Helichrysum dimorphum a riparian shrub that has two forms, a scrambling shrub or a liane with stems up to 8m long. The stems are cord-like, flexible, unbranched but have many slender branches at their ends. From September to February it produces small, insignificant sweet-scented flowers. The shrub can resemble a mass of dead stalks.

It is only found in the South Island and its distribution is the Poulter river, the lower Esk river and Waimakariri river in Canterbury. It is usually found on river terraces and alongside river gorges.