Rhubarb belongs to genus Rheum, a genus of perennial plants that grows from thick short rhizomes. The genus's in the family Polygonaceae, and includes the vegetable rhubarb (Rheum rhabarbarum or Rheum x hybridum.) The plants have large leaves that're somewhat triangular shaped with long fleshy petioles. The flowers are small, greenish-white to rose-red, and grouped in large compound leafy inflorescences. A number of varieties of rhubarb have been domesticated both as medicinal plants and for hu… (More on Rhubarb)