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Legumes rank next in importance to
cereals as human food sources. They
contain more protein than any other vegetable and thus are akin to animal
meat in food value. Fats and carbohydrates
are also present. The proteins occur
as small granules in the same cells with the starch grains. The high protein content is related to the
presence on the roots of many legumes tubercles that hold nitrogen-fixing
bacteria. These bacteria are able to
convert atmospheric nitrogen into nitrates.
This augments the nitrogenous material available for the plants. The legumes belong to the family
Leguminosae, which is noted for having a special kind of fruit, a legume,
which is a pod that opens along two sutures when the seeds are ripe. Over 11,000 species of legumes are known,
and many are of importance as industrial, medicinal or food plants. They have been cultivated and used for
food for centuries worldwide. The
seeds are of greatest importance. As
is the case with other dry seeds, the low water content and impervious seed
coats enhance their value for long-term storage and increase their
longevity. Legumes are easy to grow,
they mature rapidly and they are highly nutritious. Not only are proteins abundant but also they possess minerals
and vitamin B. They are absolutely
essential in a vegetarian diet.
Before the discovery of potatoes, they constituted a greater part of
the food in Europe. Legumes have a
high-energy content and are particularly well suited for use in cold weather
or where physical exertion is pronounced.
The immature fruits also serve as food as demonstrated by garden beans
and peas. Because all parts of the plant are
rich in protein, legumes are valuable as field and forage crops. When plowed under they are an excellent
fertilizer and greatly increase the nitrogenous content of soil. The Common pea, Pisum sativum, is native to Southern
Europe and has been cultivated since before the Christian era. Peas were well known to the Romans and
Greeks. However, it wasn’t until the
middle of the 17th Century that production became more widespread in
Europe. The earliest colonists
brought peas to America. Peas are
annual, glaucous; tendril bearing, climbing or trailing plants, with white or
colored flowers and pendulous pods.
Although originating in warm regions they thrive where there is a cool
summer and abundant moisture. In
Mediterranean climates they thrive during winter and spring months.
The gray pea of Greece and the Levant is thought to have given rise to
Field Peas. They have colored flowers
and angular colored seeds and are very hardy, withstanding frost and
altitudes up to 8,000 ft. Field peas
are grown for seed that is used for human consumption in the form of pea meal
or split peas. They are also an
excellent grain for livestock. The
plants are sued for forage, silage and green manuring.
Garden peas have white flowers and round smooth or wrinkled seeds that
are yellow or white in color. They
contain more sugar than field peas and the seeds are eaten green or are used
for canning. For canning peas are
usually harvested with a mowing machine.
Pea-cannery refuse is a valuable livestock feed. In some varieties the pods are fleshy and
crisp and are consumed as well as the seeds. Garden peas wee used by Gregor Mendel in his experiments in
plant genetics. Chickpeas (Garbanzo Beans) Chickpeas, Cicer arietinum, are native to
southern Europe where they are still extensively grown. They are an important food in many parts of
Africa, Asia and Central America.
India has grown an amount that is equal to the sugar cane acreage of
the whole world. The plant is a
branching, bushy annual, which mature in 90 days. It is well adapted to arid and semiarid regions. Chickpeas are the best legumes for human
consumption as the seeds are very nutritious. The early Egyptians, Hebrews and Greeks grew them. The sparse foliage is poisonous so the
plant cannot be used for forage. The
green pods are infrequently consumed and the seeds are used as a substitute
for and as an adulterant of coffee. Cowpeas, Vigna sinensis, are more closely
related to beans than to peas. They
are vigorous bushy or trailing summer annuals with curious, cylindrical
pendant pods. The plant continues to
grow if environmental conditions are suitable. The cowpea is a very old crop, probably originating in Central
Asia, although it has been grown in Southeastern Asia for over 2,000 years. It was introduced into the tropics and
subtropics of the world, reaching the West Indies in the 17th Century and
North America in the 18th Century.
The seeds are used as feed for poultry and cattle, and they may serve
as a coffee substitute. The main
value is as a forage crop, as a cover crop to prevent erosion and as a green
manure. Cowpeas are important in
India, China and the southern United States.
