Heteromeles

Heteromeles
A fruiting toyon in San Diego County
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Rosaceae
Subfamily: Amygdaloideae
Tribe: Maleae
Subtribe: Malinae
Genus: Heteromeles
M.Roem. nom. cons. 1847
Species:
H. arbutifolia
Binomial name
Heteromeles arbutifolia
Natural range
Synonyms
  • Photinia arbutifolia Lindl.
  • Crataegus arbutifolia W.T.Aiton nom. illeg.
  • Heteromeles fremontiana Decaisne
  • Heteromeles salicifolia (C.Presl) Abrams
  • Photinia salicifolia C.Presl

Heteromeles arbutifolia (/ˌhɛtɪroʊˈmiːliːz ɑːrˌbjuːtɪˈfoʊliə/, more commonly /ˌhɛtəˈrɒməliːz/ by Californian botanists), commonly known as toyon, is a perennial evergreen shrub or small tree with distinctive red fruits native to California, Oregon and Mexico. It is the sole species in the genus Heteromeles.

Description

Toyon typically grows from 2–5 meters (7–16 ft), rarely up to 10 m in shaded conditions, and has a rounded to irregular top. Its leaves are evergreen, alternate, sharply toothed, have short petioles, and are 5–10 centimeters (2–4 in) in length and 2–4 cm (0.8–1.6 in) wide. In the early summer it produces small white flowers 6–10 millimeters (1⁄4–3⁄8 in) diameter in dense terminal corymbs. Flowering peaks in June.

The five petals are rounded. The fruit is a small pome, 5–10 mm across, bright red and berry-like, produced in large quantities, developing in August or September and maturing in December.

Taxonomy

The genera Photinia, Aronia, Pourthiaea, and Stranvaesia have historically been variously combined by different taxonomists. The genus Heteromeles as originally published by Max Joseph Roemer was monospecific, including Photinia arbutifolia Lindl. (1820), as H. arbutifolia (Lindl.) M.Roem, but the name was illegitimate (superfluous) because it included the type of the genus Photinia. This has since been corrected by conservation, and the name is therefore often written as Heteromeles M.Roem. nom. cons. (1847).[citation needed]

Varieties

Distribution and habitat

Toyon fruiting in chaparral on Black Mountain, San Diego County, California

It is native to extreme southwest Oregon, California, and the Baja California Peninsula.

Toyon is a prominent component of the coastal sage scrub plant community, and is a part of drought-adapted chaparral and mixed oak woodland habitats. It is also known by the common names Christmas berry and California holly.

Ecology

Mature toyon fruit is eaten by many wildlife species, especially birds. The fruit are consumed by California quail, mockingbirds, band-tailed pigeons, American robins, cedar waxwings, hermit thrushes and raccoons. The tall shrub communities in which toyons grow also provide nesting and hiding cover for birds and small mammals. The plants are visited frequently by butterflies.


Toyon persists in the fire-prone chaparral environment with vigorous resprouting: seeds are destroyed in fire and the plant requires fire free periods for successful seedling establishment and population expansion.

Toxicity

Toyon pomes are acidic and astringent, and contain a small amount of cyanogenic glycosides, which break down into hydrocyanic acid on digestion. This is removed by mild cooking. Most fruit from plants in the family Rosaceae, including apples, apricots, peaches, cherries, and plums, contain cyanide.

A 2016 study found 5 g of the dried berries (used as a treatment for Alzheimer's) to be safe. The study also found no cyanogenic compounds in the plant.

Uses

Plant fruiting on Mount Diablo, Contra Costa County

Indigenous Uses

Toyon is known by several names to different Indigenous tribes and linguistic groups (Tongva and ʔívil̃uqaletem: ashuwet; Barbareño, Cruzeño, and Inseño Chumashan languages: qwe').

The pomes provided food for local Native American tribes, such as the Chumash, Tongva, and Tataviam. The pomes also can be made into a jelly. Native Americans also made a tea from the leaves as a stomach remedy. Most were dried and stored, then later cooked into porridge or pancakes. Later settlers added sugar to make custard and wine. The plants were also often cooked over a fire to remove the slightly bitter taste by Californian tribes.

