Rheum rhaponticum and Rhubarb plant

Rheum rhaponticum noun - Long cultivated hybrid of Rheum palmatum; stems often cooked in pies or as sauce or preserves.

Rhubarb plant and Rheum rhaponticum are semantically related. In some cases you can use "Rhubarb plant" instead a noun phrase "Rheum rhaponticum".

Rhubarb plant noun - Plants having long green or reddish acidic leafstalks growing in basal clumps; stems (and only the stems) are edible when cooked; leaves are poisonous.

Rheum rhaponticum and rhubarb plant are semantically related. Sometimes you can replace phrase "Rheum rhaponticum" with "Rhubarb plant", this phrases are similar.