It is susceptible to frost and is confined to warm humid areas in a
sandy or loamy soil. This is a Pigeon pea, Cajanus cajan, that was first
domesticated in Asia or Africa and is now widely cultivated in the tropics
and subtropics, especially in the East Indies, the West Indies and
India. There are many varieties. The plant is an erect shrub. Both the immature and mature seeds have
been used for human and animal food for thousands of years. In modern times it has been developed as a
forage crop and rivals alfalfa in importance. It is drought resistant, grows well in any kind of soil,
matures rapidly and in other ways is highly desirable. Beans
Garden, Pinto or Kidney
beans, Phaseolus
vulgaris,
are indigenous to America. They were
probably domesticated by the Incas and were early used by the Amerindians of
both South and North America. In
modern times the young pods (string or snap beans), the unripe seeds (shell
beans) and the dried ripe seeds are all used for human consumption. The whole plant is used for forage. Beans are low, erect or twining annuals
with small white or colored flowers, trifoliate leaves and slender pods. They are grown as either bush or pole
beans and over 1,000 varieties are cultivated. Both groups have green-podded and wax-podded varieties. The commercial dried bean is of more
recent origin. It was first grown in
1836 in New York State. Much of the
bean crop is canned. Even though
beans will grow on a variety of soils, a fertile soil, rich in lime, is
required for a good yield. A warmer
climate than for peas is desirable, and crop rotation should be
practiced. On large farms machines harvest
the crop and the beans are dried, stored and threshed before marketing. Dried pinto beans must be cooked without
salt or additives until they are soft, after which condiments such as
peppers, tomato, salt, soy, molasses, etc. may be added. The
culls are fed to livestock and the straw is used for forage. Presently these beans are grown worldwide. Lima beans, Phaseolus limensis, are native to Peru
and Brazil and have been grown in South America for centuries. Originally a perennial they are usually
treated as annuals. Lima beans
require warmer weather and higher humidity than Garden Beans. The original types were pole beans, the
bush limas arising later as mutations.
Either green or dried beans are consumed and a large quantity is
processed. In addition to the large
variety there is a smaller form, the Sieva Bean (Phaseolus lunatus), also native to
tropical America. An excellent crop
of Lima beans was produced in coastal Southern California until the land was
diverted to housing development. Other species of Phaseolus that are often
cultivated include the Scarlet Runner Beans, P. coccineus that have a thickened
root and ornamental flowers and the Mung Bean, P. aureus. Mung beans were grown in India in ancient
times and are still an important crop.
The small oval seeds are highly nutritious and the green pods are also
consumed. There are over 100
varieties grown in China and other parts of Asia. The Mung Bean is grown in North America principally as a forage
plant. The Adsuki
Bean, P. angularis, is next to the Mung
Bean in importance in Manchuria and China; and the Rice
Bean, P. calcaratus, is widely cultivated
in Southern Asia. Soybeans Soybeans, Glycine max, are small, bushy,
erect or prostrate annual plants that resemble the cowpea. The crop is much easier to handle for it
does not become tangled, matures earlier and has a higher yield, produces a
better seed and can be threshed. The
seeds all mature at the same time.
The soybean is one of the oldest cultivated crops. It was grown in China centuries before the
first written records in 2,838 B.C.
It is indigenous to Southeastern Asia, where over 1,000 varieties are
grown. Manchuria has led commercial
production, followed by Korea, Japan, China, Indonesia and North & South
America. Soybean is the most
important legume in Asia there it is consumed fresh, fermented or dried and
is used everywhere in the daily diet to supplement rice. The seed is the richest natural vegetable
food known. In tropical areas,
especially Indonesia, soybeans are boiled and then fermented by addition of a
mold to yield a food known as Tempe. Soybean sauce, made from cooked beans,
roasted wheat flour, salt and ferment, is widely used. The flour, with a low carbohydrate and
high protein content, is an excellent food for diabetics. Soybean milk, extracted from the seed, is
used in cooking and is used as a substitute for cow’s milk. Soybean sprouts are a favorite food in the
Asian diet. Although soybean oil has
been extensively used commercially for frying and in margarines, research in
2019 has associated the development of autism with this oil. The soybean has ever increasing
other uses worldwide. It is an
important aid to agriculture, a valuable commercial crop, a good livestock
food and the source of numerous raw materials for use in industry. Soybean oil is an important drying
oil. Soybean protein is extensively
used to produce the foam liquid used for extinguishing oil fires and as the
source of a synthetic fiber, similar to casein fibers. Ever since the 1930’s soybean has
assumed a position of great importance in the agriculture of the United
States. It is of greatest importance
in the North Central states, with Illinois producing over 40 percent of the
total crop. Soybeans are grown for
hay, silage, and green manure, as well as for the seeds, and hundreds of varieties
are known. It can be grown under a
variety of soil and moisture conditions but requires a rather warm
temperature and is susceptible to frost. Broad Bean, Vicia faba, is also called the Windsor
Bean, Horse Bean or Scotch Bean. It is grown as a forage crop as well as
for the seeds that furnish food for both humans and livestock. The plant is a strong erect annual, 2-4
feet tall, with flat pods and large seeds.
