Eryngium planum is a herbaceous perennial that is hardy in the US in zones 5-9. It grows to a height of about 3-4 feet tall and spreads about 16-24 inches wide. Eryngium is native to the Alps, Jura and the Balkan mountains. It can be propagated by division, seed and root cuttings. Propagating it by division may be difficult because of the tap root.