Author: Cheryl Haxen

'Black-eye Susan'/Clockvine

Family Acanthaceae

A perennial creeper native to Tropical and Southern Africa.

(The common name Black-eye Susan is sometimes used for Rudbeckia daisies which are unrelated)

I can recall this plant being introduced, with some excitement, to a garden in Zimbabwe. It was likely also introduced in Australia as an ornamental.

The photographs in this post are from my own garden, where plants arrived unbidden. The photos show how a few months of inattention result in the ability of the creeper to smother everything beneath a blanket of leaves, bright flowers, and twining stems.

The climbing stems are easy to remove, and roots easily pulled. However, wherever stems touch the ground, they set root from every node, so continual removal of fresh growth is necessary.

The smothering of garden plants is however the least of the problem, as this feature applies to native vegetation. Although T.alata is not declared, the  Brisbane City Council weed identification tool describes it as:

'A weed of waterways (i.e. riparian vegetation), urban bushland, forest margins, plantation crops, roadsides, disturbed sites and waste areas in tropical, sub-tropical and warmer temperate regions.

Black-eyed Susan (Thunbergia alata) is regarded as an environmental weed in New South Wales and Queensland. It is also a potential environmental weed or "sleeper weed" in Western Australia and the Northern Territory'

The flowers attract insects to the good nectar source, and I was loathe to remove the plants during the recent splendid emergence is butterflies.

It is said threat seeds are spread by birds, but I can not find any good evidence for this, either online, or by personal observation.