Weed or not ?

Large Bindweed

Large Bindweed

 

Large Bindweed growing up a young Silver Wattle

Large Bindweed climbing up a young Silver Wattle

 

Large Bindweed flower showing pointed bract

Large Bindweed flower showing pointed bract


A good first rule to follow in weed management is to be absolutely sure of the plant’s identification before undertaking any control work. So we were pleased when the manager of a large property fronting the King Parrot Creek asked us about the identification of a creeper growing along the creek bank. He was worried that it was climbing up tree-trunks, and wondered if it was a weed that needed control with herbicide.

 

The leaves and flowers looked familiar and appeared to belong to a bindweed (Calystegia sp.), but whether native or not was the question. With the aid of a couple of good reference guides we tentatively identified the plant, by its leaf shape and particularly its pointed flower bracts (see photo below), as the native Large Bindweed (Calystegia sepium). Large Bindweed is a vigorous twining/climbing plant of swamps, stream banks and flood plains. Our identification was confirmed by a professional botanist, who values the plant for its ability to strangle and pull down Phalaris (Phalaris aquatica) stems, while native Common Reed (Phragmites australis) is generally strong enough to cope with it.

Large Bindweed twining up a Phalaris stem

Large Bindweed twining up a Phalaris stem

 

 

 

 

 

 

 

 

 

 

 

Phalaris, introduced as a robust pasture species, has become a significant environmental weed, particularly in wetlands and damper parts of roadsides and bush remnants. Its tall dense biomass represents a fire hazard and suppresses native plant regeneration, so any indigenous plant that manages to control and outcompete it is surely welcome. This can be seen to good effect in the Yea Wetlands, where there is a flourishing population of Large Bindweed in an area once dominated by Phalaris.
 

Purple Loosestrife

Purple Loosestrife

 
Another showy plant in flower on the banks of the King Parrot Creek at present is Purple Loosestrife (Lythrum salicaria), pictured at left. Although sometimes cited as a weed, this plant is in fact native to southeastern Australia. However, it has apparently become an invasive weed of North American wetlands. One man’s meat is another man’s poison!

 

 

 

 

 

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Lilies (and grasses) of the valley

Some of the better-protected roadsides and bush remnants around the Valley of a Thousand Hills are currently displaying a range of indigenous lilies in flower. While these are showy and eye-catching, there is another group of plants also flowering that generally goes unnoticed – our native grasses.

Grass flowers lack petals, but the exposed reproductive parts (anthers and stigmas) can be colourful and attractive in a more subtle way. But you need to keep a close watch as the period of flowering (anthesis), when pollination occurs, is short, perhaps just a few hours.

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Saving Snow Gums

A new generation

A new generation

Back in the 1990s we noticed a group of three unusual-looking low spreading white-trunked trees, high on a steep ridge overlooking our property near Strath Creek. From a distance we assumed they were stunted Candlebarks (Eucalyptus rubida), although it seemed an unlikely spot for them to be growing. On closer inspection they were clearly not Candlebarks, so we took samples of leaves, buds and fruit, and back home we very tentatively identified them as Snow Gums or White Sallee (Eucalyptus pauciflora ssp. pauciflora). This was later confirmed by a DSE botanist, who explained that, as well as in the mountains of eastern Victoria, isolated remnants of these trees can be found right across central and western Victoria to the South Australian border, and in lowland areas such as the Yarra Valley and even the Mornington Peninsula.

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Young and old

Young and old

In February 1998 some members of the Strath Creek Landcare Group visited the site and discovered that not only were the three gnarled old trees being knocked around by cattle, but there were several small progeny of the trees nearby that had large lignotubers (woody swellings at the base of the trunk containing food reserves and dormant buds), indicating that they were being repeatedly browsed by sheep and cattle, not to mention the wild goats that roamed the hills. So the Landcare group decided to protect the area, and in May 1998 an intrepid band of members fenced off about half an acre around the trees on the challenging steep rocky site.

Ancient and on the way out?

Ancient and on the way out?

Now, sixteen years later, the fence is sound, the three old trees are still alive, although one is looking worse for wear, and the good news is that there are at least fifteen healthy young Snow Gum sapling growing in the protected area alongside Silver Wattles (Acacia dealbata) and a Blackwood (Acacia melanoxylon).

Leaning, but with a healthy canopy

Leaning, but with a healthy canopy

 

 

 

 

We have subsequently learnt of at least 2 other Snow Gums growing in the Strath Creek area – one at the western end of the Yea Spur, and the other off Allandale Road. Fortunately both of these sites are now protected under the Strath Creek Biodiversity Project, and hopefully will be able to regenerate naturally.

Some dieback, but surviving

Some dieback, but surviving

 

 

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A local botanist has suggested that some of these trees, with their massive lignotubers, could be very old indeed, perhaps many hundreds of years – but we’re not about to cut one down to count the growth rings !

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