Bonamia dietrichiana

Dietrich's morning glory


Bonamina dietrichiana

Hallier f. 1897

pronounced: bon-NAH-mee-uh dee-trick-ee-AH-nuh

(Convolvulaceae — the morning glory family)


common name: Dietrich's morning glory

Bonamia was named by Louis-Marie Aubert du Petit-Thouars for François Bonamy (1710-1786), French physician and botanist. The Bonamia genus was originally named Breweria, but was transferred to Bonamia in 1897 by Hans Hallier; dietrichiana is named for the remarkable pioneering woman collector Amalie Dietrich (1821-1891), who did a great deal of plant collecting in the area around Mackay and Bowen in the 1860s.

This is a rare plant, and Magnetic Island is about the upper northern limit of its distribution. It is found south from here to the area around Maryborough, and there appears to be a disjunct population in the gulf country of north-western Queensland. The plant photographed is in the outflow area of Butler’s Creek at the northern end of Picnic Bay. The vine has also been found at James Cook University in Townsville, in the University