Cassytha pubescens

downy dodder-laurel

 

Cassytha pubescens

R.Br. 1810

pronounced: kas-SITH-uh pew-BESS-kenz

(Lauraceae — the laurel family)

synonym — Cassytha paniculata

R.Br. 1810

pronounced: kas-SITH-uh pan-ick-yew=LAH-tuh

synonym — Cassytha phaeolasia

(F.Muell.) Benth. 1870

pronounced: kas-SITH-uh fee-oh-LAY-zee-uh

common names: downy dodder-laurel, common devil's twine

native 4Cassytha is most probably from the Greek κασσυω (kassyo), to stitch like a shoemaker; pubescens is Latin for ‘reaching puberty’ – becoming hairy. In the synonyms, paniculata is from panicula, a tuft or panicle, and phaeolasia is from the Greek φαιος (phæos), dusky, grey.

Although it is native to Australia, this parasitic twiner is a noxious weed. Its stems are usually 0.5–1.5 mm thick, its young shoots white or red, retrorsely pubescent to woolly; the haustoria are 2–3 mm long.


The inflorescence is a spike, raceme or panicle, the flowers often clustered in more-or-less sessile or stalked heads. The flowers are sessile or almost so, and the petals are pubescent.


The fruit is globose to obovoid, 8–10 mm long, pubescent (sometimes sparsely so), and is coloured green, drying to a grey-black. The stone is a similar shape to the whole fruit, and about 4.5 mm long. This plant is widespread throughout most of Australia and New Zealand, and also in most other tropical and sub-tropical regions of the world.

It is a leafless vine parasitic on a wide range of host plants. The plant photographed is in the small island of neglected council garden in Granite Street, Picnic Bay, outside the site of the old service station. Hopefully it is contained there – I haven’t seen other occurrences nearby – but it is a very hardy and persistent plant, and I am surprised that the ‘Greening Townsville’ department hasn’t tried to eradicate it, to avoid its further spread.

The vine creeps along the ground, and then twines itself into trees and bushes, creating a dense mat that damages or destroys the plant by sheer weight, or by sucking the life out of it. It will scramble over undergrowth and trees to a height of about 3 m.

This is a food plant for a number of caterpillars, including those of:
• Blotched Blue Candalides acasta,
• Twin Dusky Blue Candalides geminus and
• Small Dusky Blue Candalides erinus,
• Whistling Moth Hecatesia fenestrata and
• Bordered Emerald Eucyclodes buprestaria.

Alarmingly, to my mind, experiments are being undertaken, particularly in the Mount Lofty region of South Australia, to use the plant as a biological control of imported species of gorse and broom. It is perfectly true that it will often kill these species, but it also spreads to nearby native species, where it seems to flourish equally, although it does not have so severe an effect.

The ‘dodder’ in the common name refers to the uncanny resemblance of this plant to the dodder (genus Cuscuta). The two are, however, not at all related. Our plant is in the Lauraceae, related to the Sassafras, avocado and cinnamon, whereas dodder is in the Convolvulaceae, and is related to the morning glory vines.

 

Photographs taken in Picnic Bay 2009
Page last updated 2nd November 2018