Brown flax seeds

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant. The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.

Seeds have been an important development in the reproduction and spread of flowering plants, relative to more primitive plants such as mosses, ferns and liverworts, which do not have seeds and use other means to propagate themselves. This can be seen by the success of seed plants (both gymnosperms and angiosperms) in dominating biological niches on land, from forests to grasslands both in hot and cold climates.

The term "seed" also has a general meaning that antedates the above — anything that can be sown, e.g. "seed" potatoes, "seeds" of corn or sunflower "seeds". In the case of sunflower and corn "seeds", what is sown is the seed enclosed in a shell or husk, whereas the potato is a tuber.

Seed structure[link]

The parts of an avocado seed (a dicot), showing the seed coat, endosperm, and embryo

A typical seed includes three basic parts: (1) an embryo, (2) a supply of nutrients for the embryo, and (3) a seed coat.

The embryo is an immature plant from which a new plant will grow under proper conditions. The embryo has one cotyledon or seed leaf in monocotyledons, two cotyledons in almost all dicotyledons and two or more in gymnosperms. The radicle is the embryonic root. The plumule is the embryonic shoot. The embryonic stem above the point of attachment of the cotyledon(s) is the epicotyl. The embryonic stem below the point of attachment is the hypocotyl.

Within the seed, there usually is a store of nutrients for the seedling that will grow from the embryo. The form of the stored nutrition varies depending on the kind of plant. In angiosperms, the stored food begins as a tissue called the endosperm, which is derived from the parent plant via double fertilization. The usually triploid endosperm is rich in oil or starch and protein. In gymnosperms, such as conifers, the food storage tissue (also called endosperm) is part of the female gametophyte, a haploid tissue. In some species, the embryo is embedded in the endosperm or female gametophyte, which the seedling will use upon germination. In others, the endosperm is absorbed by the embryo as the latter grows within the developing seed, and the cotyledons of the embryo become filled with this stored food. At maturity, seeds of these species have no endosperm and are termed exalbuminous seeds. Some exalbuminous seeds are bean, pea, oak, walnut, squash, sunflower, and radish. Seeds with an endosperm at maturity are termed albuminous seeds. Most monocots (e.g. grasses and palms) and many dicots (e.g. Brazil nut and castor bean) have albuminous seeds. All gymnosperm seeds are albuminous.

The seed coat (the testa) develops from the tissue, the integument, originally surrounding the ovule. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut) or something more substantial (e.g. thick and hard in honey locust and coconut). The seed coat helps protect the embryo from mechanical injury and from drying out.

In addition to the three basic seed parts, some seeds have an appendage on the seed coat such an aril (as in yew and nutmeg) or an elaiosome (as in Corydalis) or hairs (as in cotton). A scar also may remain on the seed coat, called the hilum, where the seed was attached to the ovary wall by the funiculus.

Kinds of seeds[link]

Many structures commonly referred to as "seeds" are actually dry fruits. Sunflower seeds are sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed. Nuts are the one-seeded, hard shelled fruit, of some plants, with an indehiscent seed, such as an acorn or hazelnut.

Seed production[link]

Seeds are produced in several related groups of plants, and their manner of production distinguishes the angiosperms ("enclosed seeds") from the gymnosperms ("naked seeds"). Angiosperm seeds are produced in a hard or fleshy structure called a fruit that encloses the seeds, hence the name. (Some fruits have layers of both hard and fleshy material). In gymnosperms, no special structure develops to enclose the seeds, which begin their development "naked" on the bracts of cones. However, the seeds do become covered by the cone scales as they develop in some species of conifer.

Seed production in natural plant populations vary widely from year-to-year in response to weather variables, insects and diseases, and internal cycles within the plants themselves. Over a 20-year period, for example, forests composed of loblolly pine and shortleaf pine produced from 0 to nearly 5 million sound pine seeds per hectare.^[1] Over this period, there were six bumper, five poor, and nine good seed crops, when evaluated in regard to producing adequate seedlings for natural forest reproduction.

Seed development[link]

The inside of a Ginkgo seed, showing a well-developed embryo, nutritive tissue (megagametophyte), and a bit of the surrounding seed coat

Diagram of the internal structure of a dicot seed and embryo: (a) seed coat, (b) endosperm, (c) cotyledon, (d) hypocotyl

The seed, which is an embryo with two points of growth (one of which forms the stem, the other the roots) is enclosed in a seed coat with some food reserves. Angiosperm seeds consist of three genetically distinct constituents: (1) the embryo formed from the zygote, (2) the endosperm, which is normally triploid, (3) the seed coat from tissue derived from the maternal tissue of the ovule. In angiosperms, the process of seed development begins with double fertilization and involves the fusion of the egg and sperm nuclei into a zygote. The second part of this process is the fusion of the polar nuclei with a second sperm cell nucleus, thus forming a primary endosperm. Right after fertilization, the zygote is mostly inactive, but the primary endosperm divides rapidly to form the endosperm tissue. This tissue becomes the food the young plant will consume until the roots have developed after germination. The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant, the inner integument forms the tegmen and the outer forms the testa. When the seed coat forms from only one layer, it is also called the testa, though not all such testae are homologous from one species to the next.

In gymnosperms, the two sperm cells transferred from the pollen do not develop seed by double fertilization, but one sperm nucleus unites with the egg nucleus and the other sperm is not used.^[2] Sometimes each sperm fertilizes an egg cell and one zygote is then aborted or absorbed during early development.^[3] The seed is composed of the embryo (the result of fertilization) and tissue from the mother plant, which also form a cone around the seed in coniferous plants such as pine and spruce.

