Term 3 – Plant Study – Waiu-atua (Euphorbia glauca)
Waiu-atua (Euphorbia glauca) is a very attractive coastal plant which grows to about 40-60cm. height with greyish-green or blue leaves and a distinctive milky sap. There are many introduced species of the Euphorbia plant group used as garden plants in New Zealand but waiu-atua is our only indigenous and endemic species. While once regarded as common on mainly coastal sites it has suffered from a declining and deteriorating habitat and is now found only in small widely scattered populations on sand, gravel and rocky areas. Common threats include browsing and trampling by animals such as cattle, sheep, goats and possums as well as weed invasion and erosion. It has a conservation status of ‘At Risk- Declining’. We have good examples of waiu-atua in our school’s ‘beach garden’ and have been propagating and planting out this species for many years.