Senecio’s are a group of plants that belong to the Daisy (Asteraceae) family. Locally one member of the family Senecio Jacobaea (Ragwort) is well known as a serious pest to landholders and its impact was one of the contributing reasons that many farms in the Strzelecki Ranges were abandoned. There are however a good number of Senecio’s that are native plants and are an important part of the local environment, particularly as colonisers of disturbed sites, and thus providing ground cover to reduce erosion and keep out introduced weeds.
Rough Fireweed (Senecio hispidulus) grows up to 1 metre tall and has green shiny leaves that have toothed lobes. They are covered in tiny hairs that make them feel a bit like sandpaper to touch. At the base of the leaves where they attach to the stem there are a pair of lobes with teeth (auricles). The underside of the leaves are covered in longer white hairs. Like all of the four species described in this post the flower heads are surrounded by green bracts, without any of the yellow ray florets that look like petals.
Hairy underside of a leaf.
The common name relates to the rough textured lobed leaves.
Flowerhead surrounded by green bracts.
Base of the leaves, where they attach to the stem with a toothed lobe (auricle) on either side.
Fluffy seedheads, ready to disperse in the wind.
Annual Fireweed (Senecio glomeratus) Annual Fireweed has some features in common with Rough Fireweed, it also has toothed lobes at the base of the leaves and the flowerbuds look similar. It is without the roughly textured leaves, it is usually covered in soft cobwebby type hairs.
Clusters of flower heads.
Underside of the leaves have a fine cottony texture.
Also has a pair of toothed lobes (auricles) where the leaves attach to the stem.
Slender Fireweed (Senecio tenuiflorus) as its common name suggests, Slender Fireweed is a more delicate looking plant. Its lower leaves are crowded with toothed margins, while the leaves further up the plant become narrower and more slender. The upper-side of the leaves are slightly cobwebby, while the back of the leaves are quite hairy, at the base of the plant they are usually purple.
Senecio tenuiflorus – Slender Fireweed
Leaves towards the base of the plant.
Underside of the basal leaves, hairy and purple.
Fluffy seed-heads ready to disperse.
Flower heads are narrow and usually wider at the base.
Where the leave connects to the stem, does not have the toothed lobes like the previous 2 species.
Cotton Fireweed (Senecio quadridentatus) – Cotton Fireweed often grows in the same locations as Slender Fireweed and is also quite slender. It is a widespread species and will come up in disturbed areas where little other native vegetation exists, it can withstand dry conditions. It is covered with dense cottony hairs, which can help with its identification, they give the plant its somewhat grey appearance.
Whole plant with greyish leaves.
Long slender leaves.
Narrow clusters of flowerheads, also covered in grey cobwebby hairs.
If you are keen to get a better idea of what species are native to the area, one great resource that is now available is the Atlas of Living Australia. You can search any area and it will come up with a whole heap of information about what has been found. It is focused on all biodiversity so it covers a whole range of flora and fauna including fungi and fish and it doesn’t just come up with lists, it also includes links to photo galleries and other information about each species. If you are really keen the site also gives you the opportunity to upload your own species records. You can find the atlas via the following link http://www.ala.org.au
A weed workshop was recently held at the Callignee Hall where participants were treated to a BBQ meal followed by presentations from Latrobe Landcare Network Co-ordinator Peter Newgreen and Bob Wilson from the Department of Primary Industries.
Key messages on the night included the following tips
Weeds have a number of adverse affects on a range of things including, productivity, stock health, impact on native flora and fauna.
It is vitally important to be able to identify the weed you are a dealing with and know about its life cycle.
Annual species will only last one season, new plants will only grow by seed. They key to their control is to stop the plants producing and releasing seed.
When Perennial plants die off on top, they may still have a healthy root system that is likely to re-sprout. To control them you need to kill the whole plant.
Some species can reproduce vegetatively (e.g by fragments of stem, root or leaf) ploughing in or slashing these species can drastically increase their spread.
Learing some basic information about plant classification can make it easier to identify weeds. Certain features of a plant can you quickly narrow down the possibilities of what the exact species of weed could be.
The best way to control weeds is to stop them becoming established in the first place. Key sites to check for new infestations are along watercourses and drainage lines, as well as sites where introduced fodder has been spread, along roadways and traffic areas and around stock camps.
Integrated Pest Management – (Where a variety of actions are taken to control a weed. e.g use a variety of types of suitable herbicides, good pasture management etc are undertaken) is vital otherwise weeds are likely to become resistant to your control method.
People tend to notice weeds that are Yellow (e.g. Ragwort) or Purple (e.g. Pattersons Curse) but they don’t pay enough attention to grasses. People need to be vigilant for serious weeds such as Serrated Tussock and African Love Grass.
Identification of weeds can be difficult, especially as some features used for identification of the plants are not always present e.g flowers/seed pods. If in doubt samples can be taken in to your local DPI office.
The worst established weeds in the district are Blackberry, Ragwort and there are some patches of Patterson’s Curse. Worst areas for weeds tend to be along watercourses and gullies.
There is a need for an ongoing education campaign for landholders especially ones that are new to the area and are not aware of the implications of allowing weeds on their property to continue to spread. Landcare can play a big part in this.