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

Nick Cave
Nick Cave at an event in New York City, 2009
Background information
Born	(1957-09-22) 22 September 1957 (age 54) Warracknabeal, Victoria, Australia
Genres	Post-punk, gothic rock,[1][2] alternative rock, garage rock
Occupations	Singer-songwriter, multi-instrumentalist, writer, actor, composer
Instruments	Guitar, piano, keyboards, vocals
Years active	1973–present
Labels	Mute
Associated acts	Boys Next Door, Nick Cave and the Bad Seeds, Grinderman, The Birthday Party

Nicholas Edward "Nick" Cave (born 22 September 1957) is an Australian musician, songwriter, author, screenwriter, composer and occasional film actor.

He is best known for his work as a frontman of the critically acclaimed rock band Nick Cave and the Bad Seeds, established in 1983, a group known for its eclectic influences and musical styles. Before that, he had fronted the group The Birthday Party in the early 1980s, a band renowned for its highly gothic,^[1][2] challenging lyrics and violent sound influenced by free jazz, blues, and post-punk. In 2006, he formed the garage rock band Grinderman that released its debut the following year. Cave's music is generally characterised by emotional intensity, a wide variety of influences and lyrical obsessions with religion, death, love and violence.^[3]

Upon Cave's induction into the ARIA Hall of Fame, ARIA Awards committee chairman Ed St John said, “Nick Cave has enjoyed—and continues to enjoy—one of the most extraordinary careers in the annals of popular music. He is an Australian artist like Sidney Nolan is an Australian artist—beyond comparison, beyond genre, beyond dispute."^[4]

Youth, education and family[link]

Cave was born in the small town of Warracknabeal in the state of Victoria, Australia, to Dawn Cave (née Treadwell) and Colin Frank Cave. He has two brothers: Tim (b. 1952) and Peter (b. 1954), and a sister, Julie (b. 1959). As a child, he lived in Warracknabeal and then Wangaratta in rural Victoria. His father was an English teacher and administrator, with a love of literature, and his mother was a librarian. Cave's paternal grandfather's surname was originally Landvoigt, he later in his life became known as Frank Jason Cave.^[5][6][7][8]

Raised as an Anglican, Cave sang in the boys choir at Wangaratta Cathedral. He grew to detest the attitudes of small-town Australia, and he was often in trouble with the local school authorities,^[9] so his parents sent him to boarding school at Melbourne's Caulfield Grammar School in 1970. Cave joined the school choir under choirmaster Norman Kaye, and also benefited from having a piano in his home. The following year he became a "day boy" when his family moved to Murrumbeena, a suburb of Melbourne. Cave was 19 when his father was killed in a car accident; at the moment he was informed of this, his mother Dawn Cave was bailing him out of a St Kilda police station for a charge of burglary. Cave would later recall that his father "died at a point in my life when I was most confused", and "the loss of my father created in my life a vacuum, a space in which my words began to float and collect and find their purpose".^[10]

After his secondary schooling, Cave studied painting (Fine Art) at the Caulfield Institute of Technology (now Monash University, Caulfield campus) in 1976, but dropped out in 1977 to pursue music. He also began using heroin around this time.^{[citation needed]} On 28 March 2008, he received an honorary Doctor of Laws from this university.

Music career[link]

Early years and The Birthday Party (1973–83)[link]

In 1973, Cave met Mick Harvey (guitar), Phill Calvert (drums), John Cochivera (guitar), Brett Purcell (bass), and Chris Coyne (saxophone); fellow students at Caulfield Grammar. They founded a band with Cave as singer. Their repertoire consisted of proto-punk cover versions of songs by Lou Reed, David Bowie, Alice Cooper, Roxy Music and Alex Harvey, among others. Later, the line-up slimmed down to four members including Cave's friend Tracy Pew on bass. In 1977, after leaving school, they adopted the name The Boys Next Door and began playing predominantly original material. Guitarist and songwriter Rowland S. Howard joined the band in 1978, expanding to five members.

