SafePlants

Ceanothus purpureus: Hollyleaf Ceanothus

Ceanothus purpureus, commonly known as Hollyleaf Ceanothus or Napa Ceanothus, is a shrub species belonging to the buckthorn family, Rhamnaceae.

Taxonomy and Nomenclature

• Scientific Name: Ceanothus purpureus
• Common Names: Hollyleaf Ceanothus, Napa Ceanothus, Holly Leaf Mountain Lilac
• Family: Rhamnaceae (Buckthorn Family)
• Genus: Ceanothus
• Synonym: Ceanothus jepsonii var. purpureus (Jeps.) Jeps.

Distribution and Habitat

• Ceanothus purpureus is endemic to California and specifically found in northern parts of the state.
• It thrives on dry, shrub-covered, rocky, volcanic slopes.

Morphological Characteristics and Growth Habits

• It is an evergreen shrub, typically growing up to 2 meters (6ft 7in) in height.
• Hollyleaf Ceanothus can develop like a tree, growing in height and developing a bare stem, creating a thick crown.
• The hybrid 'Blue Jeans' variety has small, holly-like leaves.

Ecological Role

• Hollyleaf Ceanothus is considered threatened, rare, and endangered in California by the California Native Plant Society.

Interactions with Other Organisms

• Cynipid wasps can be found on Ceanothus leaves, causing galls.

Additional Information

• Hardy to zone (UK) 8.
• Flowers bloom from April to June and are hermaphrodite.
• 'Blue Jeans' hybrid Ceanothus needs full sun to retain its color.

Resources

• RHS (Royal Horticultural Society)
• Rogers Trees and Shrubs
• Germplasm Resources Information Network
• Discover Life
• Dave's Garden
• Las Pilitas Nursery (for the 'Blue Jeans' variety)

Quirky Facts

• Ceanothus was the subject of a dissertation.
• Hollyleaf Ceanothus is described as being found on "other-worldly" locations.