Ceanothus cuneatus var. rigidus

(Nuttall) Hoover

Leafl. W. Bot. 10: 350. 1966.

Common names: Monterey buck brush
EndemicConservation concern
Basionym: Ceanothus rigidus Nuttall in J. Torrey and A. Gray, Fl. N. Amer. 1: 268. 1838
Synonyms: C. rigidus var. albus Roof C. rigidus var. pallens Sprague
Treatment appears in FNA Volume 12. Treatment on page 100. Mentioned on page 99.

Shrubs, 0.5–1.5 m. Stems erect, ascending, or spreading; branchlets gray to grayish brown. Leaf blades of fascicled and non-fascicled leaves flat to ± cupped, widely obovate to orbiculate, 4–10 × 4–6 mm, length usually less than 2 times width, margins 5–9-toothed, apex rounded to truncate. Flowers: sepals, petals, and nectary usually pale to deep blue, rarely white. Capsules 5–6 mm wide. 2n = 24.


Phenology: Flowering Feb–Apr.
Habitat: Sandy soils, flats, dune swales, maritime chaparral, pine forests.
Elevation: 10–400 m.

Discussion

The typical form of var. rigidus is restricted almost entirely to sandy soils of coastal hills and mesas in the southern Monterey Bay region, although plants with denticulate leaf blades occur near Morro Bay in San Luis Obispo County. The name Ceanothus rigidus var. albus Roof was applied to low-growing plants with spreading stems and white flowers. Such plants apparently have been extirpated on the Monterey peninsula and survive only in cultivation.

Selected References

None.

Lower Taxa

None.
Clifford L. Schmidt† +  and Dieter H. Wilken +
(Nuttall) Hoover +
Ceanothus rigidus +
Monterey buck brush +
10–400 m. +
Sandy soils, flats, dune swales, maritime chaparral, pine forests. +
Flowering Feb–Apr. +
Leafl. W. Bot. +
Endemic +  and Conservation concern +
C. rigidus var. albus +  and C. rigidus var. pallens +
Ceanothus cuneatus var. rigidus +
Ceanothus cuneatus +
variety +