Friday, March 11, 2011

Slender Water Vine

Cayratia clematidea
Family: VITACEAE
Some people dislike this little climber, considering it “weedy”.
I’m fond of it, myself.
Slender water vines are chaotic plants with a tendency to spread at will through the garden. They grow very fast, in spring, creating the impression that they will smother everything in sight - but they never fulfil the promise. The growth slows right down as soon as they begin flowering in summer - which happens when the stems are 2-3 metres long. The plants trail through the foliage of other plants, ornamenting them with these pretty leaves. The flowers are tiny and white, but add to the lacy appearance of this delicate-looking plant. They are followed by bird-attracting black fruits.
In autumn the above-ground parts of the vine die, and are easily pulled off their supporting plants by hand. Under the ground, they survive as tennis-ball sized tubers, to regrow in spring.
The brown tubers are edible, as are the tiny fruits, though neither has much flavour. The tubers were traditionally prepared by beating and roasting.
A very good reason for growing these plants is that they are the favourite host plant of the Joseph’s coat moth. This stunningly beautiful day-flying insect is often mistaken for a butterfly, as it is brightly coloured - black with red, yellow, and light blue markings, and the plant would be an appropriate inclusion in a garden designed to attract butterflies.
This female is probably laying eggs on this plant, which , as you can see from the poor state of its health, must have been treated with glyphosate, so if she did indeed leave eggs there they are doomed.

8 comments:

Anonymous said...

Cannot agree with some of your comments about this climber. It has smothered and killed at least two native trees in my garden at Highfields. I regard it as a pest.

Patricia Gardner said...

Thank you for your comment. It is interesting to hear another point of view. I have had this vine in my Highfields garden for thirty years, and my experience has always been that it doesn't live up to its apparent threat.
I wonder why the difference? Were your smothered plants rather young, perhaps? Or could there have been another cause of death, for the native trees? I wonder what species the killed plants were?
Trish

Ben Stuart-Carberry said...

I think anonymous may have mistaken this vine for the more aggressive Cardiospermum grandiflorum?

Patricia Gardner said...

Probably not, Ben.
The Cardiospermum doesn't like the climate up here at the top of the Great Dividing Range, and doesn't grow here. (We may suffer more from dry and frost, but it does at least save us from some of the feral horrors that you get closer to the coast.)
Like me, you may have more experience of the slender water vine than our anonymous commentor, and know that it doesn't live up to its initial apparent promise of smothering. However the story of this "dreadful smothering vine" is often repeated, usually by people with small gardens who weed meticulously, and get alarmed if anything grows rather quickly to more than a few feet high.
Trish

Helen Schwencke said...

Hi Trish,
Unfortunately Cayratia clematidea does have that reputation, and I've yet to find somewhere where it took over for any length of time. In my inner Brisbane garden it's constantly dying back as the weather cools. If it starts getting away (which I take delight in) it's usually severely pruned by one of other of the Hawk moth larvae that also us it.
The plant is a great habitat plant in my books. It supports the Joseph's Coat Moth as you mentioned and another black and white day-flyer (Cruria donowani), a leaf-eating beetle with larvae that also eat the plant (Oides dorsosignata), several hawk moth larvae that I've yet to breed through, and another little black-blue flea beetle (of which I've only seen the adults use it).
sometimes plants die, and because we see something like C. clematidea climbing on it, we put 2 and 2 together, with our cause and effect thinking (and taught) brains, and attribute the cause inappropriately.
Just because 2 things are correlated doesn't mean they are cause and effect. There's a great statistic out there somewhere which shows a 100% correlation between dying and having eaten carrots in London in the 1830s!
Cheers.

Patricia Gardner said...

Great to hear from you, Helen.
Yes, I was aware of the Cruria and the hawk moth. (They eat a lot, don't they?)
Like me, you are one of those people who love their plants for what they contribute to Life, not just for their looks. Our Cayratia clematidea has been more prosperous than ever before in this last bit of rain, and the Joseph's coats are all over the place.
Trish

Geoff said...

Hi i have noticed this species begin growth in my garden last season. It's great to see this native be drop of by birds in my garden as i did not plant it. I noticed bees love the nectar to. it is very easy to control by cutting back late autumn. I hope to get the Joseph moth soon. Location is western Sydney Macarthur area.

Patricia Gardner said...

Hi Geoff.
Nice to hear from you.
Yes, you are right about the bees. Every new native plant in a garden attracts more than one native animal.
We can hope that there is enough of the plant about for the Joseph's Coat moths to reach your place next season, if not this.
Good luck!
Trish