The ovules after fertilization develop into the seeds; the main parts of the ovule are the funicle; which attaches the ovule to the placenta, the nucellus; the main region of the ovule where the megagametophyte develops, the micropyle; a small pore or opening in the ovule where the pollen tube usually enters during the process of fertilization, and the chalaza; the base of the ovule opposite the micropyle, where integument and nucellus are joined together.^[4]

The shape of the ovules as they develop often affects the final shape of the seeds. Plants generally produce ovules of four shapes: the most common shape is called anatropous, with a curved shape. Orthotropous ovules are straight with all the parts of the ovule lined up in a long row producing an uncurved seed. Campylotropous ovules have a curved megagametophyte often giving the seed a tight “C” shape. The last ovule shape is called amphitropous, where the ovule is partly inverted and turned back 90 degrees on its stalk (the funiculus).

In the majority of flowering plants, the zygote's first division is transversely oriented in regards to the long axis, and this establishes the polarity of the embryo. The upper or chalazal pole becomes the main area of growth of the embryo, while the lower or micropylar pole produces the stalk-like suspensor that attaches to the micropyle. The suspensor absorbs and manufacturers nutrients from the endosperm that are used during the embryo's growth.^[5]

The embryo is composed of different parts; the epicotyle will grow into the shoot, the radicle grows into the primary root, the hypocotyl connects the epicotyle and the radicle, the cotyledons form the seed leaves. Monocotyledonous plants have other structures; instead of the hypocotyle-epicotyle, it has a coleoptile that forms the first leaf and connects to the coleorhiza that connects to the primary root and adventitious roots form from the sides. The seeds of corn are constructed with these structures; pericarp, scutellum (single large cotyledon) that absorbs nutrients from the endosperm, endosperm, plumule, radicle, coleoptile and coleorhiza - these last two structures are sheath-like and enclose the plumule and radicle, acting as a protective covering. The testae or seed coats of both monocots and dicots are often marked with patterns and textured markings, or have wings or tufts of hair.

Seed size and seed set[link]

A collection of various vegetable and herb seeds

Seeds are very diverse in size. The dust-like orchid seeds are the smallest, with about one million seeds per gram; they are often embryonic seeds with immature embryos and no significant energy reserves. Orchids and a few other groups of plants are mycoheterotrophs which depend on mycorrhizal fungi for nutrition during germination and the early growth of the seedling. Some terrestrial orchid seedlings, in fact, spend the first few years of their lives deriving energy from the fungi and do not produce green leaves.^[6] At over 20 kg, the largest seed is the coco de mer. Plants that produce smaller seeds can generate many more seeds per flower, while plants with larger seeds invest more resources into those seeds and normally produce fewer seeds. Small seeds are quicker to ripen and can be dispersed sooner, so fall blooming plants often have small seeds. Many annual plants produce great quantities of smaller seeds; this helps to ensure at least a few will end in a favorable place for growth. Herbaceous perennials and woody plants often have larger seeds; they can produce seeds over many years, and larger seeds have more energy reserves for germination and seedling growth and produce larger, more established seedlings after germination.^[7][8]

Seed functions[link]

Seeds serve several functions for the plants that produce them. Key among these functions are nourishment of the embryo, dispersal to a new location, and dormancy during unfavorable conditions. Seeds fundamentally are a means of reproduction and most seeds are the product of sexual reproduction which produces a remixing of genetic material and phenotype variability that natural selection acts on.

Embryo nourishment[link]

Seeds protect and nourish the embryo or young plant. Seeds usually give a seedling a faster start than a sporeling from a spore, because of the larger food reserves in the seed and the multicellularity of the enclosed embryo.

Seed dispersal[link]

Unlike animals, plants are limited in their ability to seek out favorable conditions for life and growth. As a result, plants have evolved many ways to disperse their offspring by dispersing their seeds (see also vegetative reproduction). A seed must somehow "arrive" at a location and be there at a time favorable for germination and growth. When the fruits open and release their seeds in a regular way, it is called dehiscent, which is often distinctive for related groups of plants; these fruits include capsules, follicles, legumes, silicles and siliques. When fruits do not open and release their seeds in a regular fashion they are called indehiscent, which include the fruits achenes, caryopsis, nuts, samaras, and utricles.^[9]

Seed dispersal is seen most obviously in fruits; however many seeds aid in their own dispersal. Some kinds of seeds are dispersed while still inside a fruit or cone, which later opens or disintegrates to release the seeds. Other seeds are expelled or released from the fruit prior to dispersal. For example, milkweeds produce a fruit type, known as a follicle,^[10] that splits open along one side to release the seeds. Iris capsules split into three "valves" to release their seeds.^[11]

By wind (anemochory)[link]

Dandelion seeds are contained within achenes, which can be carried long distances by the wind.

The seed pod of milkweed (Asclepias syriaca)

• Some seeds (e.g., pine) have a wing that aids in wind dispersal.
• The dustlike seeds of orchids are carried efficiently by the wind.
• Some seeds, (e.g. milkweed, poplar) have hairs that aid in wind dispersal.^[12]

Other seeds are enclosed in fruit structures that aid wind dispersal in similar ways:

• Dandelion achenes have hairs.
• Maple samaras have two wings.

By water (hydrochory)[link]

• Some plants, such as Mucuna and Dioclea, produce buoyant seeds termed sea-beans or drift seeds because they float in rivers to the oceans and wash up on beaches.^[13]

By animals (zoochory)[link]

• Seeds (burrs) with barbs or hooks (e.g. acaena, burdock, dock) which attach to animal fur or feathers, and then drop off later.
• Seeds with a fleshy covering (e.g. apple, cherry, juniper) are eaten by animals (birds, mammals, reptiles, fish) which then disperse these seeds in their droppings.
• Seeds (nuts) which are an attractive long-term storable food resource for animals (e.g. acorns, hazelnut, walnut); the seeds are stored some distance from the parent plant, and some escape being eaten if the animal forgets them.

