资料来源 : pyDict

向日性,屈日性

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Heliotropism \He`li*ot"ro*pism\, n. [Helio- + Gr. ? to turn.]
   (Bot.)
   The phenomenon of turning toward the light, seen in many
   leaves and flowers.

资料来源 : WordNet®

heliotropism
     n : an orienting response to the sun