Description
Olearia adenocarpa is critically endangered. It is endemic to the Canterbury Plains. Known only from the vicinity of Christchurch. Severely threatened by browsing animals and habitat loss. The few wild specimens are caged along the Rakaia and Waimakariri Rivers as conservation efforts persist. However, caged plants are vulnerable to overtopping by pasture grasses. Olearia adenocarpa generally grow in degraded to unimproved dry grassland along the dry stony terraces and channels that border a braided riverbed. Located on dried braided river beds, environmental conditions for this plant are extreme, ranging from drought-like conditions to flooding covering the plant. It however has adapted to these conditions as can be seen in the low to the ground growth of this plant. Rarely seen in abundance and generally scattered individuals.
Wai-Ora Nursery is involved with conservation efforts, growing hardwood cuttings for conservationists from the few individual plants that remain. These few cutting grown plants will then be transplanted back to near their parent plant in hopes that ungrazed plants will then produce seed to aid in natural repopulation. Researchers believe that only ungrazed Olearia adenocarpa have the ability to reproduce. Easily grown from cuttings and fresh seed.
Olearia adenocarpa has small egg-shaped leaves. The upper side ranges in tone from light green to a dark browny-green or grey-green with a hairy silvery-white underside. Clusters of flowers begin to bloom in January. These are usually white in colour with a yellow-green centre. New branches form at or below ground level on a regular basis to compensate for the short-lived main branches, which generally only live up to 12 years. Branches run along the ground and surface with their ends curved upwards with a few older upright branches that are essentially vertical.
As part of the dry woodland community, it plays an important role in conditioning the soil. The soil conditioning creates a more hospitable environment for less robust species and broadleaf/podocarp forest succession. Other plants in this community include but are not limited to Discaria toumatou, Poa cita, Ozothamnus leptophyllus, Corokia cotoneaster, Melicytus alpinus and Cordyline australis.
For more information on plant communities, we recommend DOC’s publication Native Plant Communities of the Canterbury Plains.
