From Wikipedia, the free encyclopedia Acorn
Acorn
Acorns play an important role in forest ecology when
oaks are the dominant species or are plentiful.[1] The vol-
ume of the acorn crop may vary wildly, creating great
abundance or great stress on the many animals depen-
dent on acorns and the predators of those animals.[2]
Acorns, along with other nuts, are termed mast.
Wildlife which eat acorns as an important part of
their diets include birds, such as jays, pigeons, some
ducks, and several species of woodpeckers. Small mam-
mals that feed on acorns include mice, squirrels and sev-
eral other rodents.
Large mammals, such as pigs, bears, and deer, also
consume large amounts of acorns; they may constitute
up to 25% of the diet of deer in the autumn.[3] In Spain
and Portugal, pigs are still turned loose in dehesas (large
oak groves) in the autumn, to fill and fatten themselves
on acorns. However, acorns are toxic to some other ani-
mals, such as horses.
The larvae of some moths and weevils also live in
young acorns, consuming the kernels as they develop.[4]
Acorns of Sessile Oak Acorns are attractive to animals because they are
large and thus efficiently consumed or cached. Acorns
The acorn or oak nut is the nut of the oaks and their
acorn, nut, are also rich in nutrients. Percentages vary from species
close relatives (genera Quercus and Lithocarpus, in the to species, but all acorns contain large amounts of pro-
family Fagaceae). It usually contains a single seed (rarely tein, carbohydrates and fats, as well as the minerals cal-
two seeds), enclosed in a tough, leathery shell, and borne cium, phosphorus and potassium, and the vitamin niacin.
in a cup-shaped cupule. Acorns vary from 1–6 cm long Total food energy in an acorn also varies by species, but
and 0.8–4 cm broad. Acorns take between about 6 and 24 all compare well with other wild foods and with other
months (depending on the species) to mature; see List of nuts.[5]
Quercus species for details of oak classification, in which Acorns also contain bitter tannins, the amount vary-
acorn morphology and phenology are important factors. ing with the species. Since tannins, which are plant
polyphenols, interfere with an animal’s ability to metab-
olize protein, creatures must adapt in different ways to
Ecological role use the nutritional value acorns contain. Animals may
preferentially select acorns that contain fewer tannins.
Animals that cache acorns, such as jays and squirrels,
may wait to consume some of these acorns until suffi-
cient groundwater has percolated through them to leach
out the tannins. Other animals buffer their acorn diet
with other foods. Many insects, birds, and mammals me-
tabolize tannins with fewer ill effects than humans.
Species of acorn that contain large amounts of tan-
nins are very bitter, astringent, and potentially irritating
if eaten raw. This is particularly true of the acorns of red
oaks. The acorns of white oaks, being much lower in tan-
nins, are nutty in flavor, which is enhanced if the acorns
are given a light roast before grinding.
Tannins can be removed by soaking chopped acorns
A group of acorns on a branch in several changes of water, until water no longer turns
brown. Being rich in fat, acorn flour can spoil or get
1
From Wikipedia, the free encyclopedia Acorn
moldy easily and must be carefully stored. Acorns are al- trients), ideally a minimum of 20–30 m from the parent
so sometimes prepared as a massage oil. tree[citation needed].
Acorns of the white oak group, Leucobalanus, typically Many animals eat unripe acorns on the tree or ripe
start rooting as soon as they are in contact with the soil acorns from the ground, with no reproductive benefit
(in the fall), then send up the leaf shoot in the spring. to the oak, but some animals, such as squirrels and jays
serve as seed dispersal agents. Jays and squirrels that
Dispersal agents scatter-hoard acorns in caches for future use, effectively
plant acorns in a variety of locations in which it is possi-
ble for them to germinate and thrive.
Although jays and squirrels retain remarkably large
mental maps of cache locations and return to consume
them, the odd acorn may be lost, or a jay or squirrel may
die before consuming all of its stores. A small number of
acorns manage to germinate and survive, producing the
next generation of oaks.
Scatter-hoarding behavior depends on jays and squir-
rels associating with plants that provide good packets
of food that are nutritionally valuable, but not too big
for the dispersal agent to handle. The beak sizes of jays
determine how large acorns may get before jays ignore
them.
Acorns are a vital food source for squirrels. Acorns germinate on different schedules, depending
on their place in the oak family. Once acorns sprout, they
are less nutritious, as the seed tissue converts to the indi-
gestible lignins that form the root.[6]
Cultural relevance
In some human cultures, acorns once constituted a di-
etary staple, though they are now generally considered
a minor food with the exception of Native American and
Korean cultures.
Several indigenous human cultures have devised tra-
ditional acorn-leaching methods that involved tools and
that were traditionally passed on to their children by
word of mouth.[7][8]
Mythology
The Norse legend that Thor sheltered from a thunder-
storm under an oak tree has led to the belief that having
an acorn on a windowsill will prevent a house from being
struck by lightning, hence the popularity of window
blind pulls decorated as acorns.
