Seedling

A seedling is a young plant sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle (embryonic root), the hypocotyl (embryonic shoot), and the cotyledons (seed leaves). The two classes of flowering plants (angiosperms) are distinguished by their numbers of seed leaves: monocotyledons (monocots) have one blade-shaped cotyledon, whereas dicotyledons (dicots) possess two round cotyledons. Gymnosperms are more varied. For example, pine seedlings have up to eight cotyledons. The seedlings of some flowering plants have no cotyledons at all. These are said to be acotyledons.

Part of a seed embryo develops into the shoot, bearing the first true leaves of a plant. In most seeds, for example the sunflower, the plumule is a small conical structure without any leaf structure. Growth of the plumule does not occur until the cotyledons have grown above ground. This is epigeal germination. However, in seeds such as the broad bean, a leaf structure is visible on the plumule in the seed. These seeds develop by the plumule growing up through the soil with the cotyledons remaining below the surface. This is known as hypogeal germination.

Seedling (novel)

Seedling is the thirteenth book in the series of Deathlands. It was written by Laurence James under the house name James Axler.

Plot synopsis

A particularly rough MAT-TRANS jump takes Ryan Cawdor and his friends to a clean, almost immaculate arrival chamber. A cautious exploration of the nearby control room shows it to be similarly clean, free of dust or any form of decay. It is only when Doc Tanner discovers a cup of recently brewed, sweetened coffee that the companions realize the room may have been recently used. Instead of the usual blast doors, the room's exit appears to be some form of airlock; nearby readouts indicate the outside air pressure is very low. Ryan cautiously opens the exterior door in the hopes that the equipment is simply malfunctioning, only to pass out from a sudden drop in oxygen levels. J. B. Dix pulls him to safety before he succumbs, and shuts the airlock door. The demonstrated lack of atmosphere, combined with a lifeless desert view through the airlock portal and mention of "NASA-SEC" on warnings above it, lead all the companions to the same unstated conclusion: they are on another world. Seeing something through the portal that alarms him, Ryan orders his friends into the MAT-TRANS chamber to make another jump. When pressed for what prompted the reaction Ryan can only say he saw something gigantic and alive underneath the desert sand.

Seedling (disambiguation)

A seedling is young plant after germination from seeds (sometimes also referred to as sprouts).

Seedling may also refer to:

See also