;
petiole 1–3 mm;
blade flat to ± cupped, elliptic, widely obovate, or suborbiculate, 10–20 × 7–18 mm, base rounded, margins thick, not revolute, usually sharply denticulate, sometimes weakly denticulate to almost entire, teeth 7–15, apex rounded to ± truncate, abaxial surface pale green to yellowish green, puberulent, hairs curly, glabrescent, adaxial surface green to yellowish green, sparsely puberulent, hairs curly, glabrescent.
axillary, umbel-like or racemelike, sometimes densely clustered, 1.2–2(–4) cm.
axillary, 0.7–2 cm.
sepals, petals, and nectary usually white, rarely pink.
sepals and petals white to cream;
nectary yellow to green.
3.5–5 mm wide, lobed;
valves rugose, viscid when young, weakly crested.
4–6 mm wide, usually not, sometimes weakly, lobed;
valves smooth, horns lateral, usually minute, sometimes absent, spreading, intermediate ridges absent.
= 24.
= 24.
Ceanothus cordulatus
Ceanothus perplexans
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 perplexans occurs in southwestern Arizona, on the desert slopes of the San Bernardino Mountains and Peninsular Ranges of southern California, and in Baja California. Ceanothus specimens from Guadalupe Island, Baja California, with entire or weakly denticulate leaf margins have been referred to either C. crassifolius or C. cuneatus, but in their leaf shape and indumentum they more closely resemble C. perplexans.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