It was cultivated in prehistoric times and most likely is indigenous
to Southwestern Asia or Algeria. Over
100 varieties have been grown, mainly in the Old World. The broad bean was the only edible bean
known in Europe before the voyages of Columbus to America. It is an important crop in England. Its growth is encumbered by dry hot
summers and thus is not a preferred crop in most of the United States. It is sometimes used as a cover crop, in
crop rotation and for livestock fodder and silage as well as for the seeds. Horse or Jack Beans, Canavalia ensiformis, are indigenous in the West Indies and are
now grown in almost all tropical countries for their seeds. The plants are bushy annuals with long
sword-shaped pods that may contain as many as 12 large beans. The unripe seeds and pods are used for
human food and the whole plant serves for green forage. The plants are hardy, drought-resistant
and immune to most pests. They are
grown extensively in the southern United States. Velvet beans, Stizolobium deeringianum, are widely cultivated
in the tropics for their edible seeds and for fodder. The plant is an annual herbaceous climber
that exceeds most other legumes in the rapidity and extent of growth. It has been of some importance in the
Southeastern United States. Peanuts, or Groundnuts, Arachis hypogaea, are true legumes rather than nuts because the shuck is
merely a shell-like pod. The plant is
a bushy or creeping annual with the strange habit of ripening the fruit
underground. The peanut is indigenous
in South America but was early carried to the Old World tropics by the
Portuguese explorers and is now grown extensively in most tropical
countries. It was brought to Virginia
from Africa and is now one of the most important crops in the Southeastern
United States. There are over 20
different kinds of peanuts grown that differ in habit and the size of the
pod. The cultivation of peanuts is
quite complex. They require ample
warm sunshine and a moderate rainfall and can be grown successfully only
south of 36 deg. North latitude. A
sandy soil is preferred, although any but a low soil can be used. The soil must be friable so that the
ripening fruit can be buried and it must be well fertilized. During harvest the rows are plowed and the
plants are lifted out with forks, shocked and capped for cure. Later the fruits are removed, cleaned and
polished. The plants may be used for
forage, livestock feed or as soil renovators. The nuts or seeds are used for roasting or salting. In candy and for the preparation of peanut
butter. For the latter the seed coats
and embryo are removed and the nuts are roasted either dry or in oil, and are
then ground to a paste. Peanuts are
very nutritious. One pound yields
2,700 calories whereas one pound of beef furnishes only 900 calories. Nevertheless, some are allergic to peanuts
and must take precautions to avoid ingesting peanuts or their
derivatives. Peanut oil is important
food oil. The oil cake is fed to
livestock. The protein contained in
the nuts has been used in the manufacture of Ardil, a
synthetic fiber. Research beginning
in 2019 has developed a procedure to overcome peanut allergies. Lentils, Lens culinaris, are some of the most
ancient of foods and also one of the most nutritious. The ancestral home is Southwestern Asia,
but they were introduced into ancient Egypt and Greece. Lentils are often mentioned in the
Bible. The plant is a slender,
tufted, many-branched annual with tendrils.
The pods are short and broad, with small lens-shaped seeds. The seeds are used principally in soups
and in East Indian cuisine mixed with rice and herbs. They are easy to digest, more so than
meat. These are produced in colors
that vary from gray to tan and red.
The plants have been used for fodder.
When prepared as split-pea soup, the addition of vinegar and sugar
enhances the flavor. Lablab, Dolichos lablab, is a bean-like legume
that is grown in many tropical areas.
The plant is usually a woody climber with a high yield of pods that
continue to bear over several years, but that may also be grown as an annual.
Both the pods and the seeds are
consumed, and the entire plant is used for hay and forage for horses and
cattle. The need for forage crops arose
with the domestication of animals.
Initially wild grasses probably were used, but other sources were then
sought. These gradually became more
numerous and more varied. Today the
extensive cultivation of grasses and legumes as forage crops is principally
the product of European and American civilizations. In addition to various cereal grasses and food legumes, many
other species have been grown entirely as forage crops with little or no
value as human food. Included are
such grasses as Timothy, Phleum
pratense,
Orchard Grass, Dactylis glomerata, Redtop,
Agrostis
alba, Brom Grass, Bromus inermis, Johnson Grass, Sorghum halepense, Tunis
Grass, Sorghum virgatum, and Sudan Grass, Sorghum vulgare var. sudanense. Alfalfa, Medicago sativa, native to
Southwestern Asia, may have been the first cultivated forage plant. it was known to the Greeks, Romans and
Persians. It was introduced into
China and Europe and reached North America during the European
colonization. Alfalfa has become the
most important forage crop grown in the United States and many new varieties
were developed. It is especially
abundant in Middle Western and Western states. Alfalfa is useful for pasture, hay and silage and for improving
the soil. Dehydrated alfalfa or
alfalfa mean is also used, and alfalfa sprouts are used for human food. Other species of Medicago include Bur
Clover,
M.
hispida
and Medic,
M.
lupulina. Clover, Trifolium spp., is grown
particularly in the Northeastern and North Central united States. It is valuable in crop rotation and is
often grown in mixtures with forage grasses.
