(1) Irises grow from thick, underground stems, called rhizomes , that store food produced by the leaves.(2) In addition, shrub roots and rhizomes grow into above-ground gaps, making below-ground gaps smaller than above-ground gaps.(3) Despite their differing underground structures, corms, tuberous roots, and rhizomes are all referred to as bulbs.(4) The plant is tough to stamp out because it develops a system of roots and rhizomes , horizontal underground stems that descend as far as six feet into the sand.(5) Mucilages found in rhizomes , roots and seed endosperms may act primarily as energy reserves whereas foliar mucilages appear not to serve as storage carbohydrates.