Cassia (Senna pendula var. glabrata)

Also known as: senna

Cassia is tall, spreading shrub. It is a popular garden plant that invades bushland and banks of watercourses.

Profile

How does this weed affect you?

Cassia is popular garden plant that invades native ecosystems, particularly in coastal areas. It is a fast growing plant that can suppress the growth of native species and displace them. It produces large amounts of long-lived seeds.

Where is it found?

Cassia is native to Brazil and Paraguay. It is widely distributed through eastern parts of NSW. It is most common along the coastal or sub-coastal regions of NSW and Queensland.

How does it spread?

Cassia is spread by seed and sometimes by suckers.

What does it look like?

Cassia is an upright, spreading or sprawling shrub usually growing 2-4 m tall, but occasionally reaching up to 5 m. It is distinguished by the absence of spines and prickles.

The stems are multi-branched and become woody with age. Younger stems are green and sparsely hairy, but become hairless and darker as they mature.

Leaves

The compound leaves (made up of leaflets) are 4-8 cm long and are alternately arranged along the stems and borne on stalks 20-40 mm long. Each leaf is composed of 3-5 pairs of dark green leaflets with rounded tips. These leaflets are egg-shaped to oval, with those closer to the stem generally being smaller. They are almost hairless and have a prominent lighter coloured middle vein. There is a small cone shaped gland between the two lowest leaflets of each leaf.

Flowers

The pea-like flowers are bright yellow, about 30 mm across, with five large petals. They are borne in clusters at the tips of the branches, and each flower is on a stalk. These flowers have two or three prominent curved stamens, four or five smaller stamens, and as well as three tiny petal-like structures at their centres.

Fruit (pods)

The fruits are cylindrical pods that hang downwards and are 10-20 cm long. These pods turn from green to pale brown as they mature, contain 5-40 brown seeds.

What type of environment does it grow in?

Cassia is a weed of waterways, gardens, disturbed sites, waste areas, roadsides, closed forests, forest margins and urban bushland in tropical, subtropical and warmer temperate regions.

References

Environment.gov.au (2014). Weeds search. Available at: http://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=16954# (Accessed November 2014).

Hosking JR, Sainty GR, Jacobs SWL and Dellow JJ (in prep). The Australian WeedBOOK.

Control

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.

PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 1 part per 1.5 parts of water
Comments: Stem injection/cut stump application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 200 mL glyphosate per 10 L water
Comments: Spot spray application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L with Metsulfuron-methyl 600 g/kg (Various products)
Rate: 200 mL glyphosate plus 1.5 g metsulfuron-methyl per 10 L water
Comments: Spot spray application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

PERMIT 9907 Expires 31/03/2020
Metsulfuron-methyl 600 g/kg (Brush-off®)
Rate: 1.0–2.0 g metsulfuron-methyl per 10 L water
Comments: Spot spray application.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High

Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area	Duty
All of NSW	General Biosecurity Duty All plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.

For technical advice and assistance with identification please contact your local council weeds officer.
For further information call the NSW DPI Biosecurity Helpline on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au

Reviewed 2014