Ceanothus thyrsiflorus |
Ceanothus divergens |
|
---|---|---|
blue blossom, blue blossom ceanothus |
Calistoga ceanothus |
|
Habit | 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. | Shrubs, 0.5–1.5 m, sometimes moundlike. |
Stems | erect to ascending, not rooting at nodes; branchlets brown to grayish brown, sometimes glaucous, ± flexible, glabrous or sparsely puberulent. |
|
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. |
not fascicled, spreading; petiole 0–2 mm; blade flat to ± cupped or weakly folded lengthwise, elliptic to ± oblong or obovate, 10–20 × 5–12 mm, base obtuse to cuneate, margins thick or slightly revolute, slightly wavy, spinose-dentate, teeth 5–9(–11), apex sharply acute or retuse with an apical tooth, abaxial surface grayish green, veins strigillose, adaxial surface green, glabrous. |
Inflorescences | terminal, usually racemelike, rarely paniclelike, 2.5–9 cm. |
axillary, 1.2–2.5 cm. |
Flowers | sepals, petals, and nectary usually pale to deep blue, rarely white. |
sepals and petals deep blue to purple; nectary dark blue or purple. |
Capsules | 3–4 mm wide, weakly lobed; valves smooth, viscid, not crested. |
5–6 mm wide, lobed; valves smooth, crested, horns subapical, prominent, erect, intermediate ridges weakly developed. |
2n | = 24. |
= 24. |
Ceanothus thyrsiflorus |
Ceanothus divergens |
|
Phenology | Flowering Mar–Jun. | Flowering Feb–Apr. |
Habitat | Sandy or rocky flats and slopes, maritime chaparral, open sites in mixed evergreen and conifer forests. | Rocky soils apparently derived from serpentine or volcanic substrates, chaparral, oak and pine woodlands. |
Elevation | 10–600 m. (0–2000 ft.) | 100–1000 m. (300–3300 ft.) |
Distribution |
CA; OR; Mexico (Baja California)
|
CA |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ceanothus divergens is restricted to a few localities in Napa and Sonoma counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 90. | FNA vol. 12, p. 103. |
Parent taxa | Rhamnaceae > Ceanothus > subg. Ceanothus | Rhamnaceae > Ceanothus > subg. Cerastes |
Sibling taxa | ||
Synonyms | C. thyrsiflorus var. chandleri, C. thyrsiflorus var. repens | |
Name authority | Eschscholtz: Mém. Acad. Imp. Sci. St. Pétersbourg Hist. Acad. 10: 285. (1826) — (as thyrsiflora) | Parry: Proc. Davenport Acad. Nat. Sci. 5: 173. (1889) |
Web links |