Quick Facts

Quick facts

• Tutsan (Hypericum androsaemum) is native to western and southern Europe.
• It was introduced to Australia as a garden plant and has become a serious environmental and agricultural weed in the south-east.
• It is a yellow-flowered, soft-wooded shrub to 1.5 m high forming dense thickets that smother and shade out native vegetation and prevent the regeneration of native plant species.
• The seeds of this plant are spread by birds, foxes and water, and as a contaminant of soil, vehicles, machinery and agricultural produce.
• A variety of methods may be used to control Tutsan including hand-pulling or digging, ploughing (in agricultural situations), herbicide application and biological control.

What Does It Look Like?

What is it?

Tutsan (Hypericum androsaemum) is a soft-wooded, usually curry-scented shrub that can be low and sprawling or more or less upright that grows up to a height of 1.5 m. The stems are green or red, hairless and tend to arch with age. The leaves are stalkless, green on the upper surface, paler greyish-green below, frequently blotched red, hairless, 2–12 cm long, 1–8 cm wide, and arranged on the stems in opposite pairs. They are more or less oval in shape, broad towards the base and narrowly tapered towards the tip.

The flowers are borne in clusters of 3–15 at the tips of branches. Individual flowers are about 2–3 cm wide with five yellow petals and numerous stamens (stalks or filaments containing pollen) united at their bases into five bundles opposite the petals.

The fleshy, berry-like fruit is more or less spherical with a more or less flat or slightly depressed top, c. 1 cm wide, green initially, then turning red and eventually maturing purple-black. The seeds are reddish-brown, more or less cylindrical, c. 1 mm long and c. 0.5 mm wide (Robson 1985; Webb et al. 1988; Walsh 1996; Muyt 2001; National Herbarium of Victoria 2008; Reid 2008 pers. obs.).

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

Flower colour

Yellow

Growth form (weed type/habit)

Shrub

Where it currently grows? Preferred habitat

Tutsan favours humid and subhumid warm temperate regions with high rainfall (more than 750 mm per year). As long as sufficient moisture is available, it can establish in conditions ranging from deeply shaded to open and sunny. It invades disturbed and undisturbed sites, particularly in cool, moist forests, along roadsides and beside watercourses. It also spreads to pastures adjoining forests. Tutsan infests southern slopes more frequently than northern slopes, probably because it is more tolerant of shade than other plants (Parsons & Cuthbertson 1992; Walsh 1996; Muyt 2001).

Are there similar species?

Tutsan is most likely to be confused with other Hypericum spp. that have already established as weeds or have the potential to do so. (Reid 2008 pers. obs.). The shape of its fruits should readily distinguish it from its close relative Tall Tutsan (H. x inodorum) (Reid 2008 pers. obs.). Tall Tutsan fruits are more or less oval in outline with domed or pointed tops whereas Tutsan has more or less spherical fruits with flattish or slightly depressed tops (Webb et al. 1988). Rose of Sharon (H. calycinum) is a subshrub with similar leaves to Tutsan but much larger flowers (7-9 cm wide). Canary Island St. John's Wort (H. canariense) is taller (to 2 m high) than Tutsan and has much narrower leaves (mostly less than one cm wide). Square-stem St. John's Wort (H. tetrapterum) is a herb, or subshrub, with square stems. Tutsan has cylindrical stems. St. John's Wort (H. perforatum) and Tangled Hypericum (H. triquetrifolium) are both herbs with narrow leaves that are usually well under one cm wide (Walsh 1996; Reid 2008 pers. obs., Webb et al. 1988).

It may be necessary to consult an expert to correctly identify specimens to species level – contact the herbarium in your state or territory.

Why Is It A Weed?

What are its impacts?

Native ecosystems: Tutsan is rated a very serious threat to native vegetation in damp and wet sclerophyll forest, riparian vegetation, warm temperate rainforest and cool temperate rainforest (Carr et al. 1992). Infestations spread rapidly and can form dense closed stands that smother and out-compete native species, including those forming the ground layer and smaller shrubs, and also inhibit the regeneration of native vegetation (Muyt 2001).

