Ceanothus thyrsiflorus

Eschscholtz

Mém. Acad. Imp. Sci. St. Pétersbourg Hist. Acad. 10: 285. 1826.

Common names: Blueblossom
Synonyms: Ceanothus thyrsiflorus var. chandleri Jepson C. thyrsiflorus var. repens McMinn
Treatment appears in FNA Volume 12. Treatment on page 90. Mentioned on page 81, 84, 86, 87, 89, 91, 92, 93.

Shrubs, sometimes arborescent, evergreen, 0.5–6 m. Stems erect, usually ascending to arcuate, rarely prostrate, not rooting at nodes; branchlets green, not thorn-tipped, angled in cross-section, flexible, not tuberculate, sparsely puberulent or glabrous. Leaves: petiole 3–10 mm; blade flat to cupped, elliptic to ovate, 10–40 (–50) × 5–15 (–20) mm, base obtuse to rounded, margins denticulate to serrulate, usually not revolute, sometimes incompletely revolute, teeth glandular, 23–48, apex obtuse, abaxial surface pale green, sparsely puberulent to villosulous or glabrate, veins prominently raised, puberulent to villosulous, adaxial surface dark green, glabrate; 3-veined from base. Inflorescences terminal, usually racemelike, rarely paniclelike, 2.5–9 cm. Flowers: sepals, petals, and nectary usually pale to deep blue, rarely white. Capsules 3–4 mm wide, weakly lobed; valves smooth, viscid, not crested. 2n = 24.


Phenology: Flowering Mar–Jun.
Habitat: Sandy or rocky flats and slopes, maritime chaparral, open sites in mixed evergreen and conifer forests.
Elevation: 10–600 m.

Distribution

V12 329-distribution-map.jpg

Calif., Oreg., Mexico (Baja California)

Discussion

Ceanothus thyrsiflorus occurs along the coast from Coos County, Oregon, south to Santa Barbara County, California, and disjunctly near Eréndira, Baja California. A wide range of growth forms characterize this species and the closely related C. griseus, including plants ranging from almost prostrate to arborescent, sometimes with single trunks. Prostrate plants from several maritime bluffs along the California coast have been called C. thyrsiflorus var. repens McMinn; they retain their stature under cultivation. Named hybrids include C. ×regius (Jepson) McMinn (C. thyrsiflorus × C. papillosus) and C. ×vanrensselaeri Roof (C. thyrsiflorus × C. incanus). H. McMinn (1944) reported hybrids with C. foliosus.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

... more about "Ceanothus thyrsiflorus"
sparsely puberulent +  and villosulous or glabrate +
perigynous +  and epigynous +
Clifford L. Schmidt† +  and Dieter H. Wilken +
Eschscholtz +
obtuse +  and rounded +
3-veined +  and veined +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
not gland-dotted +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
3[-5]-veined +  and pinnate +
spinulose +, spinose +, serrate +  and entire +
denticulate +, dentate +, crenulate +, crenate +  and serrulate +
elliptic;ovate +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
not thorn-tipped +
glabrous +  and puberulent +
not tuberculate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Blueblossom +
Calif. +, Oreg. +  and Mexico (Baja California) +
10–600 m. +
Sandy or rocky flats and slopes, maritime chaparral, open sites in mixed evergreen and conifer forests. +
free +  and adnate +
shallowly cupulate +  and hemispheric +
axillary +  and terminal +
unisexual +  and bisexual +
paniclelike +  and racemelike +
2.5 cm25 mm <br />0.025 m <br /> (9 cm90 mm <br />0.09 m <br />) +
deciduous +  and persistent +
denticulate;serrulate +
white;usually pale;deep blue +
intrastaminal +
superior +  and inferior +
not fleshy +
perigynous +  and epigynous +
pink +, usually white +  and cream blue or purple +
adnate +  and distinct +
6 +  and 5 +
clawed +, obovate +  and spatulate +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Flowering Mar–Jun. +
2-4-carpellate +
Mém. Acad. Imp. Sci. St. Pétersbourg Hist. Acad. +
pink +, usually white +  and cream blue or purple +
distinct +
spreading +  and incurved +
6 +  and 5 +
keeled;lanceolate;deltate +
not rooting +
ascending +  and erect +
3-veined +  and veined +
Ceanothus thyrsiflorus var. chandleri +  and C. thyrsiflorus var. repens +
Ceanothus thyrsiflorus +
Ceanothus subg. Ceanothus +
species +
paniclelike +  and racemelike +
gland-tipped +
not crested +
puberulent +  and villosulous +
unarmed +  and armed +
polygamous +, dioecious +  and synoecious +