Identifying weeds is a crucial part of maintaining the health of riparian zones - so what is involved in working out which plant is Cat's Claw Creeper? In this episode of Save Our Catchment Virtual Excursion, you will learn how to identify the noxious weed, Cat's Claw Creeper, using scientific and botanical classification techniques. (4:53)
WARNING – Aboriginal and Torres Strait Islander viewers are warned that the following video may contain images and voices of deceased persons.
[Screen reads – Focus question: What are the physical characteristics of the Cat’s claw creeper that could help you identify the plant in your local catchment area?]
Narrator
The Cat's Claw is a vine that can reach up to 30 metres in height with the support of a tree. Below the soil surface, it is characterised by an extensive tubular root system. It's also known by its common names, Cat's Claw Climber, Cat's Claw Creeper, Cat's Claw Vine, Cat's Claw Trumpet, Funnel Creeper and Yellow Trumpet Vine. In this Virtual Excursion, we are investigating the Cat's Claw Creeper in the riparian zones of the Upper Clarence River catchment.
[Screen reads – How would you know if you have Cat's Claw Creeper on your property?]
How would you know if you have Cat's Claw Creeper on your property? Generally, the plant grows alongside the creeks and rivers but more specifically, when you look at the Cat's Claw Creeper you will notice the stems are hairless and green in colour, often with reddish-brown or bronze-coloured tips. The stems turn light brown or greyish and become woody as they age. Older stems are here to support such tree trunks via short rootlets, while young stems are here to support via core-like leaf tendrils.
The compound leaves are oppositely arranged and are born on leaf stalks. They consist of a pair of oval leaflets and a third leaflet that has been modified into small, three-clawed tendrils. These tendrils are very important to the success of the creeper as they allow the plant to grip onto trees, fence posts and even cliff faces. These tendrils allow the plant to attach itself to trees as support while it climbs up towards the canopy searching for sunlight.
The showy bright yellow flowers are four to 10 centimetres long and up to 10 centimetres wide. They are best described as tubular and have five petal lobes, each about one to two centimetres long. These flowers usually have several fine, reddish orange lines in their throats. They also have five particularly few sepals, 10 to 18 millimetres long. Flowers are born singularly or in the small clusters originating in the leaf forks.
The fruits are initially glossy green in appearance but turn dark brown as they mature. They are very elongated, flattened strap-like capsules. Each fruit contains numerous papery seeds. These oblong seeds have two see-through wings. They are not easily separated from the rest of the seed. Seeds are usually dispersed in the wind and water. Expert Terry Moody describes here the plant and how it successfully spreads in the riparian zone.
Terry Moody [CEO and weed expert, Upper Clarence combined Landcare] – It has lovely yellow flowers. And the thing that makes it flower is actually sunlight. So you can actually get quite large vines growing up trees and they've never flowered. It's only when they get to the top and they get exposed to light that they will flower. Beautiful yellow flowers, if you see yellow flowers in the treetop in riparian areas in particular, you're pretty certain you're gonna have a Cat's Claw issue.
When it flowers, it then produces seed pods which are like long bean pods and they split open and you end up with very, very fine, flaky, paper-like seeds that blow on the wind. So that's one way that it disperses. So I've seen the sky in this area just literally full of floating seeds.
The other way is that the vine itself underground actually has small tubers. So if you think of a sweet potato, so an average sweet potato might be say, that size. Well Cat's Claw sometimes that size, sometimes, or virtually always, a mixture of big one connected to a little one, connected to another big one, connected to another little one, all the way down the profile through the soil. So you can imagine, flood comes along, takes some creek bank with it, there go some tubers as well. So it spreads by both seeds and tubers. It can spread without going naturally of course is if people pick up and remove soil from somewhere.
[Screen reads: Fact. Cat’s claw creeper established itself as a week in the Clarence River riparian zone in the 1880’s]
So established in the 1880s, it's now all over the place and it is so bad it's now declared weed of national significance.
Narrator
The Cat's Claw Creeper is so successful because it is a resilient plant that has evolved very effective seed dispersal strategies. The plant is opportunistic and will grow where others would not. The deep, complex roots and wide strong vines make it difficult to kill. There is no real natural threat to this plant in Australia. The riparian and climate zones of the mid-north coast provide a perfect habitat for the Cat's Claw Creeper.
List of sources and acknowledgements:
- Video – Drone footage of The Everlasting Swamp. We would like to thank The Everlasting Swamp National Park and Jessica Robertson Photography and Design for contributing their beautiful drone footage
- Narration – Voice over by Robert Llewellyn, New Soul Projects
- Acknowledgment – We wish to thank Father Pop Harry Walker, Annabelle Walker, Roy Bell, Jubullum Local Aboriginal Land Council, Steve Walker, Marty Walker, David Foley, Upper Clarence River Landcare, Terry Moody, Steven Ross, Frederick Ellis
[End of transcript]