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A cotyledon ("seed leaf" from Greek
Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
: ??t???d?? kotyledon, from ??t??? kotıle
Cotyla

In classical antiquity, the cotyla or cotyle was a measure of capacity among the Ancient Romans and Ancient Greeks: by the former it was also called hemina; by the latter, and or ....
, "cup, bowl") is a significant part of the embryo
Embryo

An embryo is a multicellular organism ploidy eukaryote in its earliest stage of development, from the time of first cell division until birth, Egg , or germination....
 within the seed
Seed

A seed is a small Plant embryogenesis plant enclosed in a covering called the seed coat, usually with some Food storage. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant....
 of a plant
Plant

Plants are Life organisms belonging to the Kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae....
.






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Cotyledon Cercis Siliquastrum
Monocot Vs Dicot Crop Pengo
A cotyledon ("seed leaf" from Greek
Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
: ??t???d?? kotyledon, from ??t??? kotıle
Cotyla

In classical antiquity, the cotyla or cotyle was a measure of capacity among the Ancient Romans and Ancient Greeks: by the former it was also called hemina; by the latter, and or ....
, "cup, bowl") is a significant part of the embryo
Embryo

An embryo is a multicellular organism ploidy eukaryote in its earliest stage of development, from the time of first cell division until birth, Egg , or germination....
 within the seed
Seed

A seed is a small Plant embryogenesis plant enclosed in a covering called the seed coat, usually with some Food storage. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant....
 of a plant
Plant

Plants are Life organisms belonging to the Kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae....
. Upon germination
Germination

Germination is the process whereby growth emerges from a period of dormancy. The most common example of germination is the sprouting of a seedling from a seed of an flowering plant or gymnosperm....
, the cotyledon may become the embryonic first leaves
Leaf

In botany, a leaf is an above-ground plant Organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin, to expose the cells containing chloroplast to light over a broad area, and to allow light to penetrate fully into the tissues....
 of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plant
Flowering plant

The flowering plants or angiosperms are the most widespread group of Embryophytes. The flowering plants and the gymnosperms are the only extant groups of Spermatophyte....
s (angiosperms). Species with one cotyledon are called monocotyledonous (or, "monocots") and placed in the class Liliopsida
Liliopsida

Liliopsida is a botanical name for the Class containing the Family Liliaceae . It is considered synonymous with the name monocotyledon. Publication of the name is credited to Scopoli : see author citation ....
. Plants with two embryonic leaves are termed dicotyledonous ("dicots") and placed in the class Magnoliopsida
Magnoliopsida

Magnoliopsida is a valid botanical name for a class of flowering plants. By definition the class will include the family Magnoliaceae, but its wiktionary:circumscription can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed....
.

The cotyledon of grasses
Poaceae

Poaceae or Gramineae is a family in the Class Liliopsida of the Magnoliophyta. Plants of this family are usually called grasses; the shrub- or tree-like plants in this family are called bamboo ....
 and many other monocotyledons is highly modified leaf composed of a scutellum
Scutellum (botany)

The scutellum is part of the structure of a barley seed - the modified seed leaf.The scutellum can also refer to the equivalence of a thin cotyledon in monocots ....
 and a coleoptile
Coleoptile

Coleoptile is the pointed protective sheath covering the emerging shoot in cotyledon such as oats and grasses. Coleoptiles have two vascular bundles, one on either side....
. The scutellum is a tissue within the seed that is specialized to absorb stored food from the adjacent endosperm
Endosperm

Endosperm is the tissue produced in the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain Vegetable oils and protein....
. The coleoptile is a protective cap that covers the plumule (precursor to the stem and leaves of the plant).

Gymnosperm
Gymnosperm

Gymnosperm is a group of spermatophyte seed-bearing plants with ovules on scales, which are usually arranged in cone-like structures. The other major group of seed-bearing plants, the angiosperms, [from the Greek, 'angion' - container] have ovules enclosed in a carpel, a sporophyll with fused margins....
 seedlings also have cotyledons, and these are often variable in number (multicotyledonous), with from 2 to 24 cotyledons forming a whorl at the top of the hypocotyl
Hypocotyl

Hypocotyl is a Botany term for a part of a germination seedling of a seed plant. As the plant embryo grows at germination, it sends out a shoot called a radicle that becomes the primary root and penetrates down into the soil....
 (the embryonic stem) surrounding the plumule. Within each species, there is often still some variation in cotyledon numbers, e.g. Monterey Pine
Monterey Pine

Pinus radiata is known in English as Monterey Pine in some parts of the world , and Radiata Pine in others .It is a species of pine native to coastal California in three very limited areas in Santa Cruz County, California, Monterey County, California and San Luis Obispo County, California Counties, and on Guadalupe Island...
 (Pinus radiata) seedlings have 5–9, and Jeffrey Pine
Jeffrey Pine

Jeffrey Pine , named in honor of its documenter John Jeffrey , is a North American pine related to Ponderosa Pine. It occurs from southwest Oregon south through much of California , to northern Baja California in Mexico....
 (Pinus jeffreyi) 7–13 (Mirov 1967), but other species are more fixed, with e.g. Mediterranean Cypress
Cupressus sempervirens

Cupressus sempervirens, the Mediterranean Cypress is a species of Cupressus native to the eastern Mediterranean region, in northeast Libya, southeast Greece , southern Turkey, Cyprus, western Syria, Lebanon, Israel and western Jordan, and also a disjunct population in Iran....
 always having just two cotyledons. The highest number reported is for Big-cone Pinyon
Big-cone Pinyon

Big-cone Pinyon is a pine in the pinyon pine group, native to central Mexico. The range is highly localised, confined to a small area of the southern Sierra Madre Occidental in southern Zacatecas....
 (Pinus maximartinezii), with 24 (Farjon & Styles 1997).
The cotyledons may be ephemeral, lasting only days after emergence, or persistent, enduring a year or more on the plant. The cotyledons contain (or in the case of gymnosperms and monocotyledons, have access to) the stored food reserves of the seed
Seed

A seed is a small Plant embryogenesis plant enclosed in a covering called the seed coat, usually with some Food storage. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant....
. As these reserves are used up, the cotyledons may turn green and begin photosynthesis
Photosynthesis

File:Seawifs global biosphere.jpgPhotosynthesis is a metabolic pathway that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight....
, or may wither as the first true leaves take over food production for the seedling.

Cotyledons may be either epigeal
Epigeal

Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface.In botany, a seed is described as epigeal when the cotyledons of the germinate seed expand, throw off the seed shell and become photosynthesis above the ground....
, expanding on the germination of the seed, throwing off the seed shell and become photosynthetic above the ground; or hypogeal
Hypogeal

Hypogeal means "underground".* In botany, a seed is described as hypogeal when the cotyledons of the germinate seed remain photosynthesis, inside the seed shell, and below ground....
, not expanding, remaining below ground and not becoming photosynthetic. The latter is typically the case where the cotyledons act as a storage organ, as in many nuts
Nut (fruit)

Nut is a general term for the large, dry, oily seed or fruit of some plant. While a wide variety of dried seeds and fruits are called nuts, only a certain number of them are considered by biologists to be true nuts....
 and acorn
Acorn

The acorn, or oak nut, is the nut of the oak tree . It is a nut , containing a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule....
s.