WAIKAWAU. SOME DUNE PLANTS.

Wandering along the drift line can be very rewarding. You can never be sure what treasure might have been cast up by the sea! It  also happens to be one of the most formidable locations for living things on the planet. It is an interface between two major environments. Mostly it is land, but, sometimes, it becomes the sea. Only a few organisms manage to live in such changeable conditions.

Above the high tide mark conditions are only a little less harsh. The first plant you encounter, at the foot of the dunes, is the sea stock. It throngs with bees when it is in flower. Later it's seeds become the food for the introduced greenfinch.

Pingao

Then the native sand binders, Spinifex and Pingao appear holding and building the protective fore dunes. The seed head of Spinifex cartwheeling along the beach in summer is a familiar sight.

Spinifex

The dunes favours those plants that have a particular edge. Some are very good at conserving water.

Sea Convolvulus

Some, like the sea convulvulus manage to get through their life cycle and produce seed before the harsh summer arrives.

Bush lupin

The bush lupin has two advantages at least. It has deep roots so water is less of a problem. In a low nitrogen environment it also gets extra nitrogen from the air.

The catchfly, with its sticky leaves and stems also supplements its mineral requirements from the insects which become glued to it.

Getting a free ride is the parasitic broomrape. It has no chlorophyll but gets it's food from the roots of other plants.

Further back from the sea the plant cover becomes more complete and the sand binders more infrequent. Eventually larger plants, more bush like,start to appear and the sand binders are nowhere to be found.