Myrmecochory is the dispersal of seeds by ants. Foraging ants disperse seeds which have appendages called elaiosomes^[14] (e.g. bloodroot, trilliums, Acacias, and many species of Proteaceae). Elaiosomes are soft, fleshy structures that contain nutrients for animals that eat them. The ants carry such seeds back to their nest, where the elaiosomes are eaten. The remainder of the seed, which is hard and inedible to the ants, then germinates either within the nest or at a removal site where the seed has been discarded by the ants.^[15] This dispersal relationship is an example of mutualism, since the plants depend upon the ants to disperse seeds, while the ants depend upon the plants seeds for food. As a result, a drop in numbers of one partner can reduce success of the other. In South Africa, the Argentine ant (Linepithema humile) has invaded and displaced native species of ants. Unlike the native ant species, Argentine ants do not collect the seeds of Mimetes cucullatus or eat the elaiosomes. In areas where these ants have invaded, the numbers of Mimetes seedlings have dropped.^[16]

Seed dormancy[link]

Seed dormancy has two main functions: the first is synchronizing germination with the optimal conditions for survival of the resulting seedling; the second is spreading germination of a batch of seeds over time so that a catastrophe after germination (e.g. late frosts, drought, herbivory) does not result in the death of all offspring of a plant (bet-hedging).^[17] Seed dormancy is defined as a seed failing to germinate under environmental conditions optimal for germination, normally when the environment is at a suitable temperature with proper soil moisture. This true dormancy or innate dormancy is therefore caused by conditions within the seed that prevent germination. Thus dormancy is a state of the seed, not of the environment.^[18] Induced dormancy, enforced dormancy or seed quiescence occurs when a seed fails to germinate because the external environmental conditions are inappropriate for germination, mostly in response to conditions being too dark or light, too cold or hot, or too dry.

Seed dormancy is not the same as seed persistence in the soil or on the plant, though even in scientific publications dormancy and persistence are often confused or used as synonyms.^[19]

Often seed dormancy is divided into four major categories: exogenous; endogenous; combinational; and secondary. A more recent system distinguishes five classes of dormancy:morphological, physiological, morphophysiological, physical and combinational dormancy.^[20]

Exogenous dormancy is caused by conditions outside the embryo including:

• Physical dormancy or hard seed coats occurs when seeds are impermeable to water. At dormancy break a specialized structure, the ‘water gap’, is disrupted in response to environmental cues, especially temperature, so that water can enter the seed and germination can occur. Plant families where physical dormancy occurs include Anacardiaceae, Cannaceae, Convulvulaceae, Fabaceae and Malvaceae.^[21]
• Chemical dormancy considers species that lack physiological dormancy, but where a chemical prevents germination. This chemical can be leached out of the seed by rainwater or snow melt or be deactivated somehow.^[22] Leaching of chemical inhibitors from the seed by rain water is often cited as an important cause of dormancy release in seeds of desert plants, however little evidence exists to support this claim.^[23]

Endogenous dormancy is caused by conditions within the embryo itself, including:

• Morphological dormancy where germination is prevented due to morphological characteristics of the embryo. In some species the embryo is just a mass of cells when seeds are dispersed, it is not differentiated. Before germination can take place both differentiation and growth of the embryo have to occur. In other species the embryo is differentiated but not fully grown (underdeveloped) at dispersal and embryo growth up to a species specific length is required before germination can occur. Examples of plant families where morphological dormancy occurs are Apiaceae, Cycadaceae, Liliaceae, Magnoliaceae and Ranunculaceae.^[24][25]
• Morphophysiological dormancy seeds with underdeveloped embryos, and which in addition have physiological components to dormancy. These seeds therefore require a dormancy-breaking treatments as well as a period of time to develop fully grown embryos. Plant families where morphophysiological dormancy occurs include Apiaceae, Aquifoliaceae, Liliaceae, Magnoliaceae, Papaveraceae and Ranunculaceae.^[24] Some plants with morphophysiological dormancy like Asarum or Trillium species have multiple types of dormancy, one affects radicle (root) growth while the other affects plumule (shoot) growth. The terms "double dormancy" and "2-year seeds" are used for species whose seeds need two years to complete germination or at least two winters and one summer. Dormancy of the radicle (seedling root)is broken during the first winter after dispersal while dormancy of the shoot bud is broken during the second winter.^[24]
• Physiological dormancy means that the embryo can, due to physiological causes, not generate enough power to break through the seed coat, endosperm or other covering structures. Dormancy is typically broken at cool wet, warm wet or warm dry conditions. Abscisic acid is usually the growth inhibitor in seeds and its production can be affected by light.
  • Drying; some plants including a number of grasses and those from seasonally arid regions need a period of drying before they will germinate. The seeds are released but need to have a lower moisture content before germination can begin. If the seeds remain moist after dispersal, germination can be delayed for many months or even years. Many herbaceous plants from temperate climate zones have physiological dormancy that disappears with drying of the seeds. Other species will germinate after dispersal only under very narrow temperature ranges, but as the seeds dry they are able to germinate over a wider temperature range.^[26]

• Combinational dormancy In seeds with combinational dormancy the seed or fruit coat is impermeable to water and the embryo has physiological dormancy. Depending on the species physical dormancy can be broken before or after physiological dormancy is broken.^[25]

• Secondary dormancy* is caused by conditions after the seed has been dispersed and occurs in some seeds when non-dormant seed is exposed to conditions that are not favorable to germination, very often high temperatures. The mechanisms of secondary dormancy are not yet fully understood but might involve the loss of sensitivity in receptors in the plasma membrane.^[27]

The following types of seed dormancy do not involve seed dormancy strictly spoken as lack of germination is prevented by the environment not by characteristics of the seed itself (see Germination):

• Photodormancy or light sensitivity affects germination of some seeds. These photoblastic seeds need a period of darkness or light to germinate. In species with thin seed coats, light may be able to penetrate into the dormant embryo. The presence of light or the absence of light may trigger the germination process, inhibiting germination in some seeds buried too deeply or in others not buried in the soil.
• Thermodormancy is seed sensitivity to heat or cold. Some seeds including cocklebur and amaranth germinate only at high temperatures (30C or 86F) many plants that have seed that germinate in early to mid summer have thermodormancy and germinate only when the soil temperature is warm. Other seeds need cool soils to germinate, while others like celery are inhibited when soil temperatures are too warm. Often thermodormancy requirements disappear as the seed ages or dries.

