About Thunbergia grandiflora (Roxb. ex Rottler) Roxb.
Thunbergia grandiflora (Roxb. ex Rottler) Roxb. plants can reach around 20 meters in height. They have an extensive long root system with a deep taproot that can grow as large as a small car. Their opposite, stalked leaves have a rough surface and vary widely in shape: they may be triangular or ovate, and their margins can be toothed, lobed, or entire. Leaves grow up to 200 mm long and 60 mm wide, and are typically smaller than leaves of the very similar species Thunbergia laurifolia. Its flowers range from blue to mauve, measure around 8 cm across, and have a 4 cm long tube that is pale yellow on the inside. After flowering, the plant produces seed-containing pods that eject their seeds several meters when ripe. Thunbergia grandiflora can also reproduce from plant segments that are washed down watercourses. For cultivation, this species requires a minimum temperature of 10–13 °C (50–55 °F). In temperate regions, it is grown as a houseplant, and has received the Royal Horticultural Society's Award of Garden Merit. The species has become a serious environmental weed in Australia, growing on disturbed land along watercourses and in the wet tropics where it smothers other native vegetation. It is commonly found growing north of Sydney, where it has been cultivated for many years.
