1A seed vessel or seed case of a plant, especially a dehiscent capsule.
The receptacle in a seed drill or sowing-machine which contains the seed.
3A container used for growing plants from seed until they are fit for transplantation.
4US Any of several North American perennial aquatic plants of the genus Ludwigia (family Onagraceae), especially L. alternifolia, which has bright yellow flowers, lanceolate leaves, and cubical seed capsules.
Late 17th century; earliest use found in Robert Hooke (1635–1703), natural philosopher. From seed + box.