hydrotropism Bot.
(haɪˈdrɒtrəpɪz(ə)m)
[f. as hydrotropic a. + -ism.]
The property, exhibited by the growing parts (esp. the roots) of plants, of bending or turning under the influence of moisture. Cf. heliotropism.
| 1882 F. Darwin in Nature 27 Apr. 600 Hydrotropism,—Roots have the power of bending towards a wet surface. 1897 Willis Flower. Pl. I. 21 The root will be deflected toward the damp side, or..will exhibit positive hydrotropism. |