PERENNIAL TEMPERATE FRUITS
- fruits and nuts
- eaten in all cultures, large amounts
- What is a fruit? Pericarp (endo-, meso-, and exo-) see pg. 18-20, p. 53-57
- What is a nut? Seeds, table p. 62, 70-74
- vitamins, minerals
- oils (olive, avocado)
CHAPTER 3 IN TEXT (p. 53) read pgs. 12-20
Contrast fruits with cereal grains and legumes
Economics of cultivation
Preservation drying cold storage jellies etc.
Most important Fruits
Apples - pomes - see pp. 57-64 - 50% of all fruit production
Prunus- drupes - plums (prunes), peaches, cherries, apricots
grapes - berries
Types of fruits.
The term "fruit" means different things to different people. To botanists the term means a matured
ovary along with its contents and any adhering accessory structures. Green beans, cucumbers and
squash are fruits. Tomatoes and eggplants are fruits. Fruits usually include seeds. In some
instances, however, fruit and seed development can occur without fertilization. A fruit that
develops without seed formation is called "parthenocarpic". In some cases plants that set fruit
of this type have been selected because they mature fruits spontaneously without fertilization.
Fruits are often classified by the number of ovaries which are involved in their formation, by the
position of the ovary (superior or inferior), by whether the fruit is dry or fleshy at maturity, and
by the way it releases its seeds (dehiscence).
Table 3-1, p. 54, in the text outlines this.
GO OVER THIS TABLE (pg. 54)
Simple fruits have seeds surrounded by three layers: the endocarp, mesocarp, and exocarp.
SEE FIG. 3-3, pg. 57. Simple fruits can be indehiscent or dehiscent. Dry fruits and their seeds
are usually dispersed by wind, water, or gravity. In grains or caryopses the seed coat is fused
to the ovary wall.
In other fruits, the pericarp layers are fleshy. If the fruit is produced by a single superior
ovary within a flower, the fruit is a berry. Berries may contain one or more seeds. If the
seed is enclosed in a hard endocarp, the fruit called a drupe. Citrus fruits have a special type of
berry with a leathery rind, oil glands, and specialized fleshy hairs.
If the ovary is inferior, other floral parts are attached to the ovary wall. The fruits are often
called accessory fruits. Many are still called berries. Those of the squash family are called
If there are numerous, simple, superior ovaries within a single flower, the fruit is called an
aggregate fruit, e.g., blackberries.
Multiple fruits involve fusion of many fruits from numerous separate flowers.
Composition of fruits
Fleshy fruits have evolved to attract animals that eat them and disseminate the seeds. The fleshy
part tends to consist of flavored sugar solutions without too many nutrients. The avocado and
olive are exceptions. Fruits are good sources of water soluble vitamins. See table 3-3, p. 60.
Seeds are quite different in composition. They usually have fats, oils and/or starches. They are
often protected by hard shells, seed coats, and toxic compounds. They are usually high in
nutritional energy. See table 3-4.
These fruits are preserved by drying, cold storage, as jellies, preserves or sugared, smoking or
freezing. Most are consumed raw. They are never basic to the diets of any groups of peoples, but
are important in many, especially in the Middle East, for example.
Domestication of fruits.
Although most of these crops (that is, plants related to the ancestors of most of these crops, occur
in both the Old and New World, the crop plants were almost all domesticated in the Old
World. A few New World ones have been domesticated in the last 200-300 years (e.g., the blackberry
and the cranberry). These and many other similar fruits have been used by hunter-gatherers up to
All are slow growing perennials and selection has not changed most of them significantly with the
exception of larger fruits etc.
Most are still hand harvested. Where they are grown is largely dependent on where labor is cheap.
Apples are the most important temperate fruit tree in the world. Apples and their relatives pears,
peaches, plums, cherries, strawberries, blackberries, etc. all come from the rose family, the
Rosaceae. There are several types of fruits in this family.
Apples are called "pome" fruits because of the special type of fruit they have. See page 57-64 in
The genera Malus, Pyrusand Cydoniaall belong to the same subfamily. Apples
account for 50% of the world's deciduous fruit tree production. The genus Malus probably arose in
Asia but spread to the Americas long before any human came to this continent.
All cultivated apples are native to the Old World. They probably came from the Caucasus Mtns.
Good apple cultivars are mostly cultivated by grafting. We eat the "floral cup" of the apple.
World production of fruits SEE TABLE 3-5 ON PG. 62-63.
Note that large countries almost always lead in production of plant products. They may be
relatively more important in small countries or regions of a large country however. Compare
top 5 countries and top 5 continents. Fruit crops usually require lots of inexpensive labor to be
competitive. Again look at the table.
Pears are probably the second deciduous tree fruit crop.
The pear may have arisen in sw Asia or in China or both. None are native to the New World. Pears
usually propagated by grafting. Both quinces and pears are more popular in Europe than in the U.S.
Fruits from the genus Prunus
Several important fruits belong to this genus. Among these are plums, cherries, peaches, and
apricots. The fleshy mesocarp is eaten. The fruits are drupes. Most of this group seems to have
arisen in central or western China. There are wild species of cherries and plums in the New World
These plants have been cultivated for at least 2000 years.
Prunes are dried plums. This was formerly the major method of preserving fruit. Otherwise they
would only be available in season.
Many of these plants are grown as ornamentals and not for their fruits. Peaches are the third most
important fruit crop in the U.S. (apples, oranges, peaches). They are also usually propagated by
Apricots first brought to Greece from Persia by Alexander the Great. They were brought to the New
World by the Spanish.
