from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A protective sheath enclosing the embryonic root of grasses.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- 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.
from the GNU version of the Collaborative International Dictionary of English
- n. A sheath in the embryo of grasses, inclosing the caulicle.
from The Century Dictionary and Cyclopedia
- n. In the embryo of many endogenous plants, the sheath covering the root, which bursts through it in germination.
The sheath which envelopes the radicle is called = coleorhiza = and that of the plumule, = pileole = or = germ-sheath =.