- rhubarb, rhubarb plant - plants having long green or reddish acidic leafstalks growing in basal clumps; stems (and only the stems) are edible when cooked; leaves are poisonous
--1 is a kind of herb, herbaceous plant
--1 is a member of Rheum, genus Rheum
--1 has particulars:Himalayan rhubarb, Indian rhubarb, red-veined pie plant, Rheum australe, Rheum emodi; pie plant, garden rhubarb, Rheum cultorum, Rheum rhabarbarum, Rheum rhaponticum; Chinese rhubarb, Rheum palmatum