Rubber vine (Cryptostegia grandiflora
) is a highly invasive perennial woody shrub or vine. It is native to Madagascar, but widely distributed throughout tropical and subtropical regions worldwide. There have been many documented cases of toxicity in horses across Australia, as a result of ingestion of rubber vine.
What does rubber vine look like?
- Height: C. grandiflora can grow unsupported 1-2 m high, or it can scramble up to 30m high in trees.
- Stems: It has grey-brown stems that are covered in raised spots.
- Leaves: It's leaves are thick , leathery, glossy dark green on the top surface and pale and dull on the bottom.
- Flowers: It's flowers bloom primarily in the summer, producing white, purple or pink colored tube-shaped flowers.
- Fruit/Seeds: Green or brown pairs of pod-like fruits containing flat brown seeds are formed between the summer and late autumn months.
stems, leaves and unripe seed pods exude a white, milky sap when broken or cut.
What toxins does rubber vine contain?
All parts of rubber vine contain cardiac glycosides, in both dry or fresh form. Cardiac glycosides inhibit the cellular Na+/K+-ATPase which enhances cardiac inotropy (contractility) and slows the heart rate. Horses are particularly susceptible to poisoning by this plant.
- Loss Of Appetite
- Profuse Sweating
- Muscle Twitching
- Progressive Muscle Weakness
- Severe Cardiac Arrhythmias
- Labored Breathing
- Cyanosis Before Collapse And Death
MANUAL CONTROL: Rubber vine can be effectively controlled by burning. Two successive annual burns are recommended.
MECHANICAL CONTROL: For scattered or medium-density infestations, slashing the vines close to ground level is found to be effective. For dense infestations, during the winter, stick-raking or blade-ploughing reduces the bulk of the infestation. Pasture should be sown and windrows burned to kill residual seed. Follow-up treatment is essential.
CHEMICAL CONTROL: Rubber vine can be effectively controlled with herbicides. Aerial application, foliar spray, basal bark spray, cut stump treatment, and soil applications.