Glossary of Botanical Terms - E

E

ecological amplitude

the range of environmental conditions in which an organism can survive.

elaisome

oily body attached to the seed.

ellipsoid

a 3-dimensional shape, elliptical in all sections through the long-axis.

elliptical (elliptic)

planar, shaped like a flattened circle, symmetrical about both the long and the short axis; about twice as long as broad, tapering equally both to the tip and the base; oval.

emarginate

notched at apex (notch usually broad and shallow).

embryo

young plant contained by a seed.

enantiostyly

the condition in which the gynoecium protrudes laterally, to the right (dextrostyly) or to the left (sinistrostyly) of the androecium. example: Senna.

endemic

having a natural distribution restricted to a particular geographic region; cf. native.

endocarp

the innermost layer of the wall of a fruit; in a drupe, the stony layer surrounding the seed.

endosperm

nutritive tissue in a seed; albumen.

ensiform

shaped like the blade of a sword.

entire

1. not divided.

2. (of a margin) having a smooth margin, not lobed or toothed (it may be wavy or scalloped).

ephemeral

short-lived.

epicalyx

an involucre resembling an outer calyx; e.g. as seen in Hibiscus.

epicarp

the outer layer of the wall of a fruit, i.e. the 'skin'.

epicormic

said of buds shoots or flowers developing from the old wood of trees, especially after injury or fire.

epicotyl

the part of the plant axis or stem between the cotyledonary node and first foliage leaves.

epidermis

an organ's outermost layer of cells, usually only one cell thick.

epigynous

borne on the ovary; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall; cf. hypogynous, perigynous.

epilithic

growing on stone; compare lithophytic, a plant growing on stone.

epipetalous

of stamens that are attached to the petals.

epiphytic

see lithophytic.

epitepalous

of stamens that are attached to the tepals.

epiphyte

(adjective epiphytic) one plant growing on another without deriving nourishment from it (in other words, not parasitic); compare parasite. Loosely, and incorrectly, applied to plants that are not terrestrial (they may grown on various inorganic or organic surfaces), and often to orchids, which are rock-dwelling (and therefore strictly lithophytic).

epithet

the adjectival component in a binomial; final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon.

equitant

of a leaf when folded lengthwise with edges adhering except at the base, where it clasps another leaf on the opposite side of the stem.

erect

upright, more or less perpendicular to the ground or point of attachment.

ericoid

with leaves like the European heath (Erica), small and sharply pointed.

erose

with the margin irregular as though nibbled or worn away.

even-pinnate

having an even number of leaflets in a compound leaf, = paripinnate.

evergreen

not deciduous, having leaves all the year round.

ex

in nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name. See Author citation (botany).

exocarp

the outer layer of the pericarp, often the skin of fleshy fruits.

exotesta

the outer layer of the testa (seed coat). It is derived from the outer integument of the ovule.

exotic

not native; introduced from another region or country.

exserted

projected beyond, e.g. the stamens beyond the corolla tube.

exstipulate

without stipules.

extrastaminal

outside the stamens or androecium, usually referring to the location of a nectary disk.

extrorse

of anther locules, opening towards the outside of the flower; cf. introrse, latrorse.