The Tongva ate the berries fresh, boiled and left them in an earthen oven for 2 to 3 days, roasted them, or made them into a cider. Pulverized flowers were steeped into hot water to make tea which could be used to ease gynecological ailments. For stomach pains, bark and leaves are steeped in hot water to make tea. The same tea can serve as a seasonal tonic and ease other body pains. Also, applying mashed ashuwet to sores eases pain. Infected wounds are washed using an infusion of bark and leaves. The ʔívil̃uqaletem often consumed the fruit both raw and cooked.

Phytochemistry

The plant has been used as a treatment for Alzheimer's disease by indigenous people of California and recent research has found a number of active compounds that are potentially beneficial to Alzheimer's treatment. These include icariside compounds, which protect the blood-brain barrier and prevent infiltration of inflammatory cells into the brain.

Cultivation

Toyon is cultivated as an ornamental shrub, but can be trained into a multi-stemmed small tree: a shape that must be maintained by constant pruning. It grows in sun or partial shade and prefers well drained soil. Established plants are drought tolerant, making it suitable for xeriscape gardening. Toyon can be grown in domestic gardens and has been cultivated as an ornamental plant in southern England at the Ventnor Botanic Garden.

Like many other genera in the Rosaceae tribe Maleae, toyon includes some cultivars that are susceptible to fireblight. Toyon is less of a fire hazard than some chaparral plants.

In culture

In 1921, collecting toyon branches for Christmas became so popular in Los Angeles that the State of California passed a law forbidding collecting on public land or on any land not owned by the person picking any plant without the landowner's written permission (CA Penal Code § 384a).

Toyon was adopted as the official native plant of the city of Los Angeles by the LA City Council on April 17, 2012.

