Australian Tropical Rainforest Plants - Online edition

Thunbergia alata Bojer ex Sims

Slender Vine
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Leaves and Flowers. © CSIRO
Flowers. © CSIRO
Leaves and fruit. © CSIRO
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination on left and 1st leaf on rig. © CSIRO
10th leaf stage. © CSIRO

Sims, J. (1825) Curtis's Botanical Magazine 52 : t. 25. Type: Robert Barclay, Esq. .. received the seeds from the Mauritius, through Mr. Telfair, .. and stated to be native of the islands of Zanzebar.

Common name

Pullet's Eye; Black-eyed Susan


Usually a slender vine.


Leaf blades about 3-8 x 3-7.5 cm, petioles about 2.5-3.5 cm long, distinctly winged over much of their length. Leaf blades hairy on both the upper and lower surfaces.


Flower stalks long and slender with two large green leafy bracts about 15-20 x 15 mm at the apex +/- enveloping the flower bud and the lower part of the flower at anthesis. Calyx consists of 10-12 subulate lobes, each clothed in short hairs. Corolla lobes orange to yellow, throat of the corolla reddish brown to black, rarely orange-yellow, and hairy. Anthers hairy on one side, resembling a tooth brush, and with a spur on one locule. Stigma +/- funnel-like at the tip and draining into a lateral cup further down.


Fruits enveloped in two large persistent bracts, each about 18-20 x 15 mm. Fruits globular at the base, about 8 mm diam., but ending in a laterally compressed beak at the apex. Beak about 13 mm long. Outer surface of the fruit clothed in short translucent erect hairs. Seeds usually 4 per fruit. Seeds about 4 mm diam., testa surface rugose. The margin of one cotyledon is folded around or enveloping the other cotyledon.


Cotyledons +/- orbicular, about 18-22 mm diam., base auriculate. Cotyledons 3-veined at the base or palmately veined. Both the upper and lower surfaces clothed in short erect hairs. Hypocotyl hairy. First leaf blades cordate to triangular, apex mucronate, base cordate, both the upper and lower surfaces clothed in short hairs. Leaf blade margins with a few teeth towards the base. Petioles winged for their entire length. At the tenth leaf stage: leaf blade +/- cordate, apex acute with a thickened point, base cordate-hastate. Midrib hairy, raised in a depression on the upper surface. Margin with 5-8 teeth on each side. Petiole hairy, winged, about as long as the leaf blade, base of the petiole twisted. Both the upper and lower leaf blade surfaces clothed in colourless hairs, those on the lateral veins confined to the apical half of the leaf blade. Seed germination time 12 days.

Distribution and Ecology

An introduced species, originally from Africa, now naturalised in NEQ, CEQ and southwards to New South Wales. Recorded from CYP. Altitudinal range from near sea level to 800 m. Usually grows in disturbed areas around settlements but also found on rain forest margins. Flowers profusely but seed set usually not comparable.

Natural History & Notes

Commonly cultivated and now a very common weed which flowers profusely for most of the year.

A food plant for the larval stages of the Blue Argus Butterfly. Common & Waterhouse (1981).

RFK Code
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