Leaf epinasty induced by reflection of light from beneath marigold plants

The cotyledons of marigold, Tagetes erecta L., developed epinasty when refl ective surfaces were maintained under the seedlings. Plain aluminum foil or white-painted foil induced up to 360 degrees curvature as the cotyledons e xtended, whereas no epinasty occurred over the exposed surface of potting m ix or black-painted foil. A gray-painted foil induced intermediate epinasty , Dry-weight accumulation of the seedlings was not significantly affected b y the epinasty.