Important species are Red Clover, Trifolium pratense, Alsike
Clover, T.
hybridum,
Ladino or
White Clover, T. repens, and Crimson
Clover, T.
incarnatum. Sweet clovers, Melilotus spp., have become important
forage crops since the beginning of the 20th Century. They are especially valuable for pastures
and for soil improvement. Most
production is centered in the Corn Belt of the United States. Both White Sweet Clover, Melilotus alba, and Yellow Sweet Clover, M. officinalis, are grown. Kudzu Bean, Pueraria lobata, is a drought-tolerant
perennial legume indigenous to Japan and Eastern Asia. It was introduced into the Southeastern
United States in the middle 20th Century.
The plant has a long tap root and produces runners of 50-100 feet in
length. Kudzu yields good hay and
forage and was important in erosion control.
The pods can be used and a valuable starch is obtained form the large
roots. Gradually kudzu escaped into
the countryside and has begun to smother native vegetation. By the 21st Century it had attained a pest
status of very grave concern as few efforts to eradicate it or to reduce its
abundance have succeeded. Three species of Lespedeza of some
importance in the Southeastern United States are the annual Common Lespedeza, Lespedeza striata, a Korean species, L. stipulacea and a perennial from
China, L.
cuneata. These are beneficial to soil conservation
and for renewing exhausted soils.
They furnish excellent hay and pasturage.
There are a number of Vicia spp, both native and
introduced, that are used for forage, especially in the coastal areas of the
United States. Two species of
importance are Common Vetch, Vicia
sativa,
and Hairy Vetch, V. villosa. They are mostly
weak-stemmed, viny annuals that are useful for cover, green manure and soil
improvement as well as for hay, pasture and silage. Livestock find them very palatable. They are frequently grown in mixture with small cereal grains.
Tree legumes have come into prominence as replacements for cereal
grasses on eroded soils. A few
species are excellent substitutes for maize, wheat and other cereals in
livestock feeding. Some of the more
important tree legumes are the following: Mesquite, also known as Algaroba
and Keawe, Prosopis juliflora, is native to the West
Indies, Central America and Mexico.
The introduction of a single tree into Hawaii was followed by a spread
to the drier climatic zones of all the islands. It is considered a desirable species on the islands. The flowers are a source of honey and the
pods and ground seeds are important livestock feed. Mesquite gives an enormous yield of 2-10 tons per acre
depending on the local rainfall. It
has been estimated that one acre of mesquite can produce 1,600 lbs. of beef,
while one acre of corn or alfalfa produces only 450 lbs. Mesquite trees grow rapidly, are
drought-tolerant and can utilize arid, barren ground where other crops will
not grow. Cultivation of Mesquite has
extended to other parts of the world with similar climate. Another species, Prosopis glandulosa, is better adapted to
colder climates. The Carob tree, Ceratonia siliqua, in Syria and probably
native to southern Africa, has been cultivated since ancient times in other
Mediterranean countries. Carob was
the “locusts” that were the food of John the Baptist and the Prodigal
Son of the Bible (Hill 1952).
The large pods have served as livestock feed for ages. The tree is a small evergreen with glossy
green foliage. It blooms in autumn and
carries the young fruit until late the following summer. It does best in rocky dry soil. Carob trees give a very high yield of
pods. These contain 50 percent sugar
and are often consumed directly in the dried state. The ground seeds yield a highly nutritious meal that can be
added to bread. The pods contain a
valuable gum known as Tragasol. Although a handsome tree, the bloom gives
an obnoxious odor and the numerous pods falling to the ground are a messy
problem in the urban setting.
Honey locust, Gleditsia
triacanthos,
is indigenous to the humid eastern North America in areas of hot summers and
cold winters. The pods contain 29
percent sugar and are readily eaten by livestock. Honey locust is also a valuable ornamental and timber tree. Many other tree legumes are of
some importance in world argriculture.
There is another Mesquite, Prosopis
glandulosa,
a spiny shrub of the arid southwestern deserts of North America. It has pulpy pods that have long served as
food for humans and livestock. The Rain
Tree, Samanea saman, a huge tropical
American tree, bears curved black pods that are filled with sweet pulp and
which is an excellent livestock feed.
