The genus Asystasia includes both a weed and creeper plants with lovely flowers, writes Elaine Yim
ASYSTASIA may sound like the name of a fairy tale princess in a faraway land but it is the genus name of a few fascinating plants.
One is a common weed many of us would have encountered during our morning walks, hiking or camping trips. The others are beautiful ornamental creeper plants with lovely flowers. All of them attract wildlife such as bees, butterflies and even goats.
PLANT PROFILE
Scientific name: Asystasia gangetica
Synonyms: Asystasia coromandeliana, Justicia gangetica
Family: Acanthaceae
Common names: Chinese Violet, Coromandel, Creeping Foxglove, Ganges Primrose, False Snapdragon
The Chinese name is intriguing. It’s called kuan ye shi wan cuo. Kuan ye means “broad-leaf”, shi wan means 100,000 and cuo means “wrong”, “criss-cross”, “inter-locked” or “intertwined”. I guess that cuo refers to its dense creeping habit.
The genus name Asystasia is derived from the Greek words “a” and “systasia” meaning “not consistent”, in reference to the flowers which are radially symmetrical. This feature is quite different from other members of the Acanthaceae family which are characterised by bilaterally symmetrical flowers. There are about 70 species of flowering plants in this genus.
Gangetica refers to the Ganges river in India. The synonym A. coromandeliana is named after the Coromandel Coast in India.
THE PLANT
Asystasia gangetica is an evergreen, ever-flowering herbaceous perennial creeper native to the tropical regions of Africa, India and Peninsular Malaysia.
There are several forms, asystasia gangetica with purple flowers, asystasia gangetica Alba with white flowers and asystasia gangetica Variegata with variegated leaves. These three can be grown as garden ornamentals.
Asystasia gangetica ssp. Micrantha, meanwhile, is a subspecies regarded as a noxious weed in many places.
The plant can grow from 0.3-1m tall. The leaves are simple and oppositely arranged. They are oval-shaped with a round to heart-shaped base and pointed tips. Each leaf is about 8cm long by 4cm wide and light green in colour. The stems are square and hairy with nodes that can root easily.
Flowering occurs freely the year round. The funnel-shaped flowers are borne on branch tips in terminal inflorescences called racemes. The flowers can be white, yellow or purple in colour. They attract bees, birds and butterflies.
The fruit is a flat capsule with one to four seeds. The capsule ripens from green to brown. Dried capsules explode releasing the seeds inside.
ASYSTASIA GANGETICA SSP. MICRANTHA
Its Malay name is Akar Ruas-Ruas, Ara Songsang, Rumput Pengorak or Rumput Israel.
This common weed can be found growing wild along roadsides, rubbish dumps, vacant lands and in open areas along jungles. It’s a fast grower with high shade tolerance.
It self-seeds easily and the stems root easily when in contact with moist soil. Hence, it can become quite invasive and difficult to eradicate. It’s a dreaded weed in orchards, oil palm and rubber plantations where it can become so rampant that chemical pesticides are necessary to control it. Otherwise, it will compete with the main crop for nutrients with an adverse effect on yield and production costs.
It has become a noxious weed in Indonesia, Australia and the Pacific Islands. It is known as rumput kambing (goat grass) because it is a popular forage food for goat and cattle. The leaves and shoots can be eaten raw as ulam, stir-fried or boiled into soup. It is also used as herbal medicine in Africa.
It is a host plant for butterflies such as Jacintha Eggfly (Hypolimnas bolina), Autumn Leaf (Doleschallia bisaltide) and Blue Pansy (Junonia orithya).
HOW TO GROW
It can be grown in a container or applied in mass planting on the ground as a border plant or ground cover. This plant is suitable for the shady areas under large trees.
TIPS
• PROPAGATION: By seeds and cuttings.
• SUNLIGHT: Full sun to semi-shade.
• MEDIUM: Fertile, well-drained soil.
• WATER: Moderate. It is quite drought tolerant.
• FERTILISE: Apply a balanced compound fertilizer once a fortnight.
• MAINTENANCE: Prune the plant into a compact shape.
• PEST AND DISEASES: Not a problem.