Sea Holly (Cuileann trá) In the 16th century, Eryngium maritimum was considered a strong aphrodisiac. We are sworn to secrecy, but in any case, Sea Holly is a widespread native, easily recognised due to its waxy, spiky appearance. Sitting happily in clumps on the sand of many an Irish beach or dune, it has leathery, silver-blue, holly-like leaves with white veins. The whole plant is blue, as are the flowers: tiny and arranged in round umbels, out from June to September. Loved by bees. Good unusual looking plant for coastal themes or exposed areas. Site: Seaside hardySoil: Well-drained sand or shinglePosition: Full sunSeason of Interest: Evergreen, blue flowers Jun-Sept, waxy leavesHardiness: HardyHeight: 2ft (0.6m) Spread: 1.5ft (0.4m)