Toyon :

Christmas Berry, California Holly
Heteromeles arbutifolia
NATIVE

Description (Jepson, PlantID.net)

Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
Rose Family (Rosaceae)
Only species in its genus
Perennial shrub or small tree
Shiny, serrated leaves, alternating along stem
Flowers
- Inflorescence (flower arrangement) is a domed panicle (branching stem with flowers opening from the bottom up)
- White, urn-shaped flowers
  - 5 separate petals attach to a floral cup (hypanthium)
- Urn-shaped hypanthium (floral cup formed from the fusion of petals, sepals, and stamens)
- Ovary inferior (below the attachment of other flower parts)
Fruit is a small orange to red “berry,” technically a pome (a fleshy fruit derived from a floral tube enclosing an inferior ovary)
Height to ~30 ft.

Distribution

Native to California
- Grows in coastal sage scrub, chaparral, and mixed oak woodlands
- See Calflora for statewide observations of this plant
Outside California, grows into Baja California, Mexico
Grows at elevations to 4,300 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

Wildlife
- Many animals rely on the berries as a winter food source (Marionchild 2014)
  - Birds, including hermit thrush (Catharus guttatus), American robin (Turdus migratorius), and cedar waxwing (Bombycilla cedrorum)
  - Mammals, including coyotes and bears
- Dusky-footed woodrats are the only mammals known to eat mature toyon leaves (Marionchild 2014)
  - Leaching rooms in their stick houses help break down toxins
  - Bacteria in their digestive tract help digest toxins
Native people
- Fruit was eaten toasted, boiled, or baked
- Infusion from bark and leaves used to treat infected wounds
- Dried fruits were eaten as a treatment for dementia (Wang 2013)
- Trees were actively managed by pruning and burning, stimulating many positive effects (Anderson 2005)
  - Vigorous and straighter shoots
  - Larger and more numerous fruits
  - Less congested canopies
  - Reduced insect infestations
  - Recycled nutrients
CAUTION – Fruits contain a cyanide compound that in large amounts is toxic to humans

Name Derivation

Heteromeles (het-er-OH-mi-lees) – from the Greek hetero-, “different,” and the Latin malus, “apple,” suggesting a comparison to apples, which are also in the Rose family: the fruit of both are pomes
arbutifolia (ar-bew-ti-FO-lee-a) – from the genus Arbutus, in the Heath Family, probably related to the Latin arbuscular, “little tree” or “shrub,” and folio, “leaf,” as the leaves are similar to those of the Spanish madrone (Arbutus unedo)
Toyon – derived from an Ohlone word for the plant
- One of just a few California native plants still commonly called by a Native people’s name

Notes

Toyon has several mechanisms for protecting its leaves and berries
- Leaves
  - Leaves contain bitter tannins and toxic levels of cyanide; young leaves have the highest of these compounds (Dement and Mooney 1974)
  - Mature leaves are tough, waxy, and serrated
- Berries
  - Immature berries have high levels of bitter tannins and cyanide, plus low levels of sugar
  - Mature berries have an inviting red color and higher sugar levels; cyanide moves from the flesh to the seeds
Host to the fungus-like microorganism Phytophthora ramorum, which causes Sudden Oak Death (SOD)
- At Edgewood, the two species known to be highly susceptible to SOD are coast live oak (Quercus agrifolia var. agrifolia) and Pacific madrone saplings (Arbutus menziesii)
- For a complete list of known hosts and host associates see USDA Risk Analysis for Phytophthora ramorum, pp.6-9
The evergreen boughs with their bright red fruits reminded Southern California settlers of holly, leading to the alternative common names Christmas berry and California holly
- Hollywood was likely named for the abundance of this plant in the Hollywood hills (Keeler 2015)
- The use of toyon branches for Christmas decorations became so popular in the 1920s that California passed a law prohibiting their collection on public land
- Toyon became the official native plant of Los Angeles in 2012

ID Tips

May also be confused at Edgewood with other evergreen trees/shrubs with similar leaves
- California coffeeberry (Frangula californica ssp. californica)
- Pacific madrone (Arbutus menziesii)
- California bay (Umbellularia californica)

At Edgewood

Found in chaparral and woodlands
- See iNaturalist for observations of this plant
Flowers June – July
Fruits in winter

Specific References

Anderson, M.K. 2005. Tending the Wild. University of California, Berkeley. Pp. 234-235; 274-280.

Marionchild, K. 2014. Secrets of the Oak Woodlands: Plants and Animals among California’s Oaks. Heyday, Berkeley, California.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.

Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Harris, J.G., and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.

Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.