Not all seeds undergo a period of dormancy. Seeds of some mangroves are viviparous, they begin to germinate while still attached to the parent. The large, heavy root allows the seed to penetrate into the ground when it falls. Many garden plants have seeds that will germinate readily as soon as they have water and are warm enough, though their wild ancestors may have had dormancy, these cultivated plants lack seed dormancy. After many generations of selective pressure by plant breeders and gardeners dormancy has been selected out.

For annuals, seeds are a way for the species to survive dry or cold seasons. Ephemeral plants are usually annuals that can go from seed to seed in as few as six weeks.^[28]

Seed persistence and seed banks[link]

Seed germination[link]

Germinating sunflower seedlings.

Seed germination is a process by which a seed embryo develops into a seedling. It involves the reactivation of the metabolic pathways that lead to growth and the emergence of the radicle or seed root and plumule or shoot. The emergence of the seedling above the soil surface is the next phase of the plant's growth and is called seedling establishment.^[29]

Three fundamental conditions must exist before germination can occur. (1) The embryo must be alive, called seed viability. (2) Any dormancy requirements that prevent germination must be overcome. (3) The proper environmental conditions must exist for germination.

Seed viability is the ability of the embryo to germinate and is affected by a number of different conditions. Some plants do not produce seeds that have functional complete embryos or the seed may have no embryo at all, often called empty seeds. Predators and pathogens can damage or kill the seed while it is still in the fruit or after it is dispersed. Environmental conditions like flooding or heat can kill the seed before or during germination. The age of the seed affects its health and germination ability: since the seed has a living embryo, over time cells die and cannot be replaced. Some seeds can live for a long time before germination, while others can only survive for a short period after dispersal before they die.

Seed vigor is a measure of the quality of seed, and involves the viability of the seed, the germination percentage, germination rate and the strength of the seedlings produced.^[30]

The germination percentage is simply the proportion of seeds that germinate from all seeds subject to the right conditions for growth. The germination rate is the length of time it takes for the seeds to germinate. Germination percentages and rates are affected by seed viability, dormancy and environmental effects that impact on the seed and seedling. In agriculture and horticulture quality seeds have high viability, measured by germination percentage plus the rate of germination. This is given as a percent of germination over a certain amount of time, 90% germination in 20 days, for example. 'Dormancy' is covered above; many plants produce seeds with varying degrees of dormancy, and different seeds from the same fruit can have different degrees of dormancy.^[31] It's possible to have seeds with no dormancy if they are dispersed right away and do not dry (if the seeds dry they go into physiological dormancy). There is great variation amongst plants and a dormant seed is still a viable seed even though the germination rate might be very low.

Environmental conditions effecting seed germination include; water, oxygen, temperature and light.

Three distinct phases of seed germination occur: water imbibition; lag phase; and radicle emergence.

In order for the seed coat to split, the embryo must imbibe (soak up water), which causes it to swell, splitting the seed coat. However, the nature of the seed coat determines how rapidly water can penetrate and subsequently initiate germination. The rate of imbibition is dependent on the permeability of the seed coat, amount of water in the environment and the area of contact the seed has to the source of water. For some seeds, imbibing too much water too quickly can kill the seed. For some seeds, once water is imbibed the germination process cannot be stopped, and drying then becomes fatal. Other seeds can imbibe and lose water a few times without causing ill effects, but drying can cause secondary dormancy.

Inducing germination[link]

A number of different strategies are used by gardeners and horticulturists to break seed dormancy.

Scarification which allows water and gases to penetrate into the seed, include methods that physically break the hard seed coats or soften them by chemicals. Means of scarification include soaking in hot water or poking holes in the seed with a pin or rubbing them on sandpaper or cracking with a press or hammer. Soaking the seeds in solvents or acids is also effective for many seeds. Sometimes fruits are harvested while the seeds are still immature and the seed coat is not fully developed and sown right away before the seed coat become impermeable. Under natural conditions seed coats are worn down by rodents chewing on the seed, the seeds rubbing against rocks (seeds are moved by the wind or water currents), by undergoing freezing and thawing of surface water, or passing through an animal's digestive tract. In the latter case, the seed coat protects the seed from digestion, while often weakening the seed coat such that the embryo is ready to sprout when it gets deposited (along with a bit of fertilizer) far from the parent plant. Microorganisms are often effective in breaking down hard seed coats and are sometimes used by people as a treatment, the seeds are stored in a moist warm sandy medium for several months under non-sterile conditions.

Stratification also called moist-chilling is a method to break down physiological dormancy and involves the addition of moisture to the seeds so they imbibe water and then the seeds are subject to a period of moist chilling to after-ripen the embryo. Sowing outside in late summer and fall and allowing to overwinter outside under cool conditions is an effective way to stratify seeds, some seeds respond more favorably to periods of oscillating temperatures which are part of the natural environment.

Leaching or the soaking in water removes chemical inhibitors in some seeds that prevent germination. Rain and melting snow naturally accomplish this task. For seeds planted in gardens, running water is best - if soaked in a container, 12 to 24 hours of soaking is sufficient. Soaking longer, especially in stagnant water that is not changed, can result in oxygen starvation and seed death. Seeds with hard seed coats can be soaked in hot water to break open the impermeable cell layers that prevent water intake.

