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Asystasia gangetica (L.) T.Anderson 1860
pronounced: a-sys-TAH-zee-uh gan-GET-ih-kuh
(Acanthaceae – the black-eyed Susan family)
common names: Chinese Violet, Creeping Foxglove
Asystasia is Greek, from ασυστασις (asystasis), not united, not meeting, inconsistent, and relates to the fact that the corolla is more or less regular, which is uncommon in the Acanthaceae family – in other words, the genus is the odd-man-out of the family.
The subspecies gangetica (botanical Latin for ‘of or from the Ganges River’) is a very common plant on Magnetic Island, usually found on the banks of drains and ditches, but often invading gardens. Originating in India, it has become naturalized in much of Queensland and the Northern Territory, while the other subspecies, micrantha∗, from Africa, is naturalized around the area of Nelson Bay in NSW. Both subspecies can become very invasive, and are capable of smothering other ground plants. Ssp. micrantha is on the Australian National Environmental Alert List, and should be reported when found. It has caused major problems in the ecosystems of many Pacific Islands. I am not sure whether the white flowers pictured are those of ssp. micrantha, or merely a white variety of ssp. gangetica.
The plant is a spreading herb or groundcover, reaching about 60 cm in height, or up to 3 m if supported on other vegetation. The stems root easily at the nodes, and this enables it to spread quickly. The leaves are simple and opposite, usually up to 8 cm long by 4 cm broad, but may be larger. The fruit is an explosive capsule that starts out green in colour, but dries to brown after opening. Ssp. gangetica has a blue or mauve flower 3–4 cm long, while ssp. micrantha has a 2.5 cm long flower, white on both the inside and the outside except for the middle lobe of the lowest lip, which has purple blotches in two parallel lines down raised ridges on the inside. These lines indicate to the honeybee where to find the nectar. The fruit is about 2.5 cm long, guitar-shaped (with the neck of the guitar attached to the stem) and containing 4 flattened seeds with a conspicuous hook at the base of each. The seeds are hairless, bone-coloured to brownish black, about 5 mm long and 1 mm thick. Both subspecies flower over a long period.
In some parts of Africa, the leaves are used as a vegetable and also used as a herbal remedy in traditional medicine, especially for the management of asthma. It is quite an important plant for honeybees, butterflies and other insects. In southern Africa there are at least 6 species of butterfly that use the ssp. micrantha as a larval food plant.
Both subspecies can be very useful for mass planting in gardens, under large trees or in borders in full sun, semi-shade or full shade. Their introduction into so many countries has been for that purpose, but, alas, the plant has escaped from the garden and got out of control.
The larvae of several species of Australian Lepidoptera use this as a food plant, including:
• the Blue-banded Eggfly Hypolimnas alimena,
• the Diadem Hypolimnas misippus, and
• the Australian Rustic or Leafwing Doleschallia bisaltide.
∗ μικρος (mikros), small, and ανθος (anthos), a flower, anther
Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.
Photographs taken in Picnic Bay 2011, 2012
Page last updated 9th October 2016