| Scientific Name: | Eryngium planum |
| Common Name: | blue sea holly, flat sea holly |
| Family Name: | Apiaceae |
| Origin: | Europe |
| Hardiness Zone: | Zone 4: (-34 to -29 °C) |
| Plant Type: | Broadleaf evergreen |
| Mature Size: | 0.7 - 1.3m x 0.3 - 0.6m (height x width) |
| Habit: | Upright |
| Form: | Oval - vertical |
| Texture: | Coarse |
| Landscape Uses: | Attract beneficial insects, Attract butterflies, Cut flower or foliage, Dried flower or fruit, Fall interest, Perennial border, Small garden/space, Summer interest |
| Exposure: | Full sun |
| Soil or Media: | Well-drained |
| Leaves: | Simple, Basal, Leathery, Glabrous, Oblong, Ovate, Dentate, Palmately lobed, Spinose |
| Flowers: | Umbel, Blue, Aug-Sep-Oct |
| Fruit: | Achene, Schizocarp, Brown |
| Key ID Features: | |
| Basal, clumping, taproot; leaves dark green, oblong-ovate, leathery, dentate; flowers blue/blue-green bracts, Aug-Oct, tight clustered spikes, umbels (three or more may arise from common node). | |