Seed Anatomy (Plant Science 20L)

Epicotyl

The epicotyl is the embryonic shoot above the cotyledons. In dicots, the hypocotyl is what appears to be the base stem under the spent withered cotyledons, and the shoot just above that is the epicotyl. In monocot plants, the first shoot that emerges from the ground or from the seed is the epicotyl, from which the first shoots and leaves emerge.

Gymnosperms

The gymnosperms are a group of seed-producing plants that includes conifers, cycads, and Gingko. The term "Gymnosperm" comes from the Greek word gymnospermos, meaning "naked seeds".

Hypocotyl

The hypocotyl ( short for hypocotyledonous stem", [1] meaning "below seed leaf") is the stem of a germinating seeding, found below the cotyledons (seed leaves) and above the radicle (root).

Seed Coat

The outer covering of the seed.

Radicle

The radicle is the first part of a seeding (a growing plant embryo) to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil (the shoot emerges from the plumule).

Plumule

The rudimentary terminal bud of a plant embryo situated at the end of the hypocotyl, consisting of the epicotyl and often of immature leaves.

Hilum

The scar on a seed, such as a bean, indicating the point of attachment to the funiculus.

Pericarp

The wall of a ripened ovary; fruit wall

Hypogeous

Where the cotyledons remain non-photosynthetic, inside the seed shell, and below ground, is hypogeal.

Monocotyledon

monocots, are one of two major groups of flowering plants (or angiosperms) that are traditionally recognized, the other being cotyledons, or dicots. Monocot seedings typically have one cotyledon (seed-leaf).

Coleorhiza

A sheath-like structure found in a plant seed that connects the coleoptile to the primary root and acts as a protective covering enclosing the plumule and radicle.

Embryo

An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination.

Gibberellins

(GAs) are plant hormones that regulate growth and influence various developmental processes, including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction, and leaf and fruit senescence.

Cotyledon

A cotyledon; "seed leaf" is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seeding. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants (angiosperms). Species with one cotyledon are called monocotyledonous ("monocots"). Plants with two embryonic leaves are termed dicotyledonous ("dicots").

Micropyle

A minute opening in the ovule of a seed plant through which the pollen tube usually enters.

Epigeous

A seed is described as epigeal when the cotyledons of the germinating seed expand, throw off the seed shell and become photosynthetic above the ground.

Angiosperms

Angiosperms means a plant that produces seeds within an enclosure; they are fruiting plants, although more commonly referred to as flowering plants. Characteristics include flowers, endosperm within the seeds, and the production of fruits that contain the seeds.

Dicotyledon

Dicotyledons, also known as dicots, was a grouping formerly used for the flowering plants whose seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group. [1] Flowering plants that were not dicotyledons were called monocotyledons, typically having one embryonic leaf.

Embryogenesis

Embryogenesis is the process that produces a plant embryo from a fertilized ovule by asymmetric cell division and the differentiation of undifferentiated cells into tissues and organs. It occurs during seed development, when the single-celled zygote undergoes a programmed pattern of cell division resulting in a mature embryo.

Endosperm

Endosperm is the tissue produced inside 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 oils and protein.

Coleoptile

Is the pointed protective sheath covering the emerging shoot in monocotyledons such as oats and grasses.