The "Berries" of the fruit trade
Strawberries, blackberries, raspberries are not berries. Most of the strawberry is the receptacle on
which the ovaries are born. Strawberries native to both the Old and New World.
Fragaria virginianain eastern North America most common. F. chiloensisfrom Chile.
These two species hybridized in a botanic garden in Europe about 1750 to produce the commonly
cultivated strawberry today (F.ananassa).
Members of the genus Rubus are also native to both the Old and New World. Representatives of both
Currants and gooseberries
Both Ribes(Grossulariaceae). Much more common in Europe than here. Occur in both New and
Blueberries and cranberries
Both belong to the genus Vaccinium(Ericaceae). This group native to North America and
introduced into Europe.
One of the most important fruit crops in the world. Will be discussed as a source of alcoholic
beverages later. Vitis vinifera(Vitaceae) is the most commonly cultivated species.
Many table grapes produce poor wine and different grape cultivars are usually used for beverage
The most important New World grape is V.lambrusca. Concord and Catawba grapes belong to
Raisins are dried grapes. Again, this was formerly one of the major ways of preserving fruits.
Fossils of grapes known from Europe. They were cultivated by 5000 B.C. in India and in S.E. Europe.
In North America they were widely eaten by the Indians (but not cultivated). Disease problems will
be discussed later. Grape production in California is highly mechanized.
Olives have been an important food and source of oil for more than 5000 years. Olea europaea
(Oleaceae) is native to the area at the east end of the Mediterranean Sea. They still grow wild
there. Olive seeds have been found back as far as 3000 B.C. Fresh olives are extremely bitter and
must be detoxified.
Olives processed by drying, salting, and pickling. Only about 1-2% of the olive crop is eaten as a
One seeded, indehiscent fruit, usually quite hard. In the botanical sense, acorns and hazelnuts
are true nuts. Typically high in protein and lipid. Usually hand harvested. Domestication - also
slow growing and frequently vegetative reproduction. Used in all cultures, but not major in any
today. Many nut crops are grown on arid, agriculturally marginal lands where labor is cheap.
The major nut crops are: walnut (English), almond, and cashew (discussed under next topic).
Ranking should consider both tonnage and dollar value.
From the archaeological record, it is clear that many nuts were eaten in the past. Acorns and
hickory nuts were the major food plants of many American Indian groups of the eastern U.S. and also
of California along the west coast.
Acorns are still used as a food by poor people along the Mediterranean in Europe.
Walnuts, pecans, almonds, chestnuts, filberts or hazel nuts are native to temperate regions of the
world. Pecans are the only nut to come from the New World. Peanuts are native to the South
American non-center (discussed under legumes). In contrast to the fruits above, nuts are dry
fruits. In addition, the edible portion is the embryo which has enlarged cotyledons. See table
3.4, p. 60, for nutritional information.
Pecans and walnuts
The English walnut (Juglans regia, Juglandaceae) (native to Iran) is the most important of
these. In the United States, most walnuts are grown in California. Rich in oil.
The pecan (Carya illinoensis) is native to North America. Native to south central U.S. and
Mexico. "Paper shell" varieties now often cultivated. Pecan orchards common in the south, e.g.,
in Texas, Oklahoma, Georgia etc. Some in Australia and S. Africa.
The black walnut (Juglans nigra) is also native to North America, but is relatively
Hickory nuts (Caryaspp.) belong to the same family. They were formerly eaten by many North
American Indians, but are relatively unimportant today.
Almonds (Prunus amygdalus, Rosaceae) belong to the same genus as the fruit crops we just
discussed. The removal of the leathery mesocarp leaves the seed inside the endocarp. The seeds
of some cultivars are highly toxic. Sweet and bitter almonds. Almonds were cultivated as an
oilseed crop and later became a nut crop.
In the U.S., they are mostly grown in California. We can grow almonds competitively because of
mechanization. Mediterranean, Australia, S. Africa etc. High in protein.
Today most come from Europe (Castanea sativa, Fagaceae) and Japan and China (C.
crenata). The chestnut blight wiped out the American chestnut (Castanea dentata)
about 1900-1930. Chestnuts are extremely popular in Europe and in Asia.
Hazel nuts (Corylus avellana, Corylaceae) are native to the Old World. This is the common
cultivated species. Other Corylusspecies occur in the New World however, e.g., Corylus
americana. They are also much more popular in Europe than here. In the U.S., most come from
Oregon (about 95%). High in oil.
Pistachios (Pistachia vera) come from the poison ivy family -- the Anacardiaceae. These nuts
are native to the near east and central Asia. They have been cultivated for over 3000 years.
Turkey, Iran, Afghanistan, India major producers. The "nut" is the seed enclosed by the endocarp.
The pulpy part is removed before marketing. The "nuts" are often dyed red. High in protein.
Miscellaneous temperate nuts.
Piñon from Pinusspp. Important in the S.W. U.S. and Mexico. Other species important
to Near East.
Ginkgo bilobaseeds are eaten in the orient after fermenting off the outside portion. They are
then boiled or roasted. Supposedly poisonous if not.
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Revised February 2005
© David S. Seigler, Integrative Biology 363, Plants and Their Uses,
Department of Plant Biology, 265 Morrill Hall, 505 S. Goodwin Ave., University of Illinois, Urbana,
Illinois 61801, USA. 217-333-7577. email@example.com.