Indian Toothcup, Toothcup

Quick Facts

Indian Toothcup (Rotala indica) is an upright or creeping, terrestrial or aquatic annual herb.
It prefers wet areas and occurs from 0-1000 m in altitude.
It is not naturalised in Australia.
It is on the AQIS target lists of weeds, insects, plant and animal pests and diseases.
Indian Toothcup is sold as an aquarium plant in Australia.

What Does It Look Like?

What is it?

Indian Toothcup (Rotala indica) is an upright or creeping, terrestrial or aquatic, annual herb with squarish stems 10–40 cm long. The leaves are in opposite pairs, oblong to egg-shaped and 4–15 mm long by 3–5 mm wide, with or without a short leaf stalk.

The flowers occur in the leaf forks and may be solitary or in short dense spikes, each flower having a narrow leafy bract (modified leaf). The sepals (leaf like structures) are fused into a tube, 2–3 mm long, with four triangular tips. The four petals are pinkish or white and are tiny and inconspicuous. The two to six stamens (pollen bearing stalks) are attached deep in the sepal tube.

The two-valved fruit is oval shaped and 1.5 mm by 0.8 mm and contains numerous tiny, pear-shaped seeds (PIER 2008).

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

Flower colour

White, Pink

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Indian Toothcup prefers wet areas such as rice fields, river banks, ditches, and waterlogged grasslands at altitudes from 0-1000 m (PIER 2008).

Are there similar species?

There are no species currently occurring in Australia that are similar to Indian Toothcup.

Why Is It A Weed?

What are its impacts?

Agriculture: Indian Toothcup is a serious weed of rice in Afghanistan, Japan, Korea, Philippines, and Taiwan. It is also troublesome in the United States of America (PIER 2008).

Native ecosystems: If Indian Toothcup was to establish in Australia it would affect native wetlands.

How does it spread?

Indian Toothcup spreads by seeds and plant fragments dispersed by water and attached to waterbirds (PIER 2008).

What is its history in Australia?

Indian Toothcup is not recognised as being naturalised in Australia (AVH 2007). It has been listed on the target lists of weeds, insects, plant and animal pests and diseases (AQIS 2007).

How To Manage It?

Best practice management

Non-chemical control: Land management: Experiments have shown that certain plants, or extracts from them, are able to suppress the growth of weeds in rice paddies, including Indian Toothcup, through allelopathy (inhibiting the growth of other plants by the release of chemicals) (Tran et al. 2005).

Chemical control: Herbicides can also be used to control Indian Toothcup (Kramer 2007).

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