See also

References

  1. ↑ IUCN SSC Global Tree Specialist Group.; Botanic Gardens Conservation International (BGCI). (2020). "Heteromeles arbutifolia". IUCN Red List of Threatened Species. 2020 e.T156822115A156822117. doi:10.2305/IUCN.UK.2020-1.RLTS.T156822115A156822117.en. Retrieved 23 September 2021.
  2. ↑ Jepson Flora Project (1993) Heteromeles arbutifolia, University of California, Berkeley
  3. 1 2 James B. Phipps (2015), "Heteromeles arbutifolia (Lindley) M. Roemer, Fam. Nat. Syn. Monogr. 3: 105. 1847", Flora of North America, vol. 9
  4. ↑ Tropicos.org, retrieved 11 November 2016
  5. ↑ Sunset Western Garden Book, 1995:606–607
  6. ↑ Heteromeles arbutifolia at iNaturalist
  7. ↑ "Heteromeles arbutifolia, in Jepson Flora Project". Regents of the University of California. Retrieved 14 November 2013.
  8. 1 2 3 4 5 McMurray, Nancy E. (1990). "Heteromeles arbutifolia". Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Retrieved 2026-09-08.
  9. 1 2 Nesom, G.L. & Gandhi, K. (2009), "(1884–1885) Proposals to conserve the names Photinia, with a conserved type, and Heteromeles (Rosaceae)", Taxon, 58 (1): 310–311, Bibcode:2009Taxon..58..310N, doi:10.1002/tax.581041
  10. ↑ International Code of Nomenclature for algae, fungi, and plants: Appendices II-VIII (Appendix III)
  11. 1 2 3 James B. Phipps (2015), "Heteromeles M. Roemer, Fam. Nat. Syn. Monogr. 3: 100, 105. 1847. [name conserved]", Flora of North America, vol. 9
  12. ↑ Rebman, J. P.; Gibson, J.; Rich, K. (2016). "Annotated checklist of the vascular plants of Baja California, Mexico" (PDF). Proceedings of the San Diego Society of Natural History. 45: 245.
  13. ↑ de la Luz, J. L. L., Rebman, J. P., & Oberbauer, T. (2003). On the urgency of conservation on Guadalupe Island, Mexico: is it a lost paradise?. Biodiversity & Conservation, 12(5), 1073-1082.
  14. ↑ Raabe, R. D., & Gardner, M. W. (1972). Scab of Pyracantha, loquat, toyon, and kageneckia. Phytopathology, 62, 914-916.
  15. ↑ "Final Environmental Impact Statement - Appendices" (PDF). Smith River National Recreation Area Restoration and Motorize Travel Management. United States Department of Agriculture: 192. December 2016. Archived from the original (PDF) on September 20, 2021. Heteromeles arbutifolia is found in Oregon and the location southwest of Pappas Flat is not the northernmost site in the Pacific Northwest. Additionally, this site is adjacent to Highway 199 and will not be affected by the proposed actions, and is outside the geographic scope of the project.
  16. ↑ Wood, Wendell (February 2008). "Toyon Joins the List of Oregon's Native Shrubs" (PDF). Bulletin of the Native Plant Society of Oregon. 41 (2): 11, 18.
  17. ↑ C.M. Hogan, 2008
  18. ↑ Kaplan, Alan; Hawkes, Alison (December 22, 2016), "Ask The Naturalist: How Important Are Red Toyon Berries To the Winter Food Chain?", Bay Nature
  19. ↑ Griffith, Linda Lewis (4 February 2020). "Toyon". University of California: Agriculture and Natural Resources. Retrieved 8 September 2026.
  20. ↑ Jim Moore (21 November 2017). "Toyon – California's Own Christmas Berry Can Be Toxic |". mountainvalleyliving.com. Retrieved 2021-12-27.
  21. 1 2 3 Wang; Dubois; Young; Lien; Adams (7 Jul 2016). "Heteromeles Arbutifolia, a Traditional Treatment for Alzheimer's Disease, Phytochemistry and Safety". Medicines. 3 (3): 17. doi:10.3390/medicines3030017. PMC 5456246. PMID 28930127.
  22. ↑ Timbrook, Jan (2023). Chumash Ethnobotany: plant knowledge among the Chumash people of southern California (2nd ed.). Santa Barbara Museum of Natural History. ISBN 9780936494029.
  23. ↑ "Ethnobotany of southern California native plants: Toyon (Heteromeles arbutifolia)". EthnoHerbalist.
  24. 1 2 Bean, John Bean; Saubel, Katherine Siva (1969). Temalpakh (from the Earth): Cahuilla Indian Knowledge and Usage of Plants. Malki Museum Press. ISBN 978-0-939046-24-9. Archived from the original on 2023-05-21. Retrieved 2021-02-19.
  25. ↑ "Ashuwet". Tongva Medicinal Plants.
  26. ↑ "Heteromeles arbutifolia (Toyon)". University of California: Agriculture and Natural Resources. June 2025. Retrieved 7 September 2026.
  27. ↑ "Toyon". Calscape. Retrieved 2026-09-08.
  28. ↑ "Collection records for Heteromeles arbutifolia". INHS Collections Data. Illinois Natural History Survey. Retrieved 2026-09-08.
  29. ↑ Austin Hagan, Edward Sikora, William Gazaway, Nancy Kokalis- Burelle, 2004. Fire Blight on Fruit Trees and Woody Ornamentals, Alabama A&M and Auburn Universities
  30. ↑ November 11, 1921 Santa Ana Register, "Holly Trees of County to be saved by Vandals" State Legislature enacts law prohibiting the mutilation or sale of California Holly taken from public lands.
  31. ↑ McKINNEY, JOHN (December 6, 1986). "California Holly Adds Color to Trail Up Mt. Hollywood". Los Angeles Times. p. 12.
  32. ↑ California Penal Code Section 384a Archived 2009-06-27 at the Wayback Machine
  33. ↑ "Item No. (28)" (PDF). Journal/Council Proceedings. LA City Council. Retrieved 23 November 2013.