From 1977 until their dissolution in 1983 (by which time they were known as The Birthday Party) the band explored various styles. They were a part of Melbourne's post-punk music scene in the late 1970s, playing hundreds of live shows in Australia before changing their name to the Birthday Party in 1980 and moving to London, then West Berlin. Cave's Australian girlfriend and muse Anita Lane accompanied them to London. The band were notorious for their provocative live performances which featured Cave shrieking, bellowing and throwing himself about the stage, backed up by harsh pounding rock music laced with guitar feedback. Cave utilised old testament imagery with lyrics about sin, curses and damnation.^[1] The lyrics were full of "American gothic imagery", talking about horror stories.^[1] The single "Release the Bats" with its story about "vampire sex" was "influential" in the emerging "gothic scene".^[1][2] At that time, Cave also became a regular member of a gothic club in London called The Batcave.^[11]

After establishing a cult following in Europe and Australia, The Birthday Party disbanded in 1984. Howard and Cave found it difficult to continue working together and both were rather worn down from alcohol and drug use.

Cave and the Seeds (1984-present)[link]

Cave performing in 1986

The band with Cave as their leader and frontman has released fourteen studio albums. Their most recent album, Dig, Lazarus, Dig!!! was released on 8 April 2008. Though their sound tends to change considerably from one album to another, the one constant of the band is an unpolished blending of disparate genres, and song structures which provide a vehicle for Cave's virtuosic, frequently histrionic theatrics. NME used the sentence "gothic psycho-sexual apocalypse" to describe the "menace" present in the lyrics of the title track.^[12]

Critics Stephen Thomas Erlewine and Steve Huey write, "With the Bad Seeds, Cave continued to explore his obsessions with religion, death, love, America, and violence with a bizarre, sometimes self-consciously eclectic hybrid of blues, gospel, rock, and arty post-punk, although in a more subdued fashion than his work with the Birthday Party".^[3] Pitchfork Media calls the group one of rock's "most enduring, redoubtable" bands, with an accomplished discography.^[13] A documentary film about the band The Road to God Knows Where/Life at paradiso directed by Uli M Schueppel, about their 1989 tour, was voted in the year 2008, under the 20 best musicmovies of all the time of the reader and journalists of Total Film.

Cave and the band curated an edition of the famous All Tomorrow's Parties music festival, the first in Australia, throughout the country in January 2009.

Solo work and Grinderman[link]

In addition to his performances with Nick Cave and the Bad Seeds, Cave has, since the 1990s, performed live 'solo' tours with himself on piano/vocals, Warren Ellis on violin/accordion and various others on bass and drums. The current trio are Bad Seeds' Martyn P. Casey, Jim Sclavunos and Ellis (nicknamed the Mini-Seeds). In 2006, this line-up, now including Cave on electric guitar, continued his 'solo' tours performing Bad Seeds material.

In the same year three other Bad Seeds, Mick Harvey, Thomas Wydler and James Johnston, undertook Harvey's first 'solo' tours of Europe and Australia performing material from his own albums. Melbourne double bassist Rosie Westbrook completed the quartet.

An album of new material by Cave's 'solo' quartet, now named Grinderman, was released in March 2007.

Nick Cave 'solo' and Grinderman both played at the All Tomorrow's Parties music festival in April 2007. This was Grinderman's first public performance. Bobby Gillespie from Primal Scream accompanied Grinderman on backing vocals and percussion.

In December 2011, after performing at Meredith Music Festival, Cave announced that Grinderman were over.^{[14][dead link]}

Soundtrack involvement[link]

Many of Nick Cave's songs have found their way into movie soundtracks. One of the earliest to feature Cave's distinctive style by incorporating him as part of the movie's music scene—circa 1979—was Dogs in Space, a film by Richard Lowenstein.^[15] Cave performed parts of the Boys Next Door song "Shivers" twice during the film, once on video and once live.

