Sea Holly - Eryngium planum

Common Name :	Sea Holly, Blue eryngo.
Binomial Name :	Eryngium planum
Family :	Apiaceae
Photo Taken :	Ireland

Botanical Identity

Eryngium planum, commonly known as Flat Sea Holly or simply Blue Eryngo, is a striking herbaceous perennial in the Apiaceae family, which also includes carrots and parsley. Native to central and southeastern Europe and parts of western Asia, this plant is now widely cultivated in temperate gardens around the world. The genus Eryngium includes several species with thistle-like appearances, and planum refers to the flatness of the flower heads in this particular species.

Plant Description

Blue Eryngo is a clump-forming perennial herb that typically grows 40 to 80 cm tall. It has deeply lobed, spiny-edged basal leaves and upright, branching stems that give rise to its sculptural inflorescences. The foliage has a bluish-green, slightly waxy appearance. Preferring full sun and well-drained soil, the plant is drought-tolerant once established and thrives in poor, sandy, or rocky soils, making it an excellent choice for xeriscapes or low-maintenance borders.

Flowers and Seed Characteristics

The flowers of Eryngium planum are its most distinctive feature—steel blue to violet, cone-shaped central clusters surrounded by narrow, spiny bracts. These flowers appear in mid to late summer and persist for many weeks, both fresh and dried. The blooms attract bees, butterflies, and other beneficial pollinators. After flowering, it produces small, dry fruits that contain seeds. These seeds can be collected and sown to propagate the plant, although it may also self-seed modestly in suitable environments.

Uses and Garden Value

Though not widely used in cuisine or medicine today, Eryngium planum has some traditional medicinal history as a diuretic and stimulant. Its primary value now lies in ornamental horticulture, where it adds architectural structure, texture, and color to perennial beds, dry gardens, and floral arrangements. The long-lasting flowers also make excellent cut or dried flowers.


Photos of this Sea Holly (Eryngium planum) were taken from the following locations:
1)June 2020: Botanic garden, Dublin.


Written by Lonely Traveler,
For blog icflora.blogspot.com