Other methods used to assist in the germination of seeds that have dormancy include prechilling, predrying, daily alternation of temperature, light exposure, potassium nitrate, the use of plant growth regulators like gibberellins, cytokinins, ethylene, thiourea, sodium hypochlorite plus others.^[32] Some seeds germinate best after a fire, for some seeds fire cracks hard seed coats while in other seeds chemical dormancy is broken in reaction to the presence of smoke, liquid smoke is often used by gardeners to assist in the germination of these species.^[33]

Origin and evolution[link]

The origin of seed plants is a problem that still remains unsolved. However, more and more data tends to place this origin in the middle Devonian. The description in 2004 of the proto-seed Runcaria heinzelinii in the Givetian of Belgium is an indication of that ancient origin of seed-plants. As with modern ferns, most land plants before this time reproduced by sending spores into the air, that would land and become whole new plants.

The first "true" seeds are described from the upper Devonian, which is probably the theater of their true first evolutionary radiation. The seed plants progressively became one of the major elements of nearly all ecosystems.

Economic importance[link]

A variety of bean seeds.

Edible seeds[link]

Many seeds are edible and the majority of human calories comes from seeds,^[34] especially from cereals, legumes and nuts. Seeds also provide most cooking oils, many beverages and spices and some important food additives. In different seeds the seed embryo or the endosperm dominates and provides most of the nutrients. The storage proteins of the embryo and endosperm differ in their amino acid content and physical properties. For example the gluten of wheat, important in providing the elastic property to bread dough is strictly an endosperm protein.

Seeds are used to propagate many crops such as cereals, legumes, forest trees, turfgrasses and pasture grasses. Particularly in developing countries, a major constraint faced is the inadequacy of the marketing channels to get the seed to poor farmers.^[35] Thus the use of farmer-retained seed remains quite common.

Seeds are also eaten by animals, and are fed to livestock. Many seeds are used as birdseed.

Poison and food safety[link]

While some seeds are edible, others are harmful, poisonous or deadly.^[36] Plants and seeds often contain chemical compounds to discourage herbivores and seed predators. In some cases, these compounds simply taste bad (such as in mustard), but other compounds are toxic or break down into toxic compounds within the digestive system. Children, being smaller than adults, are more susceptible to poisoning by plants and seeds.^[37]

A deadly poison, ricin, comes from seeds of the castor bean. Reported lethal doses are anywhere from two to eight seeds,^[38][39] though only a few deaths have been reported when castor beans have been ingested by animals.^[40]

In addition, seeds containing amygdalin—apple, apricot, bitter almond,^[41] peach, plum, cherry, quince, and others—when consumed in sufficient amounts, may cause Cyanide poisoning.^[41][42] Other seeds that contain poisons include annona, cotton, custard apple, datura, uncooked durian, golden chain, horse-chestnut, larkspur, locoweed, lychee, nectarine, rambutan, rosary pea, sour sop, sugar apple, wisteria, and yew.^[43][44] The seeds of the strychnine tree are also poisonous, containing the poison strychnine.

The seeds of many legumes, including the common bean (Phaseolus vulgaris), contain proteins called lectins which can cause gastric distress if the beans are eaten without cooking. The common bean and many others, including the soybean, also contain trypsin inhibitors which interfere with the action of the digestive enzyme trypsin. Normal cooking processes degrade lectins and trypsin inhibitors to harmless forms.^[45]

Please see the category plant toxins for further relevant articles.

Other uses[link]

Flax seed oil (in bottles) and coconut oil (in jars in the middle).

Cotton fiber grows attached to cotton plant seeds. Other seed fibers are from kapok and milkweed.

Many important nonfood oils are extracted from seeds. Linseed oil is used in paints. Oil from jojoba and crambe are similar to whale oil.

Seeds are the source of some medicines including castor oil, tea tree oil and the discredited cancer drug, Laetrile.

Many seeds have been used as beads in necklaces and rosaries including Job's tears, Chinaberry, rosary pea, and castor bean. However, the latter three are also poisonous.

Other seed uses include:

• Seeds once used as weights for balances.
• Seeds used as toys by children, such as for the game Conkers.
• Resin from Clusia rosea seeds used to caulk boats.
• Nematicide from milkweed seeds.
• Cottonseed meal used as animal feed and fertilizer.

Seed records[link]

The massive fruit of the coco de mer.

• The oldest viable carbon-14-dated seed that has grown into a plant was a Judean date palm seed about 2,000 years old, recovered from excavations at Herod the Great's palace on Masada in Israel. It was germinated in 2005.^[46] (A reported regeneration of Silene stenophylla (narrow-leafed campion) from material preserved for 31,800 years in the Siberian permafrost was achieved using fruit tissue, not seed.^[47][48])

• The largest seed is produced by the coco de mer, or "double coconut palm", Lodoicea maldivica. The entire fruit may weigh up to 23 kilograms (50 pounds) and usually contains a single seed.^[49]

• The earliest fossil seeds are around 365 million years old from the Late Devonian of West Virginia. The seeds are preserved immature ovules of the plant Elkinsia polymorpha.^[50]

See also[link]

Biology portal

• Biological dispersal
• Germination
• List of edible seeds
• List of world's largest seeds
• Recalcitrant seed
• Seed company
• Seed enhancement
• Seed orchard
• Seed paper
• Seed predation
• Seed saving
• Seed testing
• Seed trap
• Seedbed
• Seedling
• Soil seed bank
• Stratification

References[link]

External links[link]

Wikimedia Commons has media related to: Seed

Look up seed in Wiktionary, the free dictionary.

