trimorphism

Century Dictionary and Cyclopedia

1. n. In crystallography, the property of crystallizing in three fundamentally different forms. Titanium dioxid, TiO₂, is an example of trimorphism. In one form it is the mineral octahedrite or anatase; in another, rutile; in a third, brookite.
2. n. In biology, existence under three distinct forms. It is not rare among insects.
3. n. In botany, the occurrence of three distinct forms of flowers or other parts upon the same plant, or upon plants of the same species. In trimorphous flowers there are three sets of stamens and pistils, which may be called respectively long, middle, and short-length, and in which the pollen from the long stamens is capable of fertilizing only the long-styled forms, the mid-length stamens the mid-styled, etc. Compare dimorphism, and see heterogonaus trimorphism, under heterogonous.

GNU Webster's 1913

1. n. The property of crystallizing in three forms fundamentally distinct, as is the case with titanium dioxide, which crystallizes in the forms of rutile, octahedrite, and brookite. See pleomorphism.
2. n. The coëxistence among individuals of the same species of three distinct forms, not connected, as a rule, by intermediate gradations; the condition among individuals of the same species of having three different shapes or proportions of corresponding parts; -- contrasted with polymorphism, and dimorphism.