Eryngium amethystinum, the amethyst eryngo, Italian eryngo or amethyst sea holly, is a clump-forming, perennial, tap-rooted herb. Its stem is long and is light blue to purple in colour. It has a basal circle of obovate, pinnate, spiny, leathery, mid-green leaves. It flowers in mid to late summer with cylindrical umbels, 2–3 cm long atop silvery blue bracts and branching stems. The plant is native to the eastern Mediterranean and prefers dry places and soils that are rich in calcium.The Royal Horticultural Society Encyclopedia of Garden Plants, Ed. Christopher Brickell. Dorling Kindersley Ltd. London 1996. p414
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