The uppermost layers of soils consisting of partly decomposed plant remains and relatively fresh leaves and other plant debris; the surface mineral layer, high in organic matter and dark in color; and the lighter colored layer where leaching of solutes and suspended materials occurs.

Directed away from the stem of a plant; pertaining to the lower surface of a leaf

Spontaneous generation of life from nonliving material

Nonliving environmental factors such as frost, drought, excessive heat, high winds, etc., that can have harmful effects on plants.

Imperfect development or nondevelopment of an organ.

To scrape off.

A belt of tissue preparing for separation, especially at the connection of a leaf to the stem.abscission, fruit drop, and seed dormancy, and has an inhibitory effect on cell elongation

The area of separation when a plant sheds a leaf, flower or fruit.

To suck up or take up, e.g., plant roots absorb water.

A graph of the amount of light a substance absorbs, plotted as a function of energy, frequency, or wavelength.

Domatia which have adapted to provide shelter to beneficial mites.

Admixtures that decrease the setting time of concrete by increasing the rate of hydration.

Auxiliary, subsidiary; as the parts of a flower beyond the necessary male and female organs, such as petals and sepals.

A fruit, or group of fruits derived from a singleflower, in which the conspicuous, fleshy portion develops from the receptacle and is shed with the true fruit(s) attached

To adapt to a new environment, or a change in the environment

Gaining in girth or length with age or following fertilization, or growing together, as the calyx of some plants after flowering, such as the ground cherry

Shaped like a maple leaf; deeply lobed

A small dry and hard 1-celled, 1-seeded indehiscent fruit.

Any dry fruit that does not open by itself

Lacking chlorophyll; appearing without green color

1. Describes a surface that is etched with fine lines, as if scratched by a needle. 2. Marked with what appears to be pin pricks, usually arranged at random.

Soil with a pH below 7.

pH below 7

Slightly acidic.

Shaped like a half moon.