Another early fan of Cave's was German director Wim Wenders, who lists Cave, along with Lou Reed and Portishead, as among his favorites.^[16] Two of Cave's songs were featured in his 1987 film Wings of Desire.^[17] Nick Cave and the Bad Seeds also make a cameo appearance in this film. Two more songs were included in Wenders' 1993 sequel Faraway, So Close!, including the title track. The soundtrack for Wenders' 1991 film Until the End of the World features Cave's "(I'll Love You) Till the End of the World." His most recent production, Palermo Shooting, also contains a Nick Cave song, as does his 2003 documentary The Soul of a Man.^[18]

Cave's songs have also appeared in a number of Hollywood blockbusters and major TV shows. For instance, his "There is a Light" appears on the 1995 soundtrack for Batman Forever, and "Red Right Hand" appeared in a number of films and TV shows, including The X-Files, Dumb & Dumber; Scream, its sequels Scream 2 and 3, and Hellboy (performed by Pete Yorn). In Scream 3, the song was given a reworking with Cave writing new lyrics and adding an orchestra to the arrangement of the track. This version appears on The Bad Seeds B-Sides and Rarities album. The song "People Ain't No Good" was featured in the animated movie Shrek 2, as well as in one of the episodes of the television series The L Word. Cave also sang a cover of The Beatles' "Let It Be," for the 2001 film I Am Sam.

Original material written for movie productions includes the song "To Be By Your Side," for the soundtrack of the 2001 French documentary Le Peuple Migrateur (called Winged Migration in the US). Cave composed the soundtrack for the 2005 film The Proposition with fellow Australian and Bad Seed Warren Ellis. Cave and Ellis once again collaborated on the music for the 2007 film The Assassination of Jesse James by the Coward Robert Ford. Also in 2007, Cave and Ellis wrote the soundtrack for the feature documentary The English Surgeon. The duo also provided original music for The Road in 2009 and the soundtrack for the audiobook of Cave's novel The Death of Bunny Munro.^[19]

Most recently, his song "Up Jumped the Devil" was featured in the Remedy-developed 2010 video game Alan Wake.

Cave's song "O Children" was featured in the 2010 movie, though not in the official soundtrack, of Harry Potter and the Deathly Hallows - Part 1.

Work with other artists[link]

Nick Cave has also played with Shane MacGowan, in a cover version of Bob Dylan's "Death is Not the End", and Louis Armstrong's "What a Wonderful World". Cave has also performed "What a Wonderful World" live with The Flaming Lips. Cave recorded a cover version of the Pogues song "Rainy Night in Soho", written by MacGowan.

Nick Cave at a solo concert in Mainz, Germany on 11 November 2006.

MacGowan also sings a version of "Lucy", released on B-Sides and Rarities. On 3 May 2008, during the Dig, Lazarus, Dig!!! tour Shane MacGowan joined Nick Cave and The Bad Seeds on stage to perform "Lucy" at Dublin Castle in Ireland. Pulp's single "Bad Cover Version" includes on its B-side a cover version by Cave of that band's song "Disco 2000". On the Deluxe Edition of Pulp's Different Class another take of this cover can be found.

In 2000, one of Cave's heroes, Johnny Cash, covered Cave's "The Mercy Seat" on the album American III: Solitary Man, seemingly repaying Cave for the compliment he paid by covering Cash's "The Singer" (originally "The Folk Singer") on his Kicking Against the Pricks album. Cave was then invited to be one of many rock and country artists to contribute to the liner notes of the retrospective The Essential Johnny Cash CD, released to coincide with Cash's 70th birthday. Subsequently, Cave cut a duet with Cash on a version of Hank Williams' "I'm So Lonesome I Could Cry" for Cash's American IV: The Man Comes Around album (2002). A similar duet, the American folk song "Cindy", was released posthumously on the "Johnny Cash: Unearthed" boxset. Cave's song "Let the Bells Ring" is a posthumous tribute to Cash. Cave has also covered the song "Wanted Man" which is best known as performed by Johnny Cash but is a Bob Dylan composition.

