rose of Sharon, (Hibiscus syriacus, or Althaea syriaca), shrub or small tree, in the hibiscus, or mallow, family (Malvaceae), native to eastern Asia but widely planted as an ornamental for its showy flowers. It can attain a height of 3 metres (10 feet) and generally assumes a low-branching pyramidal growth habit. The mallowlike flowers range in the different varieties from white and pinkish lavender to purple, generally with a crimson base; certain varieties have double flowers. Hypericum calycinum, of the family Clusiaceae, is also called rose of Sharon.