Mountain whitethorn (Ceanothus cordulatus, Proc. Calif. Acad. Sci. 2: 124 (1863))

Family: Rhamnaceae

Author: Kellogg

Bibliography: Proc. Calif. Acad. Sci. 2: 124 (1863)

Year: 1863

Status: accepted

Rank: species

Genus: Ceanothus

Vegetable: Unknown

Observations: Oregon to Mexico (N. Baja California)

Description

Mountain Whitethorn (Ceanothus cordulatus) is a resilient and hardy shrub native to the varied and rugged terrains stretching from Oregon to northern Baja California in Mexico. As a member of the Rhamnaceae family, this plant is well-adapted to thrive in mountainous environments, often found gracing the sun-soaked slopes and open spaces of its broad geographical range.

First described by Killogg and documented in the ‘Proceedings of the California Academy of Sciences’ in 1863, Mountain Whitethorn has since been recognized for both its ecological significance and its unique botanical characteristics. This evergreen shrub typically grows in dense thickets, providing useful cover and habitat for local wildlife, while also playing a crucial role in soil stabilization and ecosystem dynamics in its native regions.

The foliage of Ceanothus cordulatus is characterized by small, rigid, and glossy green leaves that retain their vibrancy throughout the year. This plant’s stems are armed with numerous thorns, a feature that likely inspired its common name and offers a natural defense against herbivores. In addition to its practical defenses, Mountain Whitethorn produces stunning, delicate clusters of white to pale blue flowers. These blossoms appear in abundance during the late spring and early summer months, creating a striking contrast against the plant’s dark green foliage and often drawing the attention of pollinators, including bees and butterflies.

Aside from its aesthetic appeal, Mountain Whitethorn contributes significantly to the botanical community. As a pioneer species, it is one of the first to colonize disturbed or degraded areas, facilitating the process of ecological succession. Its roots harbor nitrogen-fixing bacteria, which enriches the soil with essential nutrients, promoting the growth of other plant species in the area.

While resilient, Mountain Whitethorn demands particular growing conditions, favoring well-drained soils and full sunlight exposure. It is notably drought-tolerant, a characteristic that makes it especially suited to the dry, arid climates found within its native range. However, its preference for higher altitudes and specific soil types can pose challenges for gardeners attempting to cultivate it outside its natural habitat.

Thus, Mountain Whitethorn stands as a testament to plant resilience and adaptability, integral to its native ecosystems across western North America. Its history, ecological role, and striking beauty make it a noteworthy subject of study and appreciation in the botanical realms.

Common Names

Eng: mountain whitethorn, whitethorn ceanothus
En: Mountain whitethorn, Whitethorn ceanothus

Synonyms

Distribution

• California (native)
• Mexico Northwest (native)
• Nevada (native)
• Oregon (native)

Additional Images

Leaf

Taken Aug 13, 2020 by taylor drake (cc-by-sa)

Taken Jul 25, 2020 by J fry (cc-by-sa)

Taken Aug 22, 2022 by Carlos Roche Calvo (cc-by-sa)

Taken Sep 26, 2022 by voxferalis (cc-by-sa)

Taken Feb 19, 2008 by EOL − Steve Matson (cc-by-nc)

Habit

Taken Oct 16, 1998 by EOL − Charles Webber (cc-by-nc-sa)

Taken Feb 19, 2011 by EOL − Wynn Anderson (cc-by-nc-sa)

Taken Oct 15, 1998 by EOL − Charles Webber (cc-by-nc-sa)

Taken Dec 23, 2009 by EOL − Barry Breckling (cc-by-nc-sa)

Taken Feb 19, 2011 by EOL − Wynn Anderson (cc-by-nc-sa)

Fruit

Taken Jul 3, 2014 by EOL − Donna Pomeroy (cc-by-nc)

Taken Nov 28, 2014 by EOL − Jon Sullivan (cc-by-nc)

Taken Aug 3, 2006 by EOL − Steve Matson (cc-by-nc)

Taken Aug 3, 2006 by EOL − Steve Matson (cc-by-nc)

Taken Feb 19, 2008 by EOL − Steve Matson (cc-by-nc)

Flower

Taken Oct 15, 1998 by EOL − Charles Webber (cc-by-nc-sa)

Taken Oct 15, 1998 by EOL − Charles Webber (cc-by-nc-sa)

Taken Feb 24, 1999 by EOL − Charles Webber (cc-by-nc-sa)

Taken Jul 2, 2003 by EOL − Steve Matson (cc-by-nc)

Taken Nov 1, 2015 by EOL − Barry Breckling (cc-by-nc-sa)

Sources

• WFO (No URL)
• IPNI (No URL)
• GBIF (https://www.gbif.org/species/3039317)
• POWO (http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:716786-1)
• PlantNet (https://identify.plantnet.org/species/the-plant-list/Ceanothus cordulatus Kellogg)

Specifications

Growth