Family: Araliaceae

Status:

Description:
English ivy climbs up tree trunks, clinging by small clusters of aerial roots to the bark, unlike most climbers which have twining stems or tendrils. It has 3 lobed leaves, which are thin-textured and only slightly glossy, often with a slight whitish marbling. Leaves on flowering stems are larger, and are not lobed. It has inconspicuous greenish flowers in clusters, followed by black berries. There are variegated forms with a lot of white marbling on the leaves, which are also potentially invasive.

Preferred habitat and impacts:
Found mostly around towns or old farms, but birds can spread the seeds into the bush some distance from habitation. Very shade tolerant, although only branches exposed to sunlight will produce fruit.
Smothers trees by climbing high into the canopy. Can smother tree ferns and shrubs similarly. Also trails over the ground, forming a dense mat which suppresses all native ground vegetation and prevents tree regeneration.
Both berries and leaves are poisonous.

Dispersal:
It can reproduce vegetatively, from stem segments dumped or transported by floods. Stems trailing over the ground will root at the nodes. Seed is spread by birds.

Look-alikes:
The native common silkpod (Parsonsia straminea) climbs tree trunks with aerial roots like English ivy when young, but its leaves are not lobed. Mature plants lose this feature and climb by twining.
The weed cape ivy (Delairea odorata) has slightly similar lobed leaves but they are brighter green and the plant climbs by twining.

Control:
Hand-pull small plants and remove. Plants left lying on the ground will re-grow. For badly infested trees, cut away at least the bottom metre of ivy stems around the trunk and apply scrape and paint treatment to both ends of the cut stems. Stems growing across the ground can be sprayed with herbicide, adding a penetrant to improve take-up of the chemical through the waxy coating on the leaf. Follow-up will be needed.
Do not try to pull ivy down. Treat it and leave it to die in place. If the infestation is extensive, concentrate on controlling the climbing stems before the ground-covering ones, since it is the climbing stems which will produce fruit.