Description
Holly Leaved Senecio (Senecio glastifolius) is a member of the daisy family. It is a stout perennial, sometimes annual, with stems 1.0-1.5 m, occasionally to 2 m, tall. The stems, which may branch in older plants, can be 80 mm in diameter at the base of large plants. All stems produce flowers on widely spaced branches. Leaves are approximately 1.5 times longer than wide and obovate (widest just above the leaf centre). They are serrated and often coarsely toothed near the leaf stalk and 100-150 mm long at the base of the plants, decreasing to 30-50 mm near the top of the stems, where they are less serrate. Flowerheads range from two to three per plant to several hundred. They are 3.0-5.5 mm long, are yellow in the centre, and are surrounded by mauve petals. The seeds are surmounted by a white, fluffy pappus of bristles.
For further information and assistance with identification of Holly Leaved Senecio contact the herbarium in your state or territory.
Distribution:
In Australia, Holly Leaved Senecio now occurs throughout much of the 260 ha of Jarrah (Eucalyptus marginata), Blackbutt (Eucalyptus pilularis) and Marri (Corymbia haematoxylon) woodlands, and in Allocasuarina open woodlands within the City of Albany, Western Australia. The most affected area is the Mt Adelaide and Mt Clarence nature reserve, where the original infestation was found, but it is also common in the Mt Melville and Lower King reserves. It was also recorded in 1991 and 1999 on the central coast of New South Wales, at Bundeena.
Habit:
Herb
Key points:
- Like many of our serious environmental weeds, Holly Leaved Senecio (Senecio glastifolius) was originally introduced as a garden plant.
- Holly Leaved Senecio could be confused with Wild Cineraria (Senecio elegans).
- It is a prolific seeder and its spread is promoted by fire.
- It has already spread through significant areas of the natural environment near Albany, Western Australia.
- Any new outbreaks should be reported to local councils or state or territory weed management agencies. Do not attempt control on your own.
How it spreads:
The primary mechanism of spread of holly-leaved senecio is seed dispersal, but it is able to take root from fallen branches and vegetative material. Wind dispersal of the seed allows it to spread some distance from the original infestation, and seeds may remain viable in the soil for extended periods of time. Germination is promoted by fire. Fire followed by good rains has proved to substantially promote its spread throughout its current range in Western Australia. It is believed that slashing fire breaks or disturbing the soil in the vicinity of the plant or its seedbank also assists the spread of seeds.
Where it grows:
Holly Leaved Senecio favours open areas, such as open woodland, shrubland, hillsides, coastal dunes, roadsides and near waterways. In South Africa it grows on rocky hillsides, streambanks and marshy ground. It grows well in pastoral areas and is often abundant on old burn sites.
Holly Leaved Senecio is particularly invasive in open damp areas, and has the ability to dominate understorey vegetation in these conditions.
Flower colour:
Purple
Distribution map:
Impacts:
Holly Leaved Senecio is on the Alert List for Environmental Weeds, a list of 28 non native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia’s ecosystem.
The prolific seeding capability of Holly Leaved Senecio and its already proven invasiveness in Western Australia and New Zealand indicate that we need to be aware of this plant to prevent its further spread in Australia. It is currently posing a threat to the global biodiversity hotspots of the Stirling and Fitzgerald River National Parks in Western Australia (CRC 2003). Due to the lack of research into this species it is difficult to know what the specific impacts may be however it is already a serious environmental weed in New Zealand.
Origin:
Holly Leaved Senecio is native to a narrow coastal strip of the Eastern Cape Province of South Africa. Even in its original range it has become a weed of disturbed sites and agricultural land. Holly Leaved Senecio has spread widely throughout New Zealand in the last 20 years.
