the world > plants > part of plant > part defined by form or function > [adjective] > sheathing (4)
In sense 5, as socket-leaf; socket-leaved, socket-eyed adjs.
Of a part of a plant, esp. a leaf: forming a sheath; = sheathing, adj. b. Cf. vagina, n. 2b.
Botany. Designating a sheath enclosing a stem, petiole, or other part of a plant; enclosed in such a sheath; (occasionally) forming such a sheath…