Eryngium alpinum, the alpine sea holly, alpine eryngo or queen of the Alps, is a herbaceous perennial plant in the family Apiaceae.
Eryngium alpinum is a hemicryptophyte, its overwintering buds are situated just below the soil surface and the floral axis more or less erect with a few leaves.[1] The roots are deep and robust.
The stems are solitary and erect, usually with three branches on the apex and with longitudinal purple stripes. This plant generally reaches about 30- in height,[1] with a maximum of . The basal leaves are oval or heart-shaped, 10- wide and 13- long,[1] with toothed hedges and a long petiole. The cauline leaves are sessile and progressively more divided.[1]
The inflorescences are dense umbels at the top of the main branches. They are bright green at the bases and the stiff, bristly bracts are blue. They are about 4 cm long and 2 cm diameter and the bracts are up to long.[1] The flowers inside are about 2 mm long. The peripheral flowers are sterile and the internal flowers are hermaphroditic. Both types are actinomorphic and pentamerous, with five petals. Flowering occurs in July through September.[1] The flowers are -insect-pollinated. The fruit is a spiny achene about half a centimeter wide.[1]
This plant is native to Austria, Liechtenstein, Croatia, France, Switzerland, Italy, and Slovenia.[2] It grows in subalpine scrub, rocky areas and wet pastures, preferably in limestone, at an altitude of 1500- above sea level.[1]
Eryngium alpinum is cultivated as an ornamental plant for its blue and purple flowerheads. It requires dry, well-drained soil and full sun.[3]
Wild populations of the species are in decline due to overcollection for ornamental use and habitat degradation from recreational activity and grazing. Numerous local extinctions of subpopulations have occurred.[4]