As food
Acorns served an important role in early human history
and were a source of food for many cultures around the
Ponies eating acorns world.[9] For instance, the poorer Ancient Greeks would
eat acorns in their food and in the Jōmon period of Japan,
Acorns are too heavy for wind dispersal, so they require acorns were harvested, peeled and soaked in natural or
other ways to spread. Oaks therefore depend on biologi- artificial ponds for several days to remove tannins, then
cal seed dispersal agents to move the acorns beyond the processed to make acorn cakes.[citation needed] In ancient
mother tree and into a suitable area for germination (in- Iberia they were a staple food, according to Strabo. De-
cluding access to adequate water, sunlight and soil nu- spite this history, acorn is currently not a significant
source of calories for modern societies. Mush made with
2
From Wikipedia, the free encyclopedia Acorn
acorn meal is bland and unappetizing to modern tastes.
However, if properly prepared by selecting fresh, or
frozen, acorns that are not infested by insects; hulling
and peeling them; grinding them, leaching out the col-
ored tannin in fresh running water, or hot water; then
using the meal or drying it for later use, acorn meal may
be used in many recipes as a substitute for flour or other
ingredients. Generally only a half or a third of the
amount of the original ingredient should be replaced
with acorn meal. Leaching acorn meal or flour requires a
cloth bag or other filter.[10] It has been pointed out that
immersing a bag of acorn meal in a clean toilet tank is
the functional equivalent of a cold running stream. Com-
pletion of leaching can be monitored by the color of the
waste water. When it is clear the process is complete.
Varieties of oak vary in the amount of tannin in their
acorns. Varieties preferred by American Indians such as
Quercus kelloggii (California black oak) may be easier to
prepare or more palatable.[11]
Mortar holes for pounding acorns into flour, Lost Lake, Califor-
nia
Unlike many other plant foods, acorns do not need
to be eaten or processed right away, but may be stored
for a long time, as done by squirrels. In years that oaks
produced many acorns, Native Americans sometimes col-
lected enough acorns to store for two years as insurance
against poor acorn production years.
After drying them in the sun to discourage mold and
germination, women took acorns back to their villages
Dotorimuk muchim (??????), a Korean dish made with acorn
and cached them in hollow trees or structures on poles,
starch
to keep them safe from mice and squirrels. The stored
acorns could then be used when needed, particularly
In Korea, an edible jelly named dotorimuk is made
during the winter when other resources were scarce.
from acorns, and dotori guksu are Korean noodles made
Those acorns that germinated in the fall were shelled
from acorn flour or starch. In the 17th century, a juice ex-
and pulverized before those that germinate in spring. Be-
tracted from acorns was administered to habitual drunk-
cause of their high fat content, stored acorns can become
ards to cure them of their condition or else to give them
rancid. Molds may also grow on them.
the strength to resist another bout of drinking.[citation
needed] Native North Americans took an active and sophis-
ticated role in managing acorn resources by using fire,
In Germany acorns were one of several ingredients of
which increased the production of acorns and made
Ersatz coffee during the Second World War.
them easier to collect.[citation needed] The light ground fires
killed the larvae of acorn moths and acorn weevils by
Use and management by Native Ameri-
burning them during their dormancy period in the soil.
cans The pests can infest and consume more than 95% of an
oak’s acorns.
Acorns were a traditional food of many indigenous Fires also released the nutrients bound in dead leaves
peoples of North America, but served an especially im- and other plant debris into the soil, thus fertilizing oak
portant role for Californian Native Americans, where the trees while clearing the ground to make acorn collection
ranges of several species of oaks overlap, increasing the easier. Most North American oaks tolerate light fires, es-
reliability of the resource.[12] pecially when consistent burning has eliminated woody
fuel accumulation around their trunks. Consistent burn-
3
From Wikipedia, the free encyclopedia Acorn
ing encouraged oak growth at the expense of other trees The acorn is the symbol for the National Trails of England
less tolerant of fire, thus keeping oaks dominant in the and Wales, and is used for the waymarks on these
landscapes. paths.[13] The acorn, specifically that of the white oak, is
Oaks produce more acorns when they are not too also present in the symbol for the University of Connecti-
close to other oaks and thus competing with them for cut.[14]
sunlight, water and soil nutrients. The fires tended to
eliminate the more vulnerable young oaks and leave old
oaks which created open oak savannas with trees ideally
See also
spaced to maximize acorn production. • Knopper gall
In art References
A motif in Roman architecture and popular in Celtic and
[1] Plumb, Timothy R., ed (1980). Proceedings of the
Scandinavian art, the symbol is used as an ornament on
symposium on the ecology, management, and utilization
cutlery, jewelry, furniture, and appears on finials at
of California oaks, June 26-28. USDA Forest Service
Westminster Abbey. The Gothic name akran had the
General Technical Report PSW-044. pp. 1 to 368.
sense of "fruit of the unenclosed land". The word was ap-
http://www.fs.fed.us/psw/publications/
plied to the most important forest produce, that of the
documents/psw_gtr044/psw_gtr044.pdf. "The
oak. Chaucer spoke of "achornes of okes" in the 14th
symposium, held at Scripps College in Southern
century. By degrees, popular etymology connected the
California, addressed most aspects of California’s
word both with "corn" and "oak-horn", and the spelling
vast oak resource. Papers represented four major
changed accordingly.
subject categories: ecological relationships,
silviculture and management, damage factors, and
Contemporary use as symbol
products. Both scientific and applied information
was presented, including original material not
published previously. Individual topics ranged
from taxonomy and historical relationships to
management of insects and diseases. and various
oak products. In California. oaks’ value for wildlife,
recreation, watershed protection, and esthetics
exceeds their value for traditional lumber and
wood products."
