Ipomoea triloba

pink convolvulus


Ipomoea triloba

L. 1753

pronounced:  ip-oh-MEE-uh try-LOW-buh

(Convolvulaceae — the morning glory family)


common names: pink convolvulus, Aiea morning glory, little bell

Ipomoea is from the Greek ιψ (ips), a worm, possessive form ιπος (ipos), and 'ομοιος (homoios), like - like a worm. In triloba, tri- is the Latin prefix for three, and λοβος (lobos) is Greek for ‘the lobe of the ear’ – ‘having 3 lobes’. In the second common name, Aiea is situated in Hawaii. Aiea’s main claim to fame is that, with 41.41% of its residents reporting Japanese ancestry in the last population census, it contains the largest concentration of ethnic Japanese in the USA.

This is yet another species of imported convolvulus that scrambles over anything in its path. A native of the West Indies, it is now weedy throughout most of the tropics. Here on Magnetic Island, I have seen it mainly in vacant allotments and on roadsides, climbing over grasses, weeds and shrubs up to a height of not much more than a metre. Generally, it is found in upland cultivated crops, grasslands, waysides and waste places, and, because of its creeping, climbing habit, may overwhelm other vegetation in farmers’ fields and in natural areas. It is found in various habitats from sea level to 750 m altitude, from open, sunny hillsides to relatively dense forests, in partial sun or deep shade. It is very fast-growing.

It is an annual herb with twining stems 1 – 3 m long, glabrous except for the inflorescence. The stems are somewhat angled, about 3 mm thick, with milky sap. The leaves are broadly ovate to almost circular in shape, entire, coarsely dentate to more-or-less deeply 3-lobed (the centre lobe may be pointed), the base broadly cordate. The leaves are 4 – 11 cm long, and often nearly as wide; the petiole is slender, 3 – 10 cm long, glabrous or sometimes bearing minute tubercles.

The inflorescences are dense umbellate cymes, 1- to several-flowered. The tubular bell-shaped flowers are each about 2 cm long, and less than 2 cm in diameter. I understand that they can be quite variable in colour, in shades of pink, red or lavender, with or without white markings; but all the ones I have seen here are pink with purple centres. The stamens and pistil are included, and the ovary is pubescent. The stigma is 2-lobed.

The capsule is more-or-less globular, 5 – 6 mm in diameter, bristly pubescent, and apiculate, 2-loculed, 4-valved. There are 4 or fewer seeds, dark brown, about 3.5 mm long, 6 mm in diameter.


Photographs taken in Picnic Bay 2010
Page last updated 20th January 2019