This Eryngium or 'Sea Holly' is actually a hardy perennial, but looks more like some tropical plant like an agave or pineapple, it has statuesque, rich green very sharply toothed leaves (often producing a yelp, or worse at the nursery when someone has forgotten to wear gloves) and preferring a sunny spot in a well drained, but moist soil, it looks really great in a large container too.
It has thistle like green/white flowers on rising stout upright stems from June onwards,