[2] Richie S. King (December 2, 2011). "After Lean
Acorn Crop in Northeast, Even People May Feel the
Effects". The New York Times.
http://www.nytimes.com/2011/12/03/nyregion/
boom-and-bust-in-acorns-will-affect-many-
creatures-including-humans.html. Retrieved
December 4, 2011. "there is nothing unusual about
large fluctuations in the annual number of
acorns."
[3] Pages 276 to 291, "Mammals of California Oak
Habitats-Management Implications", Reginald H.
Barrett, author, Plumb, Timothy R., ed (1980).
Proceedings of the symposium on the ecology,
management, and utilization of California oaks, June
26-28. USDA Forest Service General Technical
Report PSW-044. pp. 1 to 368.
http://www.fs.fed.us/psw/publications/
documents/psw_gtr044/psw_gtr044.pdf.
[4] Brown, Leland R. (1979) Insects Feeding on California
Oak Treesin Proceedings of the Symposium on Multiple-
Use Management of California’s Hardwood Resources,
Timothy Plum and Norman Pillsbury (eds.).
[5] Nutrition Facts for Acorn Flour
Acorn waymark for National Trails
4
From Wikipedia, the free encyclopedia Acorn
[6] Janzen, Daniel H. (1971) Seed Predation by Animals in • Cooking With Acorns: A Major North American
Annual Review of Ecology and Systematics. Richard F. Indian Food
Johnson, Peter W. Frank and Charles Michner (eds.) • Krautwurst, Terry (September/October 1988). "A Fall
[7] NativeTech: Indigenous Food and Traditional Field Guide Nuts". Mother Earth News.
Recipes http://www.motherearthnews.com/Nature-
[8] Cooking With Acorns Community/1988-09-01/A-Fall-Field-Guide-to-
[9] Bainbridge, D. A. (November 12–14, 1986), Use of Nuts.aspx. Retrieved 20 October 2009.
acorns for food in California: past, present and future,, • Julia F. Parker and Beverly R. Ortiz, It Will Live Forever:
San Luis Obispo, CA.: Symposium on Multiple-use Traditional Yosemite Indian Acorn Preparation, Heyday
Management of California’s Hardwoods, Books, 2nd revised edition (September 1, 1996), trade
http://www.ecocomposite.org/native/ paperback, 160 pages, ISBN-10: 0930588452, ISBN-13:
UseOfAcornsForFoodInCalifornia.doc 978-0930588458
[10] Any method used to make coffee will work; throw • Proceedings of the symposium on the ecology,
the "coffee" away; keep the "grounds". Steeping management, and utilization of California oaks, June 26-28]
ground acorns in hot water then straining the USDA Forest Service General Technical Report
water through muslin is a simple method. PSW-044, Berkeley, California, 1980, edited by
[11] Pages 360 to 361, "Acorns-Food for Modern Man", Timothy R. Plumb, 368 pages
Jeanine A. Derby, author, Plumb, Timothy R., ed
(1980). Proceedings of the symposium on the ecology, The symposium, held at Scripps College in
management, and utilization of California oaks, June Southern California, addressed most aspects of
26-28. USDA Forest Service General Technical California’s vast oak resource. Papers
Report PSW-044. pp. 1 to 368. represented four major subject categories:
http://www.fs.fed.us/psw/publications/ ecological relationships, silviculture and
documents/psw_gtr044/psw_gtr044.pdf. management, damage factors, and products.
[12] Baumhoff, Martin A. (1963) Ecological Determinants of Both scientific and applied information was
Aboriginal California Populations. University of presented, including original material not
California Publications in American Archaeology published previously. Individual topics ranged
and Etnology 49(2)155-235. from taxonomy and historical relationships to
[13] "National Trail Acorn". National Trails. management of insects and diseases. and
http://www.nationaltrail.co.uk/hadrianswall/ various oak products. In California. oaks’ value
publications.asp?PageId=276. Retrieved 9 October for wildlife, recreation, watershed protection,
2010. and esthetics exceeds their value for
[14] "University of Connecticut". http://uconn.edu/. traditional lumber and wood products.
Retrieved 5 November 2010.
This article incorporates text from a publication now
External links and further in the public domain: Chisholm, Hugh, ed (1911). Ency-
reading clopædia Britannica (11th ed.). Cambridge University
Press.
• Nupa Acorn Soup (Miwokan recipe)
Retrieved from "http://en.wikipedia.org/w/index.php?title=Acorn&oldid=464115268"
Categories:
• Quercus
• Edible nuts and seeds
• Ornaments
• Native American cuisine
• Cuisine of the Western United States
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