Ceanothus crassifolius

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordoo: Rosales

Familia: Rhamnaceae
Subfamilia: Ziziphoideae
Tribus: Unplaced Ziziphoids
Genus: Ceanothus
Species: Ceanothus cordulatus
Name

Ceanothus cordulatus Kellogg, 1861
References

Proceedings of the California Academy of Sciences 2:124, t. 39. 1861
USDA, ARS, Germplasm Resources Information Network. Ceanothus cordulatus in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 09-Oct-10.

Vernacular names
English: mountain whitethorn

Ceanothus cordulatus is a species of shrub in the family Rhamnaceae known by the common names mountain whitethorn and whitethorn ceanothus. It is native to California and adjacent sections of Oregon, Nevada, and Baja California, where it grows on mountain ridges and other forested areas. This is a spreading shrub growing usually wider than tall and up to about 1.5 meters. The stems are gray, with the twigs yellow-green in color and fuzzy in texture when new. The evergreen leaves are alternately arranged and up to 3 centimeters long. Each is oval in shape with three ribs and generally not toothed. The leaves may be hairy or not. The inflorescence is panicle-shaped, up to about 4 centimeters long. The flowers are white to off-white with five sepals and five petals. The fruit is a rough, ridged capsule up to half a centimeter long. It has three valves inside, each containing a seed. It is a nitrogen-fixing plant, that is uniquely abundant in old-growth forest conditions when compared to similar types of nitrogen-fixing plants. In addition, Ceanothus cordulatus is known to be an important source of nitrogen patches for significantly longer times than other similar post-disturbance successional shrubs, following disturbance events such as forest fires.[1]
References

Oakley, Brian; North, Malcolm; Franklin, Jerry (July 2003). "The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus". Plant & Soil. 254 (1): 35–46. doi:10.1023/A:1024994914639. S2CID 21805715.

Ceanothus crassifolius is a species of flowering shrub known by the common name hoaryleaf ceanothus. This Ceanothus is found throughout the coastal mountain ranges of the southern half of California, and its range extends into Baja California.[1]

Distribution

Ceanothus crassifolius typically occurs in coastal and montane California chaparral habitat associations. Common flora associates are Toyon (Heteromeles arbutifolia) and Hollyleaf cherry (Prunus ilicifolia).[2] The mountain range systems it is found in include the Southern California Coast Ranges, the Transverse Ranges, and the Peninsular Ranges.[1]
Description

Ceanothus crassifolius is an erect, spreading shrub which can exceed 3 metres (9.8 ft) in height. The branches become long and the younger twigs are fuzzy with white or light brown hairs. The small evergreen leaves have widely spaced teeth along the edges and the undersides are lighter in color and coated with hairs.

The inflorescences are borne on short stalks less than three centimeters long and are small and rounded with tiny white flowers.[1] They can be quite dense and can cover branches thickly, or they may be sparse. The flowers are white, though may have a yellowish or pink tint.

The fruit is a horned capsule less than a centimeter wide.
References

Jepson Manual (1993) University of California, Berkeley . accessed 3.23.2013
C. Michael Hogan (2008) Toyon (Heteromeles arbutifolia), GlobalTwitcher, ed. N. Stromberg Archived July 19, 2009, at the Wayback Machine