• (a.) Having the radicle of the embryo lying against the back of one of the cotyledons; incumbent. • (a.) Having the radicle of the embryo lying against the back of one of the cotyledons; incumbent.
No`to·rhi'zal adjective [ Greek ... the back + ... a root.] (Botany) Having the radicle of the embryo lying against the back of one of the cotyledons; incumbent.