The Nittas, Parkia
biglobosa
and P. filicoidea, of West Africa have
large pods with 31 percent sugar content.
The seeds yield a very nutritious flour with 36 percent protein, 23
percent fat, 15 percent starch and over 12 percent sugar. They are widely used by the natives when
traveling as they constitute a concentrated natural ration. In other parts of tropical America Inga
edulis and other species of the genus are cultivated for their pods,
which have a sweet and agreeable pulp, and as shade trees in coffee
plantations.
The term “nut” is used loosely to describe a number of related or
unrelated plant structures.
Officially a nut is a one-celled, one-seeded dry fruit with a hard
pericarp or shell. Some of the
so-called nuts of commerce correspond to this description. Among them are the acorn, filbert,
chestnut and hazelnut. The others may
be seeds, as the Brazil nut; legumes, such as the peanut; or dry drupes from
which the outer parts of the fruit have been removed, such as the almond,
coconut, pecan and walnut. The
following discussion will group all of these together regardless of their
morphological nature. They will be
classified according to their fat, protein and carbohydrate contents. The Brazil-nut tree, Bertholletia excelsa, is a giant with a
rough bark in the Amazon forests in South America. It bears 18-24 hard, brown, spherical, woody fruits from 4-6
inches in diameter and weighing 2-4 pounds.
Each fruit contains 12-24 seeds with a hard bony covering. These are the Brazil nuts of commerce,
also called Cream Nuts. They have served as human food for centuries. The food value is very high with a fat
content of 65-70 percent and protein content of 17 percent. Collection and shipping of these nuts is
an important industry in South America.
Trees are rarely cultivated and most of the output is obtained from
the wild trees. There are also
similar nuts of finer quality and more delicate flavor obtained from the Sapucaia
or Paradise-nut trees, Lecythis usitata, Zabucajo sp., and other species. The Cashew nut tree, Anacardium occidentale, is a handsome native
of Brazil that is now extensively cultivated in tropical countries from
Mexico to Peru and Brazil, in the West Indies, southern Florida and the
Mediterranean area, Mozambique, India, and the East Indies. It bears a thin-skinned, pear-shaped,
yellow or reddish, juicy “fruit” known as the Cashew
Apple. This is actually the
swollen peduncle and disk. The true
fruit, a small curved or kidney-shaped structure, is borne on the outside of
the “apple” at the distal end. This
is the cashew “nut.” The rich kernel is delicately flavored and contains
nutritious oil. The grayish-brown
coat, or shell, contains oil that blisters the skin. The ripe fruit, which as a characteristic
aroma, is consumed in many countries or used for preserves. The fermented juice makes a wine, Kaju
that is sometimes bottled. The
leaves, the light close-grained wood, the sap and the bark are also useful. This is one of the most important
economic plants especially in the South Pacific and other tropical
areas. Coconut is a palm, Cocos nucifera, probably native to
the Malay archipelago, but possibly of Ecuadorian and Central American
origin. It grows best near the
seashore, but can occur at altitudes of 5,000 ft. It is undoubtedly one of the most graceful and beautiful of all
palms, often with a typical leaning habit.
The bases of the slender trunks are swollen. The large pinnate leaves are 6-12 ft. long and 18 in.
wide. They are borne in a cluster at
the top of the stem. The flowers are
formed in a large compound spadix, enclosed by a spathe. The fruit is a 3-sided dry drupe. It consists of a smooth rind, or exocarp;
a reddish-brown fibrous mesocarp; and a hard stony endocarp, or shell that
encloses the seed. The white meat and
milk represent the endosperm of the seed; the embryo is embedded in the hard
endosperm. The coconut plants have many
uses. The leaves are highly
incendiary that when burned produce a bed of coals, which imparts a delicious
flavor to grilled meats. The fibrous husk yields Coir, a
textile fiber. The hard shell, or
endocarp, is used for fuel, vessels and other containers, and a fine grade of
charcoal. The water of the green
coconut makes an agreeable and refreshing drink. The meat may be eaten raw or shredded and dried to form
desiccated coconut. It is frequently
ground and pressed through a cloth after water has been added. The resulting coconut milk is very
palatable and a good substitute for cow’s milk as it contains several
vitamins. However, the main use of
the meat is for copra, the source of coconut oil and oil cake. The unopened inflorescences yield a sweet
liquid that is converted into palm sugar or fermented to make palm wine, arrack,
or vinegar. The leaves are also used
for thatching, baskets, hats, mats and curtains. The petioles and midribs are used for fence posts, canes,
brooms, needles and pins. The trunk
furnishes a strong, durable wood for houses and bridges. Some of the porcupine wood of commerce,
much used for cabinetwork, is from the coconut. The heart of bud at the apex of the stem is used in salads or
is cooked. The bark contains a resin
and the roots a drug. Coconuts thrive best within the
true tropics, but they will grow at higher latitudes. They grow best in fertile soils. Wild trees are an important source of
coconuts, but commercial plantations abound.
