A hair (often branched) serving as a root;
Thread-like rootlets in pteridophytes;
Small rootlike organs (e.g. coming from the base of the inflorescence in Utricularia).
A rootlike structure attached to the stem base, usually white or brightly colored, soft but tough.
Colonial shape description implying branched, root-like growth (from the Greek rhiza—root, eidos—form).