Jump to content

Aesculus californica

From Wikipedia, the free encyclopedia
(Redirected from California buckeye)

Aesculus californica
Secure
Secure (NatureServe)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Sapindaceae
Genus: Aesculus
Species:
A. californica
Binomial name
Aesculus californica
Natural range

Aesculus californica, commonly known as the California buckeye or California horse-chestnut, is a species of flowering plant in the soapberry family native primarily to California and southwestern Oregon. It is a large shrub or small tree, often with several trunks and a broad, rounded crown. It has palmately compound leaves are among the earliest in spring, followed by erect flower clusters of white to pale pink flowers in late spring and large, pear shapes fruit capsules in late summer.

California buckeye is drought deciduous: in drier, more inland areas, its leaves commonly fall off and die during late summer, while specimens in moister coastal environments retain their leaves longer into autumn. The large, glossy seeds and other parts of the plant contain toxic glycoside compounds.

Description

[edit]

Aesculus californica is a large deciduous shrub or small tree, up to 4–12 m (13–39 ft) tall. It typically is multi-trunked, with a crown as broad or broader than it is high. The bark is light gray and smooth.[2]

The leaves are opposite, and palmately compound with five (rarely seven) leaflets. The individual leaflets are 6–17 cm (2.4–6.7 in) long, with a finely serrated margin and pointed tips.[3][4] The leaves are dark green above and paler on the underside and may have downy veins.[4]

The flowers are borne on dense, erect panicles 15–20 cm (6–8 in) long and 5–8 cm (2–3 in) broad. They are fragrant, white to pale pink, and individual flowers are 1-2.5cm long.[4] Each flower has a two-lobed calyx 5-8mm long, and 4 sometimes 5 petals. Five to seven stamens project conspicuously beyond the petals.[2][3] This species is andromonoecious, with the inflorescences producing both staminate and bisexual flowers on the same plant. Only the bisexual flowers are capable of developing into fruit.[5]

The fruit is smoot, leathery pear-shaped capsule 5–8 cm (2–3 in) long. As it matures, the capsule turns brown and splits revealing one large, glossy brown seed, measuring 2–7 cm (0.8–2.8 in).[4][3] The seeds are poisonous.[6]

California buckeye has adapted to its native Mediterranean climate by having an earlier growing season that tracks the availability of moisture. It is among the earliest native woody plants in its range to produce new leaves in spring, and likewise one on the earliest to lose its leaves in late summer. In dry inland populations, the leaves commonly senesce in late spring or summer and are shed as soil moisture evaporates. [2][7] Those growing in coastal regions tend to hold on to their leaves until mid-autumn.[8]

Distribution and habitat

[edit]

California Buckeye is the only Aesculus species native to the western United States.[9][10] A. californica is widely distributed in California, growing in the Klamath Mountains and California Coast Ranges from the Siskiyou Mountains south to Los Angeles County and in the Cascade Range and lower elevations of the Sierra Nevada from Shasta County to Kern County. A small, disjunct population occurs near Gold Hill in the Rogue Valley in Jackson County, Oregon, separated from the California populations by quite a distance.[7]

This species grows in a wide range of conditions: dry slopes, in canyons and along streams generally at low to middle elevations below 1700m.[2] It occurs as scattered individuals in grasslands as an understory shrub in mixed evergreen forests, and as a component or local dominant of chaparral and oak woodlands.[11] In the coastal ranges north of Big Sur it is found growing alone on slopes, or intermingled with valley oak (Quercus lobata), Oregon oak (Q. garryana), coast live oak (Q. agrifolia) and California bay laurel (Umbellularia californica). In the foothills of the Sierra Nevada, A. californica can be found standing alone in grassland at the lowest elevations, intermingled in blue oak woodlands at intermediate elevations, and in mixed evergreen forests of black oak (Q. kelloggii), gray pine (Pinus sabiniana), ponderosa pine (P. ponderosa) and interior live oak (Q. wislizeni) as it nears the limit of its range.[12]

Toxicity and uses

[edit]
Seed of the California Buckeye in its husk

Native American tribes, including the Pomo, Yokuts, and Luiseño, used the poisonous nuts and seeds to stupefy schools of fish in small streams to make them easier to catch.[13] The bark, leaves, and fruits contain neurotoxic glycosides, which causes hemolysis of red blood cells.[14] Buckeye also makes a good fireboard for a bow drill or hand drill.

