Quick Facts

Quick facts

• Chilquilla (Baccharis glutinosa) is currently a species of relatively low infestation level over an area of approximately 4 ha in Victoria.
• Plants are apparently all female at the site and probably do not produce viable seed.
• Plants are able to resprout from the rootstock and are thus able to survive significant disruption.
• Future outbreaks of Chilquilla are likely to be confined to areas near waterways or to seasonally inundated sites.
• It has the potential to become a weed of irrigated crops in Australia.

What Does It Look Like?

What is it?

Chilquilla (Baccharis glutinosa) is a robust herb or sub-shrub to about 1 m high arising from a strong, branching rootstock that is capable of giving rise to new aerial stems. Stems appear to die down annually. The main stem is erect, usually unbranched in the lower half and with only a few erect branches in the upper part. Leaves are mostly 2–8 cm long and 2–8 mm wide, usually widest above the middle. There are usually 3–8 narrow teeth or lobes on either side, but the smaller leaves amongst the flower heads often lack teeth. Stems and leaves lack hairs, but may be covered by a slightly sticky resin.

Flowers are borne in cup-shaped heads at the ends of the stems, the heads usually about 5–15 together in loose clusters. Male and female flowers are on separate bushes. Individual flowers (florets) are surrounded by 2 or 3 rows of narrow scale-like bracts (modified leaves) 1–4 mm long. These are hairless, pale green and often reddish- or purple-tipped. There are no ray-florets (the spreading petal-like florets that are characteristic of 'typical' daisies). Old florets develop a tuft of silky hairs (a pappus) to about 4 mm long (Parsons & Cuthbertson 1992; Walsh 2007, pers. comm.).

For further information and assistance with identification of Chilquilla contact the herbarium in your state or territory.

Flower colour

White

Growth form (weed type/habit)

Herb, Shrub

Where it currently grows? Preferred habitat

In Victoria Chilquilla occurs in pasture and has been recorded in an oat crop (National Herbarium of Victoria 2007). In this area, some plants grow in a shallow drainage channel.

In the western states of the United States it has been reported to form dense thickets along borders and banks of moist areas interfering with irrigation (US Army Corps of Engineers 2002). In its native Argentina the species appears to favour riparian sites and adjacent areas prone to seasonal inundation (Perelman et al. 2003).

Are there similar species?

Similar species to Chilquilla include the common weeds, Aster-weed (Aster subulatus) and the Fleabanes (Conyza spp.), particularly C. sumatrensis and C. bonariensis. The latter two species are somewhat hairy along the stems, while the first has short, but distinct ray florets. Neither aster-weed nor fleabanes have separate male and female plants, nor do they resprout from a branched rootstock (Walsh 2007, pers. comm.).

Why Is It A Weed?

What are its impacts?

Chilquilla is one of seventeen sleeper weeds identified by the Bureau of Rural Sciences (following consultation with the Australian Weeds Committee) which could have nationally significant impacts on agriculture if allowed to spread.

Agriculture: Currently the impact of Chilquilla is relatively slight, reducing somewhat the capacity of the Victorian site to carry stock and/or produce cereal grain. Like other Baccharis spp. it could become persistent weeds in flood plains, old fields, or similar habitats (Cunningham & Brown 2006). It is a weed of irrigated crops overseas and climatically suited to irrigation regions in Australia (Cunningham et al. 2006).

How does it spread?

The related groundsel bush (Baccharis halimifolia) spreads by its seeds which are dispersed by wind and water, assisted by the fluffy pappus (Parsons & Cuthbertson 1992). However, because Chilquilla does not appear to produce seed in Victoria, dispersal at this stage appears to be confined to transport of whole plants or fragments of the regenerative rootstock (National Herbarium of Victoria 2007; Walsh 2007, pers. comm.).

What is its history in Australia?

Chilquilla was first reported in Victoria in 1988 (National Herbarium of Victoria 2007), but was known at the site for several years before that time. It is likely to have originated as a contaminant in a pasture or crop seedlot originating from South America, the United States or South Africa (Walsh 2007, pers. comm.).

How To Manage It?

Best practice management

Non-chemical and Chemical control: Limited control of Chilquilla has been attempted at the Victorian site, including slashing, grazing and limited chemical application (DPI 2004).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Flowers of Chilquilla have only been reported in November and April, but it is likely that flowers are produced through the intervening months (National Herbarium of Victoria 2007). Stems probably die back in late autumn or winter, and resprout the following spring. It is not known how long it might take from germination of seed to reproductive maturity (Walsh 2007, pers. comm.).

The plants in Victoria appear to be all female and so do not produce seed (Walsh 2007, pers. comm.). Like all Baccharis species, male and female flowers are carried on separate plants, so, without males nearby, it is unlikely that seed is produced.

Where Is It Found?

Which states and territories is it found?

VIC

What areas within states and territories is it found?

Chilquilla is currently known only from an infestation of about 4 ha on private land near Maryborough, Victoria (National Herbarium of Victoria 2007). Future potential spread of the plant is probably confined to relatively moist, warm-temperate to subtropical areas (Cunningham & Brown 2006). However, Baccharis glutinosa has been known in Victoria for over 20 years and in this time has not spread beyond its original location. This may be due to spread being entirely by rhizome given that only female plants have been observed at the site (VicFlora 2018).

It is also a weed of the western part of the United States and in South Africa (Herman et al. 2000).

Where does it originate?

Chilquilla is native to Chile, Argentina and Brazil (Zdero et al. 1990).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

Not declared in any Australian state or territory

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

YES

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Baccharis glutinosa

Other scientific names (synonyms)?

Baccharis pingraea DC.

Does it have other known common name(s)?

Chilquilla