Tuesday, November 24, 2015

Small-leafed Water Vine

Clematicissus opaca
(Cissus opaca)
FAMILY: VITACEAE


I have failed (again) to catch this plant in flower, so am showing you the spent flowers, without their petals and all ready to grow into the little black fruits which will ripen in autumn.
 I suspect that the petal phase of the flowers must be rather short, as this plant had plenty of bud and plenty of spent flowers, but no petals to be seen.

Another clue to the plant's family are the seeds. There are only 2-4 per fruit, and they are so large they almost fill the fruit, but you can see they are unmistakably grape seeds.
 
You can eat the fruits, but as with most local native grape species they are only tolerable when very ripe, and even then not very interesting.

As so often happens with closely related plants, one member of the group is adapted to drier conditions. This member of the grape family is in the Cissus group, and the secret of its drought hardiness is its large tuber. In very dry or frosty conditions it dies back, regrowing from the tuber when warm weather and rains come.

The tubers get very large – as much as 30cm long and 15cm in diameter. A friend who is a clever gardener suggested I plant one in a pot, with the top of the tuber exposed. The result is a rather nice pot plant, which needs a bit of light trellis to support it.


Young tubers are said to be edible, and can apparently be eaten raw or roasted. They have a pungent taste which has given the plant the alternative common name of “pepper vine”.

The plant grows into a light vine. Grown in the ground, it needs only a small trellis or can simply allowed to ramble though a shrub or sprawl over rocks. Even the smallest garden would have room for  few of these plants.

Their leaves take so many forms that they can be difficult to identify in the wild. The leaves have 3–7 stalkless leaflets, arranged like fingers on a hand. The distinguishing characteristic is the middle “finger” which is much longer than the rest. The leaflets can be narrow to medium width, toothed or not, softly hairy or smooth and shiny, and have whitish or reddish backs.


Note the sprig at top right of the photo, showing a tendril coming from the stem opposite a leaf. (Click on the photo for a closer look.) This is another clue that the plant is in the grape family Vitaceae. Unlike some grape species, however, this one has few tendrils and on some plants there may be none to be seen.

In times of desperate drought, when water restrictions make garden watering impossible, it is reassuring to know that plants like this will survive even if their beauty is temporarily lost.

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