Native groups occasionally used the plant as a food supply; after boiling and leaching the toxin out of the seeds or nut meats for several days, they could be ground into a flour or meal similar to that made from acorns.[10] The nectar and pollen of the flowers is toxic to honeybees,[10] so the trees should not be planted near apiaries.[14] When the shoots are small and leaves are new, they are lower in toxins and are grazed by livestock and wildlife.[11] The flowers are a rich nectar source for many species of butterflies,[15] and squirrels and chipmunks consume the seeds.[10] Hydroquinone and epicatechin have been isolated from the seeds and have been shown to have allelopathic properties by inhibiting plant growth.[16]

It is used as an ornamental plant for its striking leaf buds, lime green foliage, fragrant white flowers, red-brown foliage in mid to late summer, and architectural silver branches through fall. The tree also acts as a soil binder, which prevents erosion in hilly regions.

Etymology

[edit]

'Aesculus' is Linnaeus' name for horse chestnuts. It is derived from the old Roman name for a different species, Quercus petraea.[17]

'Californica' means 'native to California'.[17]

[edit]

References

[edit]
  1. ↑ IUCN SSC Global Tree Specialist Group.; Botanic Gardens Conservation International (BGCI) (2020). "Aesculus californica". IUCN Red List of Threatened Species. 2020 e.T156820810A156820812. doi:10.2305/IUCN.UK.2020-1.RLTS.T156820810A156820812.en. Retrieved 11 June 2026.
  2. 1 2 3 4 Anderson, Kat (30 May 2006). "California Buckeye" (PDF). USDA Plant guide.
  3. 1 2 3 Stone, William J. (24 June 2026). "Aesculus californica". ucjeps.berkeley.edu. Jepson eFlora. Retrieved 2026-09-05.
  4. 1 2 3 4 "Aesculus californica | Landscape Plants | Oregon State University". landscapeplants.oregonstate.edu. Retrieved 2026-09-05.
  5. ↑ Newell, Elizabeth A. (1991). "Direct and Delayed Costs of Reproduction in Aesculus Californica". Journal of Ecology. 79 (2). [Wiley, British Ecological Society]: 365–378. doi:10.2307/2260719. ISSN 0022-0477.
  6. ↑ Whitney, Stephen (1985). Western Forests (The Audubon Society Nature Guides). New York: Knopf. p. 397. ISBN 0-394-73127-1.
  7. 1 2 Callahan, Frank (2005). "California Buckeye" (PDF). Kalmiopsis. 12: 9–15. ISSN 1055-419X.
  8. ↑ Bakker, Elna S. (1984). An island called California: an ecological introduction to its natural communities. University of California Press. p. 74. ISBN 978-0-520-04948-2. Retrieved 2011-06-11.
  9. ↑ "Lady Bird Johnson Wildflower Center - The University of Texas at Austin". www.wildflower.org. Retrieved 2026-09-05.
  10. 1 2 3 4 Little, Elbert L. (1994) [1980]. The Audubon Society Field Guide to North American Trees: Western Region (Chanticleer Press ed.). Knopf Doubleday Publishing Group. p. 540. ISBN 9780394507613.
  11. 1 2 Howard, Janet L. Aesculus californica, in the USDA Forest Service Fire Effects Information System (Report). USDA Rocky Mountain Research Station, Fire Sciences Laboratory. Retrieved 2011-11-07.
  12. ↑ "CNPS Alliance: Aesculus californica". vegetation.cnps.org. Archived from the original on 2023-08-25. Retrieved 2026-09-05.
  13. ↑ Philip Alexander Munz; David D. Keck (1973). A California Flora. University of California Press. p. 994. ISBN 978-0-520-02405-2. Retrieved 2011-06-20. buckeye.
  14. 1 2 Anderson, Kat; Roderick, Wayne. Plant Guide: California Buckeye, Aesculus californica (Nutt.) Nutt (PDF) (Report). United States Department of Agriculture. Retrieved 2025-05-30.
  15. ↑ Hintsa, Kevin. Watching Butterflies on Mount Diablo (Report). Archived from the original on 2011-11-10. Retrieved 2011-11-07.
  16. ↑ Kubo, Isao; Matsumoto, Akiko; Kozuka, Mutsuo.; Wood, William F. (1985). "Combined Effect on Plant Growth of (-)-Epicatechin and Hydroquinone, Compounds from Aesculus californica NUTT. (Hippocastanaceae)". Chem. Pharm. Bull. 33 (9): 3826–3828. doi:10.1248/cpb.33.3826.
  17. 1 2 Gledhill, David (2008). "The Names of Plants". Cambridge University Press. ISBN 9780521866453 (hardback), ISBN 9780521685535 (paperback). pp 38, 84
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Aesculus_californica&oldid=1373648657"