• List of Common Botanical Seed Names
• The Seed Site: collecting, storing, sowing, germinating, and exchanging seeds, with pictures of seeds, seedpods and seedlings.
• The Seed Biology Place seed structure, dormany, evolution, ecology, etc.
• Flavon's Secret Flower Garden - Pictures of Japanese plant seeds, fruits and etc.
• The Millennium Seed Bank Project Kew Garden's ambitious preservation project
• The Svalbard Global Seed Vault - a backup facility for the world's seed banks

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Cody Chesnutt
Cody ChesnuTT at the 2011 Ilosaarirock festival.
Background information
Born	1968 (age 43–44)
Origin	Atlanta, Georgia
Genres	Rock and roll, R&B, soul
Occupations	Composer, musician
Associated acts	The Crosswalk

Cody Chesnutt performing at Martin Luther's Rebel Soul Fest in San Francisco, July 2008.

Cody Chesnutt (stylized as Cody ChesnuTT, born 1968^[1]) is an American R&B and neo soul musician from Atlanta, Georgia.

Biography[link]

Chesnutt's music blends elements of rock, funk, soul, hip hop, and blues. After relocating to Los Angelos, Chesnutt found work with Death Row records, writing and producing five songs for the male R&B group Six Feet Deep. Chesnutt and his former band, The Crosswalk, had a brief stint with Hollywood Records in which they were later booted from the label. The band subsequently broke up and Chesnutt released a double LP in 2002 entitled The Headphone Masterpiece, which was recorded on a 4-track cassette recorder in his bedroom recording studio, which he calls "The Sonic Promiseland".

His closest brush with mainstream success came in 2002, when the hip hop group The Roots remade a song from his album, "The Seed", for their album Phrenology, as "The Seed (2.0)". Chesnutt plays guitar and sings vocals on the track, and appears in its music video, which received heavy airplay on MTV and BET. At the height of his popularity, Chesnutt's backing band consisted of drummer Craig Waters, now with the band The Bellrays, and bassist Aaron Ebensperger. In October 2003, Cody Chesnutt was nominated for the prestigious Shortlist Music Prize, and performed in the ceremony for the prize at the Wiltern Theatre in California.

In 2006, Chesnutt appeared in the music documentary Dave Chappelle's Block Party, which was originally recorded in September 2004. The same year, he recorded the track "Boils" for the 4AD records album Plague Songs. On his Myspace announced an upcoming album titled The Live Release, which he has been performing around the world but is yet to be released. In 2007, he performed at the Pop Montreal music festival as one of the headliners.

In 2010 he released an EP called Black Skin No Value. Furthermore he stated in an interview that he will publish his second big album Landing On A Hundred in 2012.^[2]

Discography[link]

Albums[link]

• 2002: The Headphone Masterpiece
• 2006: The Live Release (unpublished)
• 2010: Black Skin No Value (EP)
• 2012: Landing On A Hundred^[3]

Singles[link]

• 2001: Look Good in Leather ("AXE Instinct"-Werbespot (2009))
• 2002: "The World Is Coming"^[4]
• 2002: "The Seed (2.0)" (featuring The Roots) (UK #33)
• 2006: "The Last Adam"
• 2008: "Afrobama"^[5]
• 2010: "Come Back Like Spring" ^[6]

Notes[link]

External links[link]

• Cody Chesnutt on Myspace

Eric Carle (born June 25, 1929) is a children's book author and illustrator who is most famous for his book The Very Hungry Caterpillar, which has been translated into over 500 languages. Since The Very Hungry Caterpillar was published in 1969, Eric Carle has illustrated more than 70 books, many best sellers, most of which he also wrote, and more than 103 million copies of his books have been sold around the world.

Early life[link]

Born in Syracuse, New York, in 1929 to German immigrants Johanna and Erich Carle, Eric moved back to Germany with his parents in the mid 1930s when he was six years old; his mother, homesick for Germany, took the family back to Stuttgart. He was educated there, and graduated from the Akademie der Bildenden Künste Stuttgart. Eric's father was drafted into the German army in 1939 at the beginning of the World War II and was taken prisoner of war by the Soviet Forces when Germany capitulated in in the Sping of 1945. He returned home in late 1947, weighing 85 pounds. "When he came back, he was a broken man." He was, in Eric Carle's own words in a Guardian interview a "sick man, psychologically, physically devastated." Eric had been sent to the small town of Schwenningen to escape the bombings of Stuttgart.^[1] When Eric was 15, the German government conscripted him and other boys of his age to dig trenches on the Siegfried line. He doesn't care to think about it too deeply, although his wife, he says, thinks he still suffers from post-traumatic stress. "You know about the Siegfried line? To dig trenches. And the first day three people were killed a few feet away. None of us children -- Russian prisoners and other conscripted workers. The nurses came and started crying. And in Stuttgart, our home town, our house was the only one standing. When I say standing, I mean the roof and windows are gone, and the doors. And, well, there you are." Always homesick for America, Eric dreamed of returning one day to the United States, so he moved to New York City in 1952 with only $40 to his name. Once there, he landed a job as a graphic designer in the promotion department of The New York Times. He was drafted into the U.S. Army during the Korean War and stationed in Germany^[2] with the Second Armored Division and appointed the position of mail clerk.^[1] After returning from the service, Carle returned to his old job with The New York Times and later became the art director of an advertising agency.

Writing and illustrating career[link]

Educator and author Bill Martin Jr., after noticing an illustration of a red lobster Carle had created for an advertisement, asked him to illustrate a story. Brown Bear, Brown Bear, What Do You See? was the result of their collaboration, and became a best-seller. This began Carle’s true career; soon he was writing and illustrating his own stories. His first wholly original book was 1,2,3 to the Zoo, followed quickly by The Very Hungry Caterpillar.

Style[link]

Eric Carle’s art is distinctive and instantly recognizable. His art work is created in collage technique, using hand-painted papers, which he cuts and layers to form bright and colorful images. Many of his books have an added dimension—die-cut pages, twinkling lights as in The Very Lonely Firefly, even the lifelike sound of a cricket’s song as in The Very Quiet Cricket.

