The Collaborative International Dictionary
Coleorhiza
Coleorhiza \Co`le*o*rhi"za\, n. [NL., fr. Gr. ? sheath + ?
root.]
A sheath in the embryo of grasses, inclosing the caulicle.
--Gray.
Wiktionary
coleorhiza
n. A sheath-like structure found in a plant seed that connects the coleoptile to the primary root and acts as a protective covering enclosing the plumule and radicle.