pronounced: ip-oh-MEE-uh IN-dik-uh
Ipomoea is from the Greek ιψ (ips), a worm, possessive form ιπος (ipos), and 'ομοιος (homoios), like; indica is, of course, ‘from India’.
This is a perennial vine native to Hawaii and the New World tropics, but it can be found throughout the tropical and warm areas of the world as an introduced species. It has become invasive both in Australia and New Guinea. Vigorous and fast-growing, this twining climber will clamber to the top of the tree canopy and form a dense blanket of foliage over all other vegetation.
The large light-green leaves have a broad-ovate lamina, 4 – 17 cm long, 3 – 15 cm wide, the apex acuminate, the base cordate, with margins from entire to deeply 3-lobed. The upper surface has short appressed hairs, the lower surface is silky-tomentose, and the petiole is 3–13 cm long.
Large trumpet-shaped flowers are produced through most of the year. The corolla is infundibuliform, 6–8 cm across, violet-blue with paler mid-petaline bands and a darker throat. There is a thickened portion in the centre of each petal, and the petals are fused.
The seed capsule is depressed-globose, about 1 cm in diameter, 3-locular. The seed rarely if ever sets in Australia, and the plant spreads vegetatively. A major cause of the spread is the dumping of plants that have been chopped down. Pieces of stem that touch the ground will put down roots, especially on the edges of bushland. This vine invades fragile creek-lines and rainforest edges. growing rapidly to the canopy, blocking light, reducing photosynthesis, encouraging disease, preventing germination, and bringing down trees by its sheer weight. This vine and others like it are in the forefront of ecosystem destruction. It has had very serious effects in parts of the Blue Mountains area of NSW.
Many Ipomoea species, including this one, contain alkaloids with psychoactive potential. One of these, Ergonovine, is similar in structure to LSD. Ergonovines are used medically in obstetrics to prevent post-birth bleeding. Uncontrolled ingestion can cause hallucination, miscarriage, liver damage, brain damage, and potentially heart attacks and strokes.
In nature, these alkaloids work to prevent insect attacks on the leaves, and there are few natural grazers on Ipomoea species. This is a great advantage in assisting their spread and prevalence as a weed species outside their natural range. That said, there are a few caterpillar species that will feed on them, including those of the Convolvulus Hawk Moth Agrius convolvuli.
This plant is one of those collected in 1770 by Banks and Solander during the voyage of the Endeavour. It was collected at the Endeavour River (Cooktown). As it is not a native species, it must have been introduced there by someone.