Mature nuts are planted in a nursery and barely covered. They germinate in a few months and the
seedlings are transplanted when about a year old. Proper spacing, clean cultivation and intercropping improve
growth. Cover crops, fertilization
and irrigation also help to maintain the yield. Flowering and fruiting at tropical latitudes are continuous and
ripe nuts can be obtained during every month of the year. Harvest is usually every two months. The yield and size of the nuts vary with
the spacing and the variety planted.
About 3,000-7,000 nuts are required to produce one ton of copra, which
yields 1,200 lbs. of coconut oil and 800 lbs. of oil cake. One thousand nuts can yield 165 lbs. of
coir fiber. Great care must be taken
not to lie beneath the trees, as the fruit is very heavy and can cause grave
injury when falling. Driving them against a sharp spike
fastened to a piece of wood and wrenching them apart husk the coconuts. An experienced person can husk 1,200-2,500
nuts per day. The nuts are broken into
two halves with a blow of a heavy dull knife. The dried meat or copra, the most important product, is
prepared in different ways. About
half the supply is dried by simple methods, using the sun or drying on racks
over fires made from coconut shells.
After a few days the meat curls away from the shell and can readily be
detached. Copra prepared in this way
is dark colored and has an oil content of about 50 percent. Plantation copra is dried within 24 hours
in the sun followed by heat from fires in drying houses. This copra is white and has a high oil
content (60-65 percent). The best
grade of copra has traditionally come from Sri Lanka. Desiccated coconut is used by
confectionery and candy makers and in cooking. It is prepared from the best grade of nuts. These are cured for several weeks and then
carefully cracked and the meat is removed while fresh. This is washed and cut into threads and
dried in a vacuum for one hour at 160 deg. Fahrenheit. Hazelnuts, Corylus spp., are found in cool
temperate regions of both hemispheres.
The native American shrubs, Corylus americana and C. cornuta, produce small
nutritious and palatable nuts of no commercial importance. Larger European species, C. avellana and C. maxima, are the source of Filberts, Cob Nuts and Barcelona Nuts.
Filberts are cultivated in Southern Europe and Oregon. Wild filberts have been grown successfully
in West-Central Wisconsin, but were eliminated by Power Companies when considered
a threat to the lines, even though the plants never reached more than one
meter in height due to freezing temperatures in winter. Hickories, Carya spp., are native American
trees common throughout the eastern deciduous forest. Butternut hickories contain a large amount
of tannin and are not suitable for food but are eaten by livestock. Another group has sweetish edible nuts,
the best of these being the Shagbark Hickory, Carya ovata and Shellbark
Hickory,
Carya
laciniosa. These can be some of the finest of the
wild nuts in North America and they have excellent storage qualities. The trees show promise under selection and
experimentation. They can be grafted
and crossed and many new varieties adapted to a wide range of soil and
climatic conditions have been produced.
The nuts yield a fine salad oil and the wood is a valuable timber. The bark, which frequently sloughs off, is
used in smoking meats. Macadamia trees, Macadamia ternifolia, are native to
northeastern Australia. They produce
a nut also known as Queensland Nuts. The tree has been introduced into other
subtropical areas of both hemispheres.
It has become of considerable commercial importance in Hawaii. Both thin-shelled and thick-shelled
varieties are grown. The kernels have
a sweet flavor that is enhanced by roasting in a rich oil. Hard shell varieties are very difficult to
break open. Hard-shelled varieties
are extremely difficult to break open. The Pecan Tree, Carya illinoensis, is indigenous to the
southeastern United States and northeastern Mexico. It is in the same genus as Hickory. The trees are extensively cultivated in both the Southern
states and points west all the way to California, in the latter under
irrigation. New varieties have
extended the production northward into the upper Mississippi valley, Indiana
and Virginia. Harvesting begins when
trees are only 3-4 years of age. Paper-shelled
varieties have been developed from East Texas stock. Pecans have a high fat content of 70% and
they are used in desserts, candy, ice cream, cakes, etc. Pralines, consisting
of brown sugar, vinegar and nuts, are a favorite confection in the South. Pecan pie is a delicious blend of nuts
with a brown sugar custard base.