The themes of his stories are usually drawn from his extensive knowledge and love of nature— an interest shared by most small children. Carle attempts to make his books not only entertaining, but also to offer his readers the opportunity to learn something about the world around them. When writing, Carle attempts to recognize children's feelings, inquisitiveness and creativity, as well as stimulate their intellectual growth; it is for these reasons (in addition to his unique artwork) that many feel his books have been such a success.

Quotes[link]

“With many of my books I attempt to bridge the gap between the home and school. To me home represents, or should represent; warmth, security, toys, holding hands, being held. School is a strange and new place for a child. Will it be a happy place? There are new people, a teacher, classmates—will they be friendly?

I believe the passage from home to school is the second biggest trauma of childhood; the first is, of course, being born. Indeed, in both cases we leave a place of warmth and protection for one that is unknown. The unknown often brings fear with it. In my books I try to counteract this fear, to replace it with a positive message. I believe that children are naturally creative and eager to learn. I want to show them that learning is really both fascinating and fun.” -Eric Carle^[3]

Later life[link]

Eric Carle has a son and a daughter. He currently divides his time between the Florida Keys and the Hills of North Carolina. For over 30 years, Carle and his second wife, Bobbie Morrison, lived in Northampton, Massachusetts.^[2]

With his wife, Eric Carle founded The Eric Carle Museum of Picture Book Art, a 44,000 sq ft (4,100 m²) museum devoted to the art of children's books in Amherst located adjacent to Hampshire College as part of the Hampshire College Cultural Village. The Museum has welcomed more than 500,000 visitors since it opened its doors in 2002. Carle received an honorary doctorate from Bates College in 2007.^[4]

Google paid tribute to Carle and his book The Very Hungry Caterpillar by asking him to design their logo "Google doodle", on their home page on March 20, 2009, celebrating the first day of spring. (Carle also designed "Google doodle" for autumn theme for the use in Southern Hemisphere.)

His book The Very Hungry Caterpillar was chosen as the book for Jumpstart's 2009 Read For the Record program on October 8. Read For the Record encourages educators, librarians and parents to try to have as many as possible read the same book and the same day all over the world.

Works[link]

1967, Brown Bear, Brown Bear, What Do You See? (illustrator)
1968, 1, 2, 3 to the Zoo
1969, The Very Hungry Caterpillar
1970, Pancakes, Pancakes!
1970, The Tiny Seed
1970, Tales of the Nincompoop (illustrator)
1970, The Boastful Fisherman (illustrator)
1971, Feathered Ones and Furry (illustrator)
1971, The Scarecrow Clock (illustrator)
1971, Do You Want to Be My Friend?
1972, Rooster’s Off to See the World
1972, The Very Long Tail
1972, The Secret Birthday Message
1972, Walter the Baker
1973, Do Bears Have Mothers Too? (illustrator)
1973, Have You Seen My Cat?
1973, I See a Song, 1973

1974, Split-page book collection:

My Very First Book of Numbers

My Very First Book of Colors

My Very First Book of Shapes

My Very First Book of Words

1974, Why Noah Chose the Dove (illustrator)
1974, All About Arthur
1975, The Hole in the Dike (illustrator)
1975, The Mixed-Up Chameleon
1976, Eric Carle’s Storybook, Seven Tales by the Brothers Grimm
1977, The Grouchy Ladybug
1978, Watch Out! A Giant!
1978, Seven Stories by Hans Christian Andersen (sequel to Seven Tales by the Brothers Grimm)
1980, Twelve Tales from Aesop
1981, The Honeybee and the Robber
1982, Otter Nonsense (illustrator)
1982, Catch the Ball!
1982, What's for Lunch
1983, Chip Has Many Brothers (illustrator)
1984, The Very Busy Spider
1985, The Foolish Tortoise (illustrator)
1985, The Greedy Python (illustrator, companion to The Foolish Tortoise)
1985, The Mountain that Loved a Bird (illustrator)
1986, All Around Us
1986, Papa, Please Get the Moon for Me

1986, Group of small-format books:

My Very First Book of Sounds

My Very First Book of Food

My Very First Book of Tools

My Very First Book of Touch

My Very First Book of Motion

My Very First Book of Growth

My Very First Book of Homes

My Very First Book of Heads

1986, All in a Day (Mitsumasa Anno editor)
1987, A House for Hermit Crab
1988, The Lamb and the Butterfly (illustrator)

1988, Eric Carle’s Treasury of Classic Stories for Children
1989, Animals Animals (illustrator)
1990, The Very Quiet Cricket
1991, Polar Bear, Polar Bear, What Do You Hear? (illustrator)
1991, Dragons Dragons (illustrator)
1992, Draw Me a Star
1993, Today Is Monday
1994, My Apron
1995, The Very Lonely Firefly
1996, Little Cloud
1997, From Head to Toe
1997, Flora and Tiger: 19 very short stories from my life
1998, Hello, Red Fox
1998, You Can Make a Collage: A Very Simple How-to Book
1999, The Very Clumsy Click Beetle
2000, Does A Kangaroo Have A Mother, Too?
2000, Dream Snow
2002, “Slowly, Slowly, Slowly,” said the Sloth
2003, Where Are You Going? To See My Friend! (with Kazuo Iwamura)
2003, Panda Bear, Panda Bear, What Do You See? (illustrator)
2004, Mister Seahorse
2005, 10 Little Rubber Ducks
2006, My Very First Book of Numbers
2007, Baby Bear, Baby Bear, What Do You See?
2008, The Rabbit and the Turtle
2009, Google Logo Design (illustrator)
2009, The Very Hungry Caterpillar, Pop-Up Edition (40th Anniversary Tribute Book)
2011, The Artist Who Painted A Blue Horse

References[link]

1. ^ ^{a b} Carle, Eric (1996). The Art of Eric Carle. New York, NY: Philomel Books. ISBN 0-399-24600-2. 
2. ^ ^{a b} Bernstein, Fred A. (2007-12-13). "Hungry Caterpillar in the Florida Keys". The New York Times. http://www.nytimes.com/2007/12/13/garden/13carle.html?_r=1&oref=slogin. 
3. ^ http://www.eric-carle.com/bio.html
4. ^ NISSY"Eric Carle". Bates College. http://www.bates.edu/x157809.xml. Retrieved 2009-02-02. 

