E

Ecotype: Individuals which are interfertile with each other and members of other ecotypes of the same species, but maintain their individuality through environmental isolation and selection.

Deaphic: Pertaining to, or influenced by, soil conditions.

Egg: The female gamete or germ cell.

Elliptic: Oval in outline with rounded ends and widest about the middle.

Emarginate: Notched at the extremity.

Emasculate: To remove the anthers from a bud or flower before the pollen is shed.

Embryo: The rudimentary plant still enclosed in the seed which arises from the zygote.

Embryo sac: The female gametophyte typically with 8 nuclei.

Endemic: Confined to a region or country and not native anywhere else.

Endocarp: The innermost layer of the pericarp or fruit wall.

Endosperm: The starchy of oily nutritive material stored within some seeds, sometimes referred to as albumen; it is triploid, having arisen from the triple fusion of a sperm nucleus and the two polar nuclei of the embryo sac.

Ensiform: Sword-shaped.

Entire: An even margin without teeth, lobes, etc.

Entomophilous: Insect-pollinated.

Ephemeral: Plant with a short life-cycle, producing several generations in a year; flowers persisting for one day only.

Epicalyx: An involucre of bracts below the flower resembling an extra calyx.

Epigeal: Above ground; in epigeal germination the cotyledons are raised above the ground.

Epigynous: When the sepals, petals and stamens are borne above an inferior ovary.

Epipetalous: On the petals.

Epiphyte: A plant which grows on another plant but without deriving nourishment from it.

Epiphytotic: Sudden and widespread development of a destructive plant disease.

Escape: A plant growing away from cultivation, but not well naturalized.

Exalbuminous: Without endosperm or albumen.

Exocarp: The outer layer of the pericarp or fruit wall.

Exserted: Projecting beyond, as stamens from a perianth.

Exstipulate: Without stipules.

Extra-axillary: Beyond or outside the axil.

Extra-floral: Away from the flower.

Extrorse: An anther which dehisces outwardly towards the perianth.

Eye: The marked centre of a flower; a bud on a tuber; a single-bud cutting. 

F

F₁, F₂, etc.: Symbols used to designate the first generation, second generation, etc., after a cross.

Facultative: Occasional or incidental.

Falcate: Sickle-shaped.

Farinaceous: Containing starch or starch like materials.

Farinose: Covered with a meal-like powder.

Fasciation: A malformation of stems resulting in enlargement and flattening.

Fascicle: A cluster of flowers, leaves, etc., arising from the same point.

Ferruginous: Rust-coloured.  

Fertilization: Union of the gametes (egg and sperm) to form a zygote.

Filament: Thread; the stalk of a stamen supporting the anther.

Filiform: Slender; threadlike.

Fimbriate: Fringed.

Flabellate: Fanlike.

Flexuose: Zigzag; bent alternately in opposite directions.

Floccose: Covered with woolly hairs. 

Floret: Individual small flower, as in grasses and composites.

Foliaceous: Leaf-like.

Follicle: Dry dehiscent fruit composed of a single carpel.

Free: Neither adhering nor united.  

Fruit: The ripened ovary with adnate parts.

Frutescent, Fruticose: Shrubby.

Fugacious: Falling off early.

Funicle: The little cord which attaches the ovule to the placenta.

Furcate: Forked.

Fusiform: Spindle-shaped; tapering at each end from a swollen middle. 

G

Gamete: Sexual protoplasmic body (egg or sperm), which unites with another for reproduction.

Gamopetalous: With united petals either throughout their length or at the base.

Gamosepalous: With united sepals.

Gene: The unit of inheritance located on the chromosome.

Genetics: The science dealing with heredity.

Geniculate: Bent like a knee.

Genome: A set of chromosomes as contained within the gamete and corresponds to the haploid chromosome number of the species.

Genotype: The genetic make-up of an organism comprising the sum total of its genes, both dominant and recessive; a group of organisms with the same genetic makeup.

Geophilous: On or from the ground.

Glabrescent: Becoming glabrous or nearly so.

Glabrous: Devoid of hairs.

Glandular: Having or bearing secreting organs or glands.

Glaucous: Pale bluish green, or with a whitish bloom which rubs off.

Globose: Spherical or nearly so.

Glomerate: Compactly clustered.

Glumes: The lower two sterile bracts at the base of grass spikelets.

Glutinous: Sticky.

Gynaecium: The female part or pistil of a flower, consisting, when complete, of one or more ovaries with their styles and stigmas.

Gynophore: A stalk supporting the gynaecium formed by elongation of the receptacle prolonged within the perianth. 

H

Halophyte: A plant tolerant of certain mineral salts, particularly sodium chloride, in the soil solution.

Haploid: Having a single set (genome) of chromosomes in a cell or an individual, or the reduced number (n) as in a gamete.

Hastate: With more or less triangular basal lobes diverging laterally.

Haustorium: An absorbing organ, as in a parasitic plant.

Herb: Any vascular plant which is not woody.

Herbaceous: Not woody.

Heritability: That portion of the observed variance in a progeny that is inherited.

Hermaphrodite: Bisexual; in flowers with stamens and pistil in the same flower.

Heterogamous: With two or more kinds or forms of flowers.

Heterogeneous: Lacking in uniformity; exhibiting variability.

Heterosis: Increase in vigour, growth or yield of a hybrid progeny in relation to the average of the parents; hybrid vigour.

Heterostylous: Having styles of two or more distinct forms or of different lengths.

Heterozygous: Having unlike alleles at corresponding loci of homologous chromosomes; an organism can be heterozygous for one or several genes.

Hexaploid: Having six sets of chromosomes (6n).

Hilum: The scar left on a seed indicating its point of attachment.

Hirsute: With rather coarse stiff hairs.

Hispid: Covered with bristly hairs.

Homogamous: When the anthers and stigmas mature simultaneously; when the flower head has all the flowers of the same kind.   

Homogeneous: Uniform as to kind; showing no variability.

Homologous chromosomes: Chromosomes which pair at the first division in meiosis; each member of a pair has a corresponding sequences of gene loci and is derived from a different parent.

Homozygous: Having like genes at corresponding loci on homologous chromosomes; an organism may be homozygous for one, several, or all genes.

Husk: The outer covering of some fruits.

Hyaline: Almost transparent.

Hybrid: The first generation offspring of a cross between two individuals differing in one or more genes.

Hybridization: The crossing of individuals of unlike genetic constitution.

Hydrophyte: Plant growing in water or swamps.

Hypanthium: The cup-like receptacle usually derived from the fusion of the floral envelopes and androecium on which are seemingly borne the calyx, corolla and stamens.

Hypocotyl: The part of the axis below the cotyledons in a seedling.

Hypogeal: Below ground; in hypogeal germination the cotyledons remain below ground within the testa.

Hypogynous: Petals and stamens inserted on the receptacle below a superior ovary and free from it.