epidermis. The outermost layer or part of the cortex; the skin.

epigeal. Said of seeds (as common bean) in which the cotyledons or seed-leaves rise above ground in germination. See [hypogeal].

epiphyte. A plant that grows on another plant, or on other objects above ground, but which does not derive much or any of its nourishment from its host; an air-plant.

excurrent. Said of trees (as firs and spruces) in which the main trunk or leader continues through the tree top.

exogen (see [endogen]). Of the dicotyledon class, the stem enlarging by external layers or rings.

fertilization takes place in the flower when a pollen nucleus and an egg-cell nucleus unite in a forming ovule.

fibro-vascular. Bundles or strands of tissue composed of sieve-tubes, mechanical fibre and vessels or ducts.

filament. The stalk part of a stamen.

follicle. A single-cavity fruit or pod opening along its inner edge.

frond. A leaf of a fern and related plants.