Pecan oil and tannin obtained from the shells are by-products. The seeds of Canarium ovatum, a native tree of the
Philippines are Pili Nuts. They are
very similar to Java almonds from C. commune of Eastern Asia and the
East Indies. The seeds of both are
consumed raw or after roasting. They
have a spindle shape with a very thick hard shell. Fatty oil is expressed from the seed and used for human
consumption and in oil lamps, and a resin is extracted from the tree. The plum-like fruit of the Pili is also
edible. Pine nuts or Piñons
are obtained from the seeds of several species of Pinus, native to Western
North America. Included are the Nut
Pines, P. cembroides var. edulis and P. edulis var.
monophylla; the Digger Pine, P. sabiniana; and the Torrey
Pine, P.
torreyana. These bean-sized nuts have a thin brownish-red shell and a
slightly resinous flavor. Amerindians
have always harvested piñons. The
pinecones are harvested before they would open naturally. They are then roasted so that the scales
will fall apart, which allows the seeds to separate. Wild birds and rodents quickly gather them
when they open naturally in nature.
The production is entirely from wild trees. Pignolia Nuts are the seed of Pinus pinea of
Southern Europe. These are longer and
more yellow than piñons and have a rich delicious taste. Other species of pine provide edible nuts
in India and Eastern Asia. China has
increased its export of such nuts in the latter 20th Century. Walnut trees provide both nuts and
timber. They are native trees of
North America and Europe. Black Walnut, Juglans nigra, is an abundant tree
of the eastern deciduous forest region of North America. It is a tall handsome tree that is often
used for ornamental purposes. The
large spherical fruits are green when ripe and the outer covering has to
disintegrate or be physically removed to free the nuts. The walnut kernels have high oil content
and were a favorite food of Amerindians.
They retain their flavor when cooked and have a food value four times
as great as meat. They are very
difficult to crack and the husk stains the hands a dark brown so their wild
harvest today is restricted to the very dedicated. These nuts are used mainly in the candy and ice cream
industries. The tree is very productive
and can be grown in a variety of soils and climates. Walnuts provide a valuable timber and also
a brownish-black dye that was used by early settlers to dye hair. Butternut, Juglans cinerea, is native to area
with limestone soil in eastern North America. The tree is smaller than Black Walnut with elliptical nuts that
have a deeply corrugated shell.
Butternuts are high in fat content and are often preferred to walnuts
because of their finer and richer flavor.
The kernels are more readily separated. Sugar is sometimes obtained from the sap. They have often been used in the candy
industry. English Walnut, Juglans regia, [<Photos>] is
indigenous to Iran and is widely cultivated in Southern Europe, China and
other parts of Asia. In North America
California and Oregon are leading producers.
English walnut has been under cultivation for ages and many varieties
exist. The attractive trees are
usually planted in rows. Only the
outer limbs produce perfect nuts. The
kernels are easily freed from the pericarps and are bleached and polished. The furrowed kernels are the cotyledons of
the seed, no endosperm being present.
Walnuts yield excellent oil and the oil cake is a good livestock feed. The codling moth, Carpocapsa pomonella and
Navel Orangeworm, Amyelois transitella, often attack the crop in North
America and biological agents (parasitic insects) have been partially
successful in control. Nuts with High Protein Content Almonds are probably the most
popular of the high protein nuts.
They are obtained from a medium-sized tree, Prunus amygdalus that is related to the
peach and closely resembles it in blossoms and young fruit. Almond trees are also cultivated as
ornamentals. The almond fruit is an
edible drupe, with a tough fibrous rind surrounding the stone or “shell” and
the seed or “nut.” There are two
major types of almonds. Sweet Almonds,
Prunus
amygdalus var. dulcis, have an edible seed and are the main source of the
commercial product. The tree is
native to the eastern Mediterranean where it has been cultivated for
centuries. It is grown throughout
Southern Europe and in California, Australia and South Africa. The seeds are especially delicious when
eaten green. However, they are
usually roasted or salted or made into a paste to be used for cake and
bread. An extract is also prepared
for flavoring. There are many
varieties, some with think shells and some with hard shells. Jordan almonds are hard-shelled with a
thinner integument on the seed and a finer flavor. In California a successful biological control effort against
the Navel Orangeworm, Amyelois transitella, reduced harvest losses to
below four percent. A substitute for
milk is produced from almonds. Bitter
Almonds, Prunus
amygdalus var. amara, possess a bitter glucoside, Amygdalin that
readily breaks down into prussic acid and thus prevents their use as
food. Nevertheless, they are grown in
Southern Europe as a source of the oil.
During the extraction process the prussic acid is eliminated and the
oil can then be used for flavoring.
