Eryngium
Eryngium, commonly known as blue thistle or sea holly is a striking addition to landscaping with characteristic clusters of spiny flowers. Eryngiums are delightfully trouble-free plants with low susceptibility to pests or diseases. They can tolerate poor soil and are long-lived perennials once established. Their spikes can be quite sharp so it’s a good idea to plant eryngiums away from the edge of a border or path.