Agriculture: Tutsan invades pastures, especially when they have been overgrazed, and may lead to the weed out-competing and displacing most other plants (Parsons & Cuthbertson 1992). It was regarded as the cause of death of cattle in Auckland, New Zealand, but feeding trials indicated it was unpalatable and it was concluded that in general it must be regarded as non-toxic (Connor 1977).

How does it spread?

The main means of spread of Tutsan in Australia was originally as a garden ornamental plant in the late 1800s. It is believed to have spread from cultivation by a variety of means. The seeds are spread by birds and animals, including foxes. The seeds are also spread by water and as a contaminant of soil, vehicles, machinery and agricultural produce (Webb et al. 1988; Parsons & Cuthbertson 1992; Muyt 2001).

What is its history in Australia?

The first Australian record of Tutsan is in a catalogue of plants growing in the Royal Society's Gardens in Hobart, Tasmania in 1865. It was introduced to Australia as an ornamental plant, apparently because of its attractive yellow flowers and reddish leaves (Parsons & Cuthbertson 1992). The first naturalised record for Australia is in 1907 from near Apollo Bay in the Otway Range in western Victoria where it was noted to be spreading rapidly in the district (National Herbarium of Victoria 2008).

How To Manage It?

Best practice management

In bushland situations, the best time to treat Tutsan with the various suitable control methods is in spring before the fruit develops.

Non-chemical control: Manual control: Plants can be hand-pulled or dug out ensuring that the roots are removed to prevent regrowth.

Mechanical control: Large patches in agricultural areas are best ploughed in autumn and cultivated whenever new growth appears (Parsons & Cuthbertson 1992; Muyt 2001).

Chemical control: In situations where physical removal is difficult or where minimal soil disturbance is desired, plants can be treated using the cut-paint method. This involves cutting plants back to near ground level and painting the cut stems with a suitable herbicide. Any pulled, dug or cut plant material with semi-ripe or ripe fruit should be disposed of safely. Tutsan can also be sprayed with selective or non-selective herbicides but selective herbicides generally provide better results. Avoid using herbicide treatments in winter when Tutsan is semi-dormant (Muyt 2001).

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)

Tutsan produces flowers mainly from October to March and fruits from October to August (National Herbarium of Victoria 2008). Most fruits ripen from late summer to autumn. Seeds germinate in autumn and plants reach sexual maturity within two years. Tutsan is semi-deciduous and largely dormant over winter. New growth is produced in spring (Parsons & Cuthbertson 1992; Muyt 2001).

Where Is It Found?

Which states and territories is it found?

ACT, NSW, TAS, VIC

What areas within states and territories is it found?

Tutsan is a common weed in wetter parts of Victoria, including the Otway Ranges, Dandenong Ranges, Eastern Highlands and Gippsland Highlands (Walsh 1996; National Herbarium of Victoria 2008). In New South Wales it is recorded from the Central Tablelands, Southern Tablelands (including the Australian Capital Territory) and Central Coast. It is especially common in the mountains west of Sydney including the Jenolan Caves, Katoomba and Leura areas (AVH 2008; Chapple 2008 pers. comm.) It is widely dispersed in Tasmania with records suggesting localised occurrences (AVH 2008, Tasmanian Herbarium 2008). In Western Australia, Tutsan is recorded from Albany and is (doubtfully) naturalised there (Hussey et al. 1997).

Where does it originate?

Tutsan is native to western and southern Europe including Great Britain, Ireland, Portugal, Spain, France and Italy and extends eastwards to Turkey and Iran (Tutin et al. 1968; Robson 1985).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

VIC, WA

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?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Hypericum androsaemum

Other scientific names (synonyms)?

Does it have other known common name(s)?

Sweet Amber