Eryngium vesiculosum (Hugh Wilson) or E. undulatum* (only native species listed on NZPCN)

A sea holly that transforms from summer to winter. A native too. Great for well drained places. As tough as! 

I think I have E. undulatum. NZ native, and also from E. & S. Australia. A curiosity. In winter it has little sword like leaves without spines, yet in summer it transforms into a lobed, spined, prickly patch, 5cm tall. Spreads by rhizomes. Short flower stalks, 2-3cm, tiny white and crowded at the tip with radiating eryngio like bracts. Flowets in January to February. Mostly coastal. Growing on sandy beaches, coastal gravels, lower drainage areas of rivers, and exposed headlands. Occasionally inland in similar habitats. At risk, also occurs in Australia. 

I have had this for years. From Hokonui Alpines originally. I have only just discovered what it could be as I was reading Hugh Wilson's book "Plant life on Banks Peninsula" 

• NZPCN (a great website for natives) says that E. vesiculosum is an Australian endemic, and is superficially similar, but more upright and blue rather than glaucous (waxy) or grey-green, only they don't mention E. vesiculosum at all. Kew says E. undulatum is the  New Zealand species. Hugh Wilson lists E. vesiculosum occurring on Banks Peninsula where it is rare and local, but also occurs throughout New Zealand on coastal and stony ground. But also in Tasmania and Australia. I think my plant is just like Hugh's great descriptive drawing. However I have never noticed a blue shade o the flowers as some iNaturalist photographers have sent in.