Ceanothus cordulatus

Kellogg

Proc. Calif. Acad. Sci. 2: 124, fig. 39. 1863.

Common names: Mountain whitethorn
Illustrated
Treatment appears in FNA Volume 12. Treatment on page 87. Mentioned on page 79, 84, 104.

Shrubs, evergreen, 0.5–1.5 m. Stems ascending to spreading, not rooting at nodes; branchlets yellowish or grayish green, glaucescent, thorn-tipped, round in cross-section, rigid, puberulent, glabrescent. Leaves: 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. Inflorescences axillary, umbellike or racemelike, sometimes densely clustered, 1.2–2 (–4) cm. Flowers: sepals, petals, and nectary usually white, rarely pink. Capsules 3.5–5 mm wide, lobed; valves rugose, viscid when young, weakly crested. 2n = 24.


Phenology: Flowering May–Jul.
Habitat: Rocky ridges and slopes, chaparral, conifer and mixed evergreen forests.
Elevation: 400–3400 m.

Distribution

V12 781-distribution-map.jpg

Calif., Nev., Oreg., Mexico (Baja California)

Discussion

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).

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

... more about "Ceanothus cordulatus"
pale grayish green +
villosulous +, glabrous +  and puberulent +
pale green +  and grayish green +
glabrate +  and glaucous +
perigynous +  and epigynous +
Clifford L. Schmidt† +  and Dieter H. Wilken +
Kellogg +
rounded +
3-veined +  and veined +
not gland-dotted +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
3[-5]-veined +  and pinnate +
spinulose +, spinose +, serrate +  and entire +
denticulate +, dentate +, crenulate +, crenate +  and serrulate +
ovate;elliptic +
6mm;18mm +
glaucescent +
glabrescent +  and puberulent +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Mountain whitethorn +
Calif. +, Nev. +, Oreg. +  and Mexico (Baja California) +
400–3400 m. +
Rocky ridges and slopes, chaparral, conifer and mixed evergreen forests. +
free +  and adnate +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
unisexual +  and bisexual +
racemelike +  and umbel-like +
1.2 cm12 mm <br />0.012 m <br /> (2 cm20 mm <br />0.02 m <br />) +
deciduous +  and persistent +
glandular-denticulate +
intrastaminal +
superior +  and inferior +
not fleshy +
perigynous +  and epigynous +
adnate +  and distinct +
6 +  and 5 +
Clawed (?) +, Obovate (?) +  and Spatulate (?) +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Flowering May–Jul. +
2-4-carpellate +
Proc. Calif. Acad. Sci. +
pink +, usually white +  and cream blue or purple +
distinct +
spreading +  and incurved +
6 +  and 5 +
keeled;lanceolate;deltate +
Illustrated +
not rooting +
ascending +  and spreading +
3-veined +  and veined +
Ceanothus cordulatus +
Ceanothus subg. Ceanothus +
species +
paniclelike +  and racemelike +
gland-tipped +
crested +
unarmed +  and armed +
polygamous +, dioecious +  and synoecious +