Asystasia gangetica subsp. gangetica.
Asystasia gangetica is a variable species with two subspecies (subsp. gangetica and subsp. micrantha) described although not all recognise them regarding them as synonyms of A. gigantica.
The general consensus seems to be that Asystasia gangetica subsp. micrantha is a synonym for A. gangetica and flowers have a white corolla with 2 purple lines on the lower lobe.
The subsp. gangetica has pink` or mauve flowers.
The other Asystasias occasionally seen are Asystasia travancorica with blue and purple flowers and the native Asystasia australasica from Northern Queensland.
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Asystasia gangetica subsp. gangetica.
Chinese violet, from India and Sri Lanka is occasionally seen in Brisbane gardens.
It is naturalised, and an environmental weed in Northern Queensland.
The perennial herb or sub-shrub has many branches from the base.
Erect stems are up to 50 cm long but with support they can scramble higher.
Young green angled stems have few to many small hairs that lie along the surface.
The simple opposite leaves, on a petiole up to 3 cm long are in 4 ranks.
The petiole bases are joined by a ridge around the stem.
The ovate, circular or lance-shaped blades are up to 5 cm long and 3 cm wide.
The base is flat or rounded, the tip a long tapering point and the edges have shallow lobes.
There are scattered to dense hairs mainly on the blade base.
Terminal inflorescences are spikes up to 10 cm long.
The one-sided racemes have 8 to 10 flowers that open from the base first.
The peduncles, around 4 cm long have small triangular bracts and the pedicels, 1 to 2 mm long have similar bracteoles 1 mm long.
The calyx has a short tubular base with 5 narrow lobes up to 7 mm long with few to dense tiny hairs.
The corolla is up to 4 cm long and 3 cm across.
It has a narrow tubular base and a wider funnel-shaped throat with 5 spreading lobes.
The corolla is typically mauve, pink or purplish with a paler throat.
The slightly longer lower lobe, and the adjacent throat are darker and wrinkled.
Plants occasionally have pure white or cream flowers with the white form known as Asystasia gangetica ‘Alba’.
The 4 stamens are in 2 pairs of one long and one short.
In each pair the joined bases of the filaments insert at the base of the throat.
The superior ovary has 2 locules each with 2 ovules.
The long style has 2 small stigma lobes.
The anthers and stigmas lie just under the base of the upper lobes.
The fruit are brown club-shaped capsules under 3 cm long with up to 4 seeds in the swollen end.
Capsules have few to dense tiny hairs with or without glands.
The capsules open explosively and the seeds are thrown out by their jaculator.
The flattened seeds have a finely nodular surface and an irregular toothed edge.
J.F.
