A thin membrane covering the sorus of a fern. The indusium often shrivels away when spores are ready to be dispersed. Also called fruitcover.
A cuplike structure fringed with hairs and located at the top of the style in flowers of the family Goodeniaceae (which includes the garden flowers lobelia and scaevola). Pollen is deposited into the indusium by the anthers of the same flower and, as the style grows, carried up for dispersal by pollinating insects.