In botany, a seed is a plant embryo and food reserve enclosed in a protective outer covering called a seed coat (testa). More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted.
Phoenix dactylifera, commonly known as the date palm, is a flowering-plant species in the palm family, Arecaceae, cultivated for its edible sweet fruit called dates. The species is widely cultivated across northern Africa, the Middle East, and South Asia, and is naturalized in many tropical and subtropical regions worldwide. P. dactylifera is the type species of genus Phoenix, which contains 12–19 species of wild date palms.
A seed bank stores seeds to preserve genetic diversity; hence it is a type of gene bank. There are many reasons to store seeds. One is to preserve the genes that plant breeders need to increase yield, disease resistance, drought tolerance, nutritional quality, taste, etc. of crops. Another is to forestall loss of genetic diversity in rare or imperiled plant species in an effort to conserve biodiversity ex situ. Many plants that were used centuries ago by humans are used less frequently now; seed banks offer a way to preserve that historical and cultural value. Collections of seeds stored at constant low temperature and low moisture are guarded against loss of genetic resources that are otherwise maintained in situ or in field collections. These alternative "living" collections can be damaged by natural disasters, outbreaks of disease, or war. Seed banks are considered seed libraries, containing valuable information about evolved strategies to combat plant stress, and can be used to create genetically modified versions of existing seeds. The work of seed banks often span decades and even centuries. Most seed banks are publicly funded and seeds are usually available for research that benefits the public.
Recalcitrant seeds are seeds that do not survive drying and freezing during ex situ conservation. By and large, these seeds cannot resist the effects of drying or temperatures less than 10 °C ; thus, they cannot be stored for long periods like orthodox seeds because they can lose their viability. Plants that produce recalcitrant seeds include avocado, mango, mangosteen, lychee, cocoa, rubber tree, some horticultural trees, aquatic plants such as Nymphaea caerulea, and several plants used in traditional medicine, such as species of Virola and Pentaclethra. Generally speaking, most tropical pioneer species have orthodox seeds but many climax species have recalcitrant or intermediate seeds.
Legumes are plants in the family Fabaceae, or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consumption; for livestock forage and silage; and as soil-enhancing green manure. Well-known legumes include beans, soybeans, chickpeas, peanuts, lentils, lupins, grass peas, mesquite, carob, tamarind, alfalfa, and clover. Legumes produce a botanically unique type of fruit – a simple dry fruit that develops from a simple carpel and usually dehisces on two sides.
In botany, a perennial plant or simply perennial is a plant that lives more than two years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials. Notably, it is estimated that 94% of plant species fall under the category of perennials, underscoring the prevalence of plants with lifespans exceeding two years in the botanical world.
Fremontodendron, with the common names fremontia and flannelbush or flannel bush, is a genus of three known species of shrubs native to the Southwestern United States and northwest Mexico.
Tribulus terrestris is an annual plant in the caltrop family (Zygophyllaceae) widely distributed around the world. It is adapted to thrive in dry climate locations in which few other plants can survive.
Taxodium distichum is a deciduous conifer in the family Cupressaceae. It is native to the southeastern United States. Hardy and tough, this tree adapts to a wide range of soil types, whether wet, salty, dry, or swampy. It is noted for the russet-red fall color of its lacy needles.
Sanguisorba minor, the salad burnet, garden burnet, small burnet, burnet, pimpernelle, Toper's plant, and burnet-bloodwort, is an edible perennial herbaceous plant in the family Rosaceae. It has ferny, toothed-leaf foliage; the unusual crimson, spherical flower clusters rise well above the leaves on thin stems. It generally grows to 25–55 cm tall. The large, long, taproots store water, making it drought-tolerant.
The Judean date palm is a date palm grown in Judea. It is not clear whether there was ever a single distinct Judean cultivar, but dates grown in the region have had distinctive reputations for thousands of years, and the date palm was anciently regarded as a symbol of the region and its fertility. Cultivation of dates in the region almost disappeared after the 14th century AD from a combination of climate change and infrastructure decay but has been revived in modern times.
Rhus typhina, the staghorn sumac, is a species of flowering plant in the family Anacardiaceae, native to eastern North America. It is primarily found in southeastern Canada, the northeastern and midwestern United States, and the Appalachian Mountains, but it is widely cultivated as an ornamental throughout the temperate world. It is an invasive species in some parts of the world.
Gene banks are a type of biorepository that preserves genetic material. For plants, this is done by in vitro storage, freezing cuttings from the plant, or stocking the seeds. For animals, this is done by the freezing of sperm and eggs in zoological freezers until further need. With corals, fragments are taken and stored in water tanks under controlled conditions. Genetic material in a 'gene bank' is preserved in a variety of ways, such as freezing at -196 °C in liquid nitrogen, being placed in artificial ecosystems, or put in controlled nutrient media.
The soil seed bank is the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lake. The first scientific paper on the subject was published in 1882 and reported on the occurrence of seeds at different soil depths. Weed seed banks have been studied intensely in agricultural science because of their important economic impacts; other fields interested in soil seed banks include forest regeneration and restoration ecology.
There have been several seeds known at different times as the oldest viable seed.
Salix scouleriana is a species of willow native to northwestern North America. Other names occasionally used include fire willow, Nuttall willow, mountain willow, and black willow.
Hordeum pusillum, also known as little barley, is an annual grass native to most of the United States and southwestern Canada. It arrived via multiple long-distance dispersals of a southern South American species of Hordeum about one million years ago. Its closest relatives are therefore not the other North American taxa like meadow barley or foxtail barley, but rather Hordeum species of the Pampas of central Argentina and Uruguay. It is less closely related to the Old World domesticated barley, from which it diverged about 12 million years ago. It is diploid.
Tamarix chinensis is a species of tamarisk known by the common names five-stamen tamarisk and Chinese tamarisk or saltcedar. It is native to China and Korea, and it is known in many other parts of the world as an introduced species and sometimes an invasive noxious weed. It easily inhabits moist habitat with saline soils. It may grow as a tree with a single trunk or as a shrub with several spreading erect branches reaching 6 metres or more in maximum height. It has been known to reach 12 metres. It has reddish, brown, or black bark. The small, multibranched twigs are covered in small lance-shaped, scale-like leaves which are no more than about 3 mm long. The inflorescence is a dense raceme of flowers a few cm long. Each fragrant flower has five petals which are usually pink but range from white to red.
Danthonia spicata is a species of grass known by the common name poverty oatgrass, or simply poverty grass. It is native to North America, where it is widespread and common in many areas. The species is distributed across much of Canada and the United States, and its distribution extends into northern Mexico.
Ribes oxyacanthoides is a species of flowering plant in the gooseberry family known by the common name Canadian gooseberry. Its various subspecies have common names of their own. It is native to North America, where it occurs in Alaska through much of Canada and the western and north-central United States.
