Aesculus californica

Aesculus californica is a large deciduous shrub or small tree, up to {{Convert|4-12|m|ft|abbr = on}} tall, with gray bark often coated with lichens and mosses. It typically is multi-trunked, with a crown as broad as it is high. Trees are long lived, with an estimated lifespan between 250–280 (300 maximum) years. The leaves are dark green, palmately compound with five (rarely seven) leaflets. Each leaflet is {{Convert|6-17|cm|abbr = on}} long, with a finely toothed margin and (particularly in spring) downy surfaces. The leaves are tender and prone to damage from both spring freezing or snow and summer heat and desiccation.{{cn|date=March 2023}}

The flowers are sweet-scented, white to pale pink, borne on erect panicles {{Convert|15-20|cm|4 = 0|abbr = on}} long and {{Convert|5-8|cm|4 = 0|abbr = on}} broad. The fruit is a fig-shaped capsule {{Convert|5-8|cm|4 = 0|abbr = on}} long, containing a large, round, orange-brown seed, measuring {{Convert|2-7|cm|4 = 1|abbr = on}}. The seeds are poisonous{{cite book |last=Whitney |first=Stephen |title=Western Forests (The Audubon Society Nature Guides) |date=1985 |publisher=Knopf |location=New York |isbn=0-394-73127-1 |page=[https://archive.org/details/westernforests00whit/page/397 397] |url=https://archive.org/details/westernforests00whit/page/397 }} and are the largest known of any temperate (non-tropical) plant species.

A. californica has adapted to its native Mediterranean climate by growing during the wet late winter and spring months and entering dormancy in the dry summer months, though those growing in coastal regions tend to hold on to their leaves until mid-autumn.{{cite book |author=Bakker |first=Elna S. |url=https://books.google.com/books?id=VIIv2O-nF4AC&q=An+Island+Called+California |title=An island called California: an ecological introduction to its natural communities |publisher=University of California Press |year=1984 |isbn=978-0-520-04948-2 |page=74 |access-date=2011-06-11}}

The only Aesculus variety native to the West,{{cite book |last=Little |first=Elbert L. |title=The Audubon Society Field Guide to North American Trees: Western Region |year=1994 |orig-year=1980 |publisher=Knopf |isbn=0394507614 |edition=Chanticleer Press|page=540}} A. californica is widely distributed in California, growing along the central coast and in the lower elevations of the Sierra Nevada and Cascade Range. Its range extends to the foothills of the Siskiyou Mountains in the Rogue Valley in Oregon. A small disjunct population is found in the Chino Hills near Chino, California.{{cn|date=March 2023}}

It is found growing in a wide range of conditions from crowded, moist, semi-shaded canyon bottoms to dry south-facing slopes and hilltops. 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.{{cn|date=March 2023}}

File:Aesculus californica-29.jpg

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.{{cite book |title=A California Flora |author=Philip Alexander Munz |author2=David D. Keck |year=1973 |publisher=University of California Press |isbn=978-0-520-02405-2 |page=[https://archive.org/details/californiafloras00phil/page/994 994] |url=https://archive.org/details/californiafloras00phil |url-access=registration |quote=buckeye. |access-date=2011-06-20 }} The bark, leaves, and fruits contain neurotoxic glycosides, which causes hemolysis of red blood cells. 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. The nectar and pollen of the flowers is toxic to honeybees, so the trees should not be planted near apiaries.{{cite report |url=http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf |title=California Buckeye, in the USDA NRCS Plant Guide |author=Anderson |first1=Kat |last2=Roderick |first2=Wayne |date= |publisher=United States Department of Agriculture |access-date=2011-06-20}} When the shoots are small and leaves are new, they are lower in toxins and are grazed by livestock and wildlife.{{cite report |title=Aesculus californica, in the USDA Forest Service Fire Effects Information System |author=Howard, Janet L.|publisher=USDA Rocky Mountain Research Station, Fire Sciences Laboratory|url=http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html|access-date=2011-11-07 }} The flowers are a rich nectar source for many species of butterflies,{{cite report |url=http://www.mdia.org/Wildlife/wbutterfly.htm |title=Watching Butterflies on Mount Diablo |author=Hintsa |first=Kevin |date= |access-date=2011-11-07 |archive-url=https://web.archive.org/web/20111110102808/http://mdia.org/Wildlife/wbutterfly.htm |archive-date=2011-11-10 |url-status=dead}} and squirrels and chipmunks consume the seeds. Hydroquinone and epicatechin have been isolated from the seeds and have been shown to have allelopathic properties by inhibiting plant growth.{{cite journal | last1 = Kubo | first1 = Isao | last2 = Matsumoto | first2 = Akiko | last3 = Kozuka | first3 = Mutsuo. | last4 = Wood | first4 = William F. | year = 1985 | title = Combined Effect on Plant Growth of (-)-Epicatechin and Hydroquinone, Compounds from Aesculus californica NUTT. (Hippocastanaceae) | journal = Chem. Pharm. Bull. | volume = 33 | issue = 9 | pages = 3826–3828 | doi= 10.1248/cpb.33.3826}}

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.

'Aesculus' is Linnaeus' name for horse chestnuts. It is derived from the old Roman name for a different species, Quercus petraea.Gledhill, David (2008). "The Names of Plants". Cambridge University Press. {{ISBN|9780521866453}} (hardback), {{ISBN|9780521685535}} (paperback). pp 38, 84

'Californica' means 'native to California'.

File:Aesculus californica-7.jpg|Buds opening in February

File:Aesculus californica-11.jpg|Foliage around March

File:Californicaspike.JPG|Flower spike in May

File:California buckeyes forming in july.jpg|Buckeyes forming in July

File:Aesculus californica kz7.jpg|Buckeyes grow and foliage dies back (September)

File:Aesculus californica Mount Diablo.jpg|Buckeye husks split open (November)

File:Aesculus californica seeds in basket 2003-12-01.jpg|Harvested buckeyes

File:Aesculus californica-Seed-8.jpg|Buckeye sprouting (January)

{{Reflist}}

• [http://npsoregon.org/kalmiopsis/kalmiopsis12/buckeye.pdf Callahan, F. 2005 Kalmiopsis Journal, Vol. 12, 2005 Plant of the Year, California Buckeye (Aesculus californica (Spach.) Nutt.) Native Plant Society of Oregon]. {{ISSN|1055-419X}}. (.pdf)
• {{cite book |last=Casebeer |first=M. |year=2004 |title=Discover California Shrubs |location=Sonora, California |publisher=Hooker Press |isbn=0-9665463-1-8}}
• {{cite book |last=Bakker |first=E. |year=1971 |title=An Island Called California |location=Berkeley, California |publisher=University of California Press |isbn=0-520-04948-9}}
• [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?Aesculus+californica Jepson Flora Project: Aesculus californica]
• [http://plants.usda.gov/java/profile?symbol=aeca USDA Plants Profile for Aesculus californica (California buckeye)]
• [http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=111 Calflora database – Aesculus californica]
• [https://web.archive.org/web/20170525024407/http://www.plantmaps.com/nrm/aesculus-californica-california-buckeye-native-range-map.php Interactive Distribution Map of Aesculus californica]
• [http://calphotos.berkeley.edu/cgi/img_query?where-taxon=Aesculus+californica Aesculus californica – U.C. Photo gallery]

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californica

Category:Flora of California

Category:Flora of Oregon

Category:Plants used in Native American cuisine

Category:Pre-Columbian California cuisine

Category:Drought-tolerant trees

Category:Ornamental trees

Category:Flora without expected TNC conservation status