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.