Bitter almonds are also used as a rootstock for sweet almonds. The Beech tree, Fagus grandifolia, is abundant in the
eastern deciduous forest of North America.
The high protein nuts are small, triangular and very sweet. They are of minor importance for human food,
but are eagerly sought after by cattle, pigs, squirrels, poultry and other
birds. They impart a fine flavor to
pork, and razorback hogs are fed on the mast, which is a mixture of
beechnuts, chestnuts and acorns. The
European beech, Fagus sylvatica, yields slightly larger nuts that are
consumed by humans and used for the edible oil of beechnuts. Pistachio, Pistacia vera, also known as Green Almond, is a small tree indigenous to Western
Asia. It has been cultivated in the Mediterranean
region since before 2,000 B.C. It is
now grown in Iran, Afghanistan, the southern United States and irrigated
areas of the West, especially California.
However, the quality of irrigated nuts is considerably lower than
those produced from natural rainfall.
The fruit is a drupe. The seed
contain two large green cotyledons with a reddish covering. These high protein “nuts” are salted in
brine while still in the shell. They
are highly prized for their color and resinous flavor and are combined with
other nuts as mixed nuts and as a flavoring material for ice cream and
candy. Their quality varies with the
kind of culture. Restricting water
reduces yield be improves flavor. Nuts with High Carbohydrate Content Acorns are the fruits of oak
trees, Quercus
spp. They are true nuts. Acorns have been used in America for
fattening livestock, especially hogs.
They are an excellent human food, but are rarely used except by
indigenous people. The White oak, Quercus alba, and the Live oak, Q. virginiana, are the best of the
twelve or more species with edible fruit.
The Amerindians have always used acorn flour. They ground the nuts, leached them to
remove the tannin and other bitter qualities, pounded them into a meal and
used them in porridge, mush and other ways.
Acorns have been used in other areas of the world, for example they once
furnished 25 percent of the food of the poorer classes in Italy and Spain in
the form of acorn bread or cake. This
is highly nutritious and may be stored indefinitely. Any species of acorn is edible after the
tannin has been removed, but the Holm oak, Q. ilex, is the main source.
Oak trees are very productive and adapted to poor soil. The problem with acceptance of this food
is its unaccustomed flavor, which is probably related to few persons being
able to prepare it properly. <bot120> Southern Live Oak, Quercus virginiana.,
South Texas <bot243>Jeffrey
Pine (Pinus jeffreyi ) & California Black Oak (Quercus
kelloggii), San Bernardino Mts.,
California <bot301> Canyon Live Oak (Quercus chrysolepis),
Palomar Mts., California <bot375> California Black Oak (Quercus kelloggii),
San Bernardino Mts., California Chestnuts, Castanea spp., are found in the
eastern United States, Japan and Europe.
The American species, Castanea dentata, was once very abundant in the deciduous forest region. It was a handsome tree and furnished
valuable timber as well as excellent quality nuts. These served as food, either raw or roasted, for over 200
years. Chestnut blight disease has
about eradicated this tree from America, with no fruiting observed since the
middle of the 20th Century. Research
to restore fruiting trees has begun in the 21st Century. The European chestnut, C. sativa, with
larger fruits has been extensively cultivated in Southern Europe for
centuries and hundreds of varieties have been established. The nuts or marrons as they are called,
are a standard food and are as important as wheat maize in America. They are grown everywhere, often on dry
hillsides that are unfit for other purposes.
The nuts are consumed raw or are roasted, boiled or used for stuffing
or flour. The Japanese chestnut, C. crenata, is immune to chestnut
blight and has been introduced into America.
The nuts are often cooked like potatoes. <bot735> American Chestnut (Bombacopsis glabra A.
Robyns) (roasted seeds) [Neotropics] <bot841> European Chestnut (Castanea sativa)
(roasted fruit) [Europe] <Photos> Other
Crops Where Seeds are Used <bot754> Black Apple (Diospyros digyna
Jacq.) (seeds; wood products) [Cent. America - West Indies] <bot824> Cocoa (Theobroma cacao L.) (fruit
& processed seed) [Central - Northern South America] <bot743> Cocoplum (Fat Pork) (Chrysobalanus
icaco L.) (fruit & roasted seeds) [Mexico-West Indies] <bot759> Durian (Durio zibethinus Murr.) (fruit
& roasted seeds) [SE Asia] <bot741> Moreton Bay Chestnut (Black Bean) (Castanospernum
australe A. Cunningham & Fraser) (wood products; seeds boiled) [NE Australia] <bot124> Opuntia sp. & Palo Verde (Parkinsonia
aculeata ), South Texas <bot705> Winged bean (Psophocarpus
tetragonolobus ) [New Guinea] |