In 2004, Cave gave a hand to Marianne Faithfull on the album, Before the Poison. He co-wrote and produced three songs ("Crazy Love", "There is a Ghost" and "Desperanto"), and the Bad Seeds are featured on all of them. He is also featured on "The Crane Wife" (originally by The Decemberists), on Faithfull's 2008 album, Easy Come, Easy Go.

Cave collaborated with the band Current 93 on their album All the Pretty Little Horses, where he sings the title track, a lullaby. For his 1996 album Murder Ballads, Cave recorded "Where The Wild Roses Grow" with Kylie Minogue, and "Henry Lee" with P.J. Harvey.

Cave also took part in the "X-Files" compilation CD with some other artists, where he reads parts from the Bible combined with own texts, like "Time Jesum...", he outed himself as a fan of the series some years ago, but since he does not watch much TV, it was one of the only things he watched. He collaborated on the 2003 single "Bring It On", with Chris Bailey, formerly of the Australian punk group, The Saints. Cave contributed vocals to the song "Sweet Rosyanne", on the 2006 album Catch That Train! from Dan Zanes & Friends, a children's music group.

In 2011, Cave recorded a cover of the Zombies' "She's Not There" with Neko Case, which was used at the end of the first episode of the fourth season of True Blood.

Literary career[link]

Cave released his first book, King Ink, in 1988. It is a collection of lyrics and plays, including collaborations with Lydia Lunch. In 1997, he followed up with King Ink II, containing lyrics, poems, and the transcript of a radio essay he did for the BBC in July 1996, "The Flesh Made Word," discussing in biographical format his relationship with Christianity.

Cave reading from The Death of Bunny Munro in New York City, 2009.

While he was based in West Berlin, Cave started working on what was to become his debut novel, And the Ass Saw the Angel (1989). Significant crossover is evident between the themes in the book and the lyrics Cave wrote in the late stages of the Birthday Party and the early stage of his solo career. "Swampland", from Mutiny, in particular, uses the same linguistic stylings ('mah' for 'my', for instance) and some of the same themes (the narrator being haunted by the memory of a girl called Lucy, being hunted like an animal, approaching death and execution). On 21 January 2008, a special edition of Cave's novel And the Ass Saw the Angel was released.^[20] Cave's second novel The Death of Bunny Munro was published on 8 September 2009 by Harper Collins books.^[21][22] It tells the story of a sex-addicted salesman, was also released as a binaural audio-book produced by British Artists Iain Forsyth and Jane Pollard and an iPhone app.^[23] The book originally started as a screenplay Cave was going to write for John Hillcoat.^[24]

As proof of his interest in scripture, so evident in his lyrics and his prose writing, Cave wrote the foreword to a Canongate publication of the Gospel according to Mark, published in the UK in 1998. The American edition of the same book (published by Grove Press) contains a foreword by the noted American writer Barry Hannah.

Cave and Ellis composed scores for a production by the Icelandic theatre company Vesturport of Woyzeck by Georg Büchner, performed at the Barbican Theatre in the Barbican Arts Centre in London in 2005,^[25] and a stage adaptation of Franz Kafka's The Metamorphosis at the Lyric Hammersmith in London in 2006.^[26]

Cave is a contributor to the 2009 rock biography on The Triffids Vagabond Holes: David McComb and the Triffids, edited by Australian academics Niall Lucy and Chris Coughran.^[27]

Acting and screenwriting[link]

Cave has made occasional appearances as an actor, most prominently in the 1989 film Ghosts ... of the Civil Dead, written and directed by John Hillcoat, and in the 1991 film Johnny Suede with Brad Pitt.