- rheum - a watery discharge from the mucous membranes (especially from the eyes or nose)
--1 is a kind of discharge, emission
- Rheum, genus Rheum - rhubarb
--2 is a kind of dicot genus, magnoliopsid genus
--2 is a member of Polygonaceae, family Polygonaceae, buckwheat family
--2 has members:rhubarb, rhubarb plant; Himalayan rhubarb, Indian rhubarb, red-veined pie plant, Rheum australe, Rheum emodi - Rheum, genus Rheum - rhubarb