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mountain whitethorn, snow bush, whitethorn ceanothus

céanothe á feuilles étroites, inland Jersey tea, Jersey tea, New Jersey tea, prairie redroot

Habit 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. Shrubs, deciduous, 0.6–1 m. Stems erect to ascending, not rooting at nodes; branchlets green, brown, or reddish, not thorn-tipped, round in cross section, flexible, ± appressed-puberulent or villosulous, 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.

petiole 2–6(–10) mm;

blade not aromatic, flat, usually elliptic to lanceolate, sometimes ovate or oblanceolate, (20–)25–70 × 10–30 mm, herbaceous, not resinous, base cuneate to rounded, margins serrate to serrulate, teeth (37–)45–71, apex acute to obtuse, abaxial surface pale green, glabrous or puberulent, especially on veins, adaxial surface dark green, dull, villosulous or glabrate; 3-veined from base.

Inflorescences

axillary, umbel-like or racemelike, sometimes densely clustered, 1.2–2(–4) cm.

terminal, umbel-like, globose to hemispheric, 4–8 cm.

Flowers

sepals, petals, and nectary usually white, rarely pink.

sepals, petals, and nectary white.

Capsules

3.5–5 mm wide, lobed;

valves rugose, viscid when young, weakly crested.

3–5 mm wide, lobed;

valves smooth, usually not crested, sometimes weakly crested near apex.

2n

= 24.

Ceanothus cordulatus

Ceanothus herbaceus

Phenology Flowering May–Jul. Flowering Mar–Aug.
Habitat Rocky ridges and slopes, chaparral, conifer and mixed evergreen forests. Open rocky areas or on sandy soils, slopes and bluffs in shrublands, prairies, forests.
Elevation 400–3400 m. (1300–11200 ft.) 10–1800 m. (0–5900 ft.)
Distribution
from FNA
CA; NV; OR; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; CO; IA; IL; IN; KS; KY; LA; MA; MI; MN; MO; MT; ND; NE; NH; NM; NY; OH; OK; SD; TN; TX; VA; VT; WI; WY; MB; ON; QC; Mexico (Coahuila)
[WildflowerSearch map]
[BONAP county map]
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).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Ceanothus herbaceus is an older name than C. ovatus, which has been used widely in botanical and horticultural literature (G. K. Brizicky 1964c). Plants with persistently puberulent leaves occur principally east of the Mississippi River Valley and have been called var. pubescens, but the extent of intergradation occurs over a broad geographic area and deserves further study (N. C. Coile 1988). Putative hybrids between C. herbaceus and C. fendleri in the eastern foothills of the Rocky Mountains were named C. ×subsericeus Rydberg.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 87. FNA vol. 12, p. 82.
Parent taxa Rhamnaceae > Ceanothus > subg. Ceanothus Rhamnaceae > Ceanothus > subg. Ceanothus
Sibling taxa
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. crassifolius, C. cuneatus, C. cyaneus, C. dentatus, C. divergens, C. diversifolius, C. fendleri, C. ferrisiae, C. foliosus, C. fresnensis, C. gloriosus, C. griseus, C. hearstiorum, C. herbaceus, C. impressus, C. incanus, C. integerrimus, C. jepsonii, C. lemmonii, C. leucodermis, C. maritimus, C. martini, C. masonii, C. megacarpus, C. microphyllus, C. oliganthus, C. ophiochilus, C. otayensis, C. palmeri, C. papillosus, C. parryi, C. parvifolius, C. pauciflorus, C. perplexans, C. pinetorum, C. prostratus, C. pumilus, C. purpureus, C. roderickii, C. sanguineus, C. sonomensis, C. spinosus, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. cordulatus, C. crassifolius, C. cuneatus, C. cyaneus, C. dentatus, C. divergens, C. diversifolius, C. fendleri, C. ferrisiae, C. foliosus, C. fresnensis, C. gloriosus, C. griseus, C. hearstiorum, C. impressus, C. incanus, C. integerrimus, C. jepsonii, C. lemmonii, C. leucodermis, C. maritimus, C. martini, C. masonii, C. megacarpus, C. microphyllus, C. oliganthus, C. ophiochilus, C. otayensis, C. palmeri, C. papillosus, C. parryi, C. parvifolius, C. pauciflorus, C. perplexans, C. pinetorum, C. prostratus, C. pumilus, C. purpureus, C. roderickii, C. sanguineus, C. sonomensis, C. spinosus, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
Synonyms C. herbaceus var. pubescens, C. ovatus, C. ovatus var. pubescens
Name authority Kellogg: Proc. Calif. Acad. Sci. 2: 124, fig. 39. (1863) Rafinesque: Med. Repos., hexade 2, 5: 360. (1808)
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