Our ‘A’ to ‘Z’ of Gardening Terms

Terms that begin with “E”

ecologyThe science of relationships between organisms and their environment.
economic thresholdThe level at which pest damage justifies the cost of control. In home gardening, the threshold may be aesthetic rather than economic.
eggA female sex cell.
emasculateTo remove a flower’s anthers.
embryoThe dormant, immature plant within a seed, the “germ” referred to in wheat germ.
embryo cultureSee tissue culture.
enationEpidermal outgrowths on leaves or stems.
endodermisA layer of cells in roots between the cortex and the vascular tissues.
endospermThe nutritive tissue within the seed of a flowering plant. Surrounds and is absorbed by the embryo.
enzymeA biological catalyst that aids in a specific biochemical process, such as converting food from one form to another.
epidermal hairA filament of cells arising from an epidermal cell.
epidermisThe outermost layer of cells covering a plant’s leaves, roots, and young parts.
epigeous germinationSeed germination in which the cotyledons are raised above the soil surface.
epinastyAn abnormal downward-curving growth or movement of a leaf, leaf part, or stem.
epiphyteA plant growing on another plant for support.
espalierThe training of a tree or shrub to grow flat on a trellis or wall. Espalier patterns may be very precise and formal or more natural and informal.
etiolationDevelopment of yellow, long, spindly growth on a plant as a result of insufficient light.
ethyleneA gaseous plant hormone (C2H4) produced in abundance by ripening fruits and damaged tissues.
etiolationThe condition where a plant is grown in darkness, resulting in pale and elongated stems and underdeveloped leaves.
evergreenA plant that never loses all of its foliage at the same time.
exciseTo remove or extract, as an embryo from a seed or ovule.
excurrentA tree form in which the main trunk remains dominant with small, more or less horizontal branches. Fir and sweetgum are examples.
exfoliatingPeeling off in shards or thin layers, as in bark from a tree.
exoskeletonThe outer support structure of an insect.