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the growth of plant organs at some angle in the direction of a stimulus (for example, the force of gravity or a light source). Lateral shoots and roots, rhizomes, and leaves are plagiotropic. Plagiotropic organs usually are bilaterally symmetrical in structure. The angle of inclination is not absolutely constant in magnitude and may change, depending on the conditions under which the plant is growing. (See also ORTHOTRO-PISM.)