External links[link]

• Eric Carle's web site
• The Eric Carle Museum of Picture book Art web site
• Speech by Eric Carle at Bates College Commencement 2007
• This one's got legs - interview of Eric Carle by Emma Brockes in The Guardian newspaper 14 March 2009
• Daily Telegraph website reports Google logo design

Books portal

Laurie Berkner (born March, 1969, in Neuilly-sur-Seine, France of American parents) is an American musician best known for her work as a children's musical artist. Berkner plays guitar and sings in the Laurie Berkner Band, along with pianist Susie Lampert, bassist Adam Bernstein, and drummer Bobby Golden. She is a popular artist in the Kindie rock genre.^[1]

Biography[link]

Growing up in Princeton, New Jersey, Berkner was involved in choirs, bands and musical theater. As a student at Rutgers University, she toured Europe as a choir soloist and an orchestral guitar player. After working as a summer-camp music counselor, she spent several years as a children's music specialist for day care centers and preschools in the New York area.

In 1992, she began to perform as a professional rock musician, playing in an all-female cover band called Lois Lane. When she started a band that played original music, Red Onion (Berkner, Brian Mueller, Adam Bernstein and Alan Lerner), she found song-writing to be a struggle—a problem that disappeared when she started writing children's music. "Writing music for kids has not been a struggle at all," Berkner has said. "The more I started working on material for children, the more I realized that it opened up creativity in me that I never knew I had."^[2]

Some of her first performances as a children's musician were birthday party gigs at $125 a show. "Those days were intense,” she told The New York Times. “I used to arrive early and memorize every child’s name, so I could feel like I knew them.”^[3]

In 1997, working with Susie Lampert, Mueller and guest bassist Adam Bernstein, she put out her first album, Whaddaya Think of That? as a cassette-only release. She had been encouraged to record by the parents of the children she worked with. "The children were really responding to the music we created together," she said.^[4] The album contained original songs like "We Are the Dinosaurs" and "I Know a Chicken", along with covers of classics like "The Cat Came Back" and "Wimoweh (The Lion Sleeps Tonight)".

In 1998, Berkner formed her own independent record company, Two Tomatoes Records, to release her second album, Buzz Buzz, which includes such Berkner standards as "Pig on Her Head" and "Monster Boogie". With 1999's Victor Vito, Berkner achieved national fame, appearing on the FX network's American Baby Show and winning a Parent's Guide to Children's Media Award. Her latest album is Rocketship Run, which came out in August 2008.

Berkner's audience increased dramatically when she appeared on The Today Show in 2001. Since then, she has played in high-profile locations such as Carnegie Hall and Lincoln Center; she has also played at the White House Easter Egg Roll.^[5] Berkner also played a free concert in Central Park to celebrate Earth Day, which was attended by fifteen thousand people.^[6]

Mueller, who is married to Berkner, left the band in 2006 "to keep the couple’s personal and professional lives separate", and was replaced by Adam Bernstein.^[3] In 2008, Bobby Golden became the band's drummer after producing Rocketship Run," as well as "We Are The Laurie Berkner Band" and all of her songs for Jack's Big Music Show.

Her music is generally in a major key and in what Berkner calls the "human tempo": 100-120 beats per minute, the speed of walking or marching. Her lyrics have been called "self-effacing and occasionally confessional".

Berkner was also a judge for the 10th annual Independent Music Awards to support independent artists' careers.^[7]

Other media[link]

Berkner regularly appears on Nick Jr. (with Lampert and Bernstein), a television network aimed at children, in music videos played between programs and on the program Jack's Big Music Show. Berkner has also appeared in Jamarama Live!, a touring music festival for children sponsored by Noggin, and in the 2006 Macy's Thanksgiving Day Parade. In 2009, she was featured on Ziggy Marley's children's album Family Time in a song called "Future Man, Future Lady".

Berkner has written two children's books: Victor Vito and Freddie Vasco, based on her song "Victor Vito", and Story of My Feelings. She has also put out a video and DVD, We Are...The Laurie Berkner Band; the DVD, has sold more than 400,000 copies since its 2006 release.^[3]

Works[link]

[edit] Albums^[8]

• Whaddaya Think of That? (1997)

1. We Are the Dinosaurs
2. Doodlebugs
3. Down Down Baby
4. She'll Be Comin' Round the Mountain
5. Bring Your Clothes
6. I'm a Little Snowflake
7. The Animal Fair
8. What Falls in the Fall
9. These Are My Glasses
10. ABCD Medley
11. I Know a Chicken
12. Wimoweh (The Lion Sleeps Tonight)
13. I Love My Rooster
14. The Cat Came Back
15. Can You Imagine
16. (I'm Gonna Eat) On Thanksgiving Day
17. All the Pretty Little Horses
18. The Airplane Song
19. 123
20. Last Night I Had a Dream
21. The Great Big Dog

• Buzz, Buzz (1998)

1. I Really Love to Dance
2. The Pretzel Store
3. Pig On Her Head
4. I've Been Working on the Railroad
5. Bumblebee (Buzz Buzz)
6. Telephone
7. There's a Little Wheel A-Turnin' In My Heart
8. Monster Boogie
9. In the Clouds
10. The Cookie Bakers of the Night
11. The More We Get Together
12. I'm a Mess
13. Ice Cream Cone
14. Clean It Up
15. Little Red Caboose
16. Rum Sun Sum
17. Magic Box
18. The Valley of Vegetables
19. Popcorn Calling Me
20. Lots of Little Pigs
21. The Erie Canal
22. I Had a Friend