Thursday, May 31, 2012

Small-leaved Pennywort

Hydrocotyle peduncularis
At the other end of the size scale from last week’s plant is this dainty little pennywort. Its 1cm leaves, almost circular, have five scalloped lobes.

It’s a perennial plant which makes a pretty carpet of soft, fresh green at the water’s edge (both in and out of the water), and mixes happily with other small plants. As with all the Hydrocotyle species, the flowers are inconspicuous.

 Here it is with Pratia pedunculata (oval leaves and small, pale blue flowers) and Utricularia gibba. The latter is the plant with yellow flowers and green thread-like stems, an insect-eating plant which keeps the whole assemblage mosquito-free and allows me to grow water-loving plants without creating a potential disease hazard.

I planted none of them. A shallow muddy area, created in the corner of the birdbath to grow rushes, proved to be a suitable place for the others to appear. I imagine the seeds were brought in from other watery places by the birds.
(See Nov 2008 for more on Utricularia gibba)
Plant lovers can be odd people. In damper parts of Australia than ours, this pretty little native spreads into lawns, something which offends people who like their lawns to be monocultures. Many of the internet references to it, therefore, describe it as a “weed”.
Meanwhile an American plant called water pennywort Hydrocotyle ranunculoides was so valued as an “ornamental” that people have thought it worthwhile to introduce it into Australia, where it has gone on to become a watercourse-choking weed that now costs many dollars to eradicate.
You would really wonder why our own native Hydrocotyle species, attractive plants with no potential to cause environmental damage, are so rarely grown.

Thursday, May 24, 2012

Large Pennywort

Hydrocotyle pedicellosa

 This common rainforest plant is one of our best groundcovers for damp, shady ground. Native only to Queensland and northern New South Wales, it is one of our most instantly recognisable rainforest plants
With a leaf diameter up to 10cm, it is the largest of our pennyworts.

Like most of the plants in this family, its flowers are not its best feature! At only 1mm, they are likely to be overlooked completely, though you do notice the flower-heads at the end of summer.

However, it is for the carpet of lush green leaves that we would grow this plant. It does best where the ground never dries out - but once established will survive for short periods in dry soil.

Friday, May 18, 2012

Pearl Vine

Sarcopetalum harveyanum
Some of the Friends of the Escarpment Parks found these startling fruits, while they were working in Redwood Park down near the bottom of the Range. They were all olive-brown when first found first, but are now ripening to this shade of rich, ruby red.

The plant is a female pearl vine, climber which typically produces its pretty pinkish-red flowers down low on its slender woody stems - probably because it is pollinated by some kind of insect that walks to work.
As so often happens with rainforest vines, most of the leaves of this one were too high to be seen easily. We managed to find just one to photograph.

Pearl vines have potential for use in gardens. Young ones could be used for indoor plants.

Friday, May 11, 2012

Water Poppy

Ottelia ovalifolia 
As you can see, these plants really have nothing to do with poppies, which have four petals. These three-petalled flowers are more closely (though not very closely) related to lilies.

 It’s rather late in the season for water poppies, but I found these a few weeks ago, in a sheltered, sunny waterhole in Reinke Scrub near Proston.

Also not related to “ordinary” water lilies (Nymphaea species), these are smaller (6cm) flowers which last only a day, but are plentifully produced throughout the warm season.

 The plants need to anchor themselves in the mud at the bottom of the pond (or could to be established in a pot). They prefer shallow water, but can cope with depths of up to 60cm. A sunny situation is essential for flowering.
They grow easily from seed, but the seedlings will surprise you. Juvenile, underwater leaves are strap-shaped, so you might think that you are looking at a different plant!
Water popiesand revert to the underwater straps of their childhood.
In colder situations they are likely to behave as annuals. They are also less ornamental. All of them have a tendency to produce some underwater buds which never open, but have the curious ability (known as cleistogamy) to produce seed without being needing to be fertilised by insects. In colder climates, the plants produce more of these cleistogamous flowers, and fewer, if any, chasmogamous ones. (This lovely word just means the ordinary kind of flower with petals!) You might be excused for thinking that they are not flowering at all.
They like their water to be nitrogen-rich, and are a bit touchy about pH, preferring it to be under 6.2, (so might not thrive on our black soil which is more alkaline).

Thursday, May 3, 2012

Snake Vine

Hibbertia scandens

This plant is looking brilliant, on the fence at Peacehaven Botanic Park just now.

Snake vine is a plant which grows naturally along Australia’s Eastern coastal strip, extending to the eastern edge of our district where it grows in rainforests on the great Dividing Range, (as at Goomburra). It is likely to have once been native to the Toowoomba area, though we will never know for certain because our local rainforests were thoroughly cleared, early in the period of white settlement.

The inland form of the plant is less hairy than the coastal form. Its dark, shiny green leaves provide a good background for the bright yellow flowers.

We can expect this month's flowers to produce red, bird-attracting seeds around March.

Snake vine can be a bulky plant, with many scrambling, 3m stems which can’t decide whether to twine clockwise or the other way about. It is fast-growing, and makes a quick cover for a trellis or fence. It can also be allowed to ramble among trees and shrubs, though there is a risk that it might smother the smaller plants.
In full sun it is naturally dense, but if grown in the shade it might need pruning to keep it within bounds and improve its density and screening capacity.
It is fairly drought hardy, but survives only light frost.

Just a reminder: you can find out more about Peacehaven at