WATER PLANTS - 20 February 2005

This excursion took place at sites along Ewing Marsh which stretches behind the sand dunes between Lake Tyers and the Snowy River . Our first stop was in the Ewing Marsh State Game Reserve after travelling down Wombat Track. In the vegetation above the freshwater swamp was Blue Box ( Eucalyptus bauerana ) upon which we found a Bag Moth caterpillar and a weevil. Weevils are beetles; they form the largest beetle family in Australia with about 8000 species. They all have their mouthparts at the end of an elongate snout, so they are sometimes known as elephant beetles. Their larvae are legless and usually feed on wood or other plant parts. Beneath the canopy was Hedgehog Grass ( Echinopogon ovatus ) - a small grass with very sharp siliceous edges and a spiky inflorescence. There was also Angled Lobelia ( Lobelia anceps ) where the stems are angled or winged by the leaf bases, and bear small pale blue irregular flowers with five petals. In the marsh was the herb Gipsywort ( Lycopus australis ) which is in the mint family Labiatae. It is more than 1m tall with toothed leaves and white flowers and has a fruit salad aroma. There was also Cumbungi or Bulrush ( Typha domingensis ), a plant up to 2m with broad strap-like leaves and a dense cylindrical spike; Erect Marsh-flower ( Villarsia exaltata ) which has yellow flowers with fringed petals; Scrub Nettle ( Urtica incisa ) which is recognised by almost everyone for the painful stinging hairs on its leaves and stems; the rare Slender Mud-grass ( Pseudoraphis paradoxa ) which was quite profuse here, but is known in Victoria from only a few recent collections from creeks and swamps between Nowa Nowa and the Snowy River, and the shores of Glenmaggie near Heyfield; and Pale Knotweed ( Persicaria lapathifolia ) with drooping pink flower spikes. The generic name for Pale Knotweed is from the Persian 'persica' (peach) because of the similarity of its leaves to peach leaves; the specific name 'lapathi' is Latin for dock and 'folia' is Latin for leaf, so that the leaves also resemble the leaf of dock. Another Persicaria was Smartweed or Spotted Knotweed ( P. praetermissa ) where each leaf has two spots and pink or white flowers. The sedges River Club-rush ( Schoenoplectus validus ) and Club-rush ( Bolboschoenus caldwellii ) plants had spider webs in their inflorescences. The presumed female spiders were yellowish brown with pale stripes, large fawn abdomens and brown spiky legs. The big web seemed to have a female at its centre and small brown male at the edge. Another sedge was Tall Sedge ( Carex appressa ) which is abundant in freshwater swamps. There was also the weed Yellow Marsh-cress ( Rorippa palustris ); and two daisies, Common Cudweed ( Euchiton involucratus ) which is a low perennial with terminal flower clusters; and Grass Daisy ( Brachyscome grammea ). The edge of the marsh was lined with Swamp Paperbark ( Melaleuca ericifolia ) with underneath Sea Celery ( Apium prostratum ), a prostrate herb related to edible Celery whose stems were eaten by the aborigines. One of the Kangaroo Apples, Gunyang ( Solanum vescum ) was in flower. It has pale-mauve to purple flowers with the corolla (petals) only just notched between each petal. There were many small Pennywort ( Hydrocotyle sp.) plants. The name Hydrocotyle comes from the Greek hydro (water) and kotyle (dish or plate) - many of the leaves are depressed in the centre.

We moved on to Lake Beatle which is a land-locked freshwater lake which does not form part of Ewing Marsh. The water level was very low, so that a strip of richly organic black mud surrounded the lake. Vegetation on the mud included a rayless Shrubby Fireweed ( Senecio minimus ). Other plants were Swamp Goodenia ( Goodenia humilis ), a dwarf perennial with a rosette of leaves and 2-lipped yellow flowers; Angled Lobelia; Pennywort; Rush ( Juncus ); a herb Brooklime ( Gratiola pubescens ) with a rosette; Common Cudweed; Red-fruit Saw-sedge ( Gahnia sieberiana ); and Showy Cassinia ( Apalochlamys spectabilis ), an erect herbaceous plant with large soft green leaves, white woolly stems and an inflorescence up to 30cm long. A couple of specimens of the tiny beautiful orchid Austral Ladies Tresses ( Spiranthes sinensis ) were seen. It has many pink and white flowers that spiral around the stem. Several Black-fronted Dotterels ran about the open area close to the water and could be heard peeping; a Welcome Swallow flew overhead and a Sacred Kingfisher perched on a dead stump. Other birds were Great Cormorant and Superb Fairy Wren. Several shells of turtles were found upturned on the mud. Perhaps they had been killed and eaten by Sea Eagles or other predators. A Striped Marsh Frog was captured in the reeds. A Bluebottle Wasp was observed dragging a paralysed cricket many times its size down into its burrow in the mud. The Bluebottle is a stingless wasp where only the females have wings. We found two interesting butterflies. One was the Swordgrass Brown whose caterpillars feed exclusively on Saw-sedge leaves. The other was the blue swallowtail butterfly Common Imperial Blue whose caterpillars feed exclusively on Black Wattle ( Acacia mearnsii ) leaves where they are attended by ants. The ants collect excess honeydew from the caterpillars and in return protect the larvae from predators. These butterflies are found from Victoria to southern Queensland and the pupae are often clustered in community webs where they are still protected by their guardian ants. These butterflies are larger than the Blue Triangle.

Our last visit was back to Ewing Marsh, about 3km west of Corringle which is across the Snowy River from Marlo. From here we climbed across a very bare, steep (one step forwards and two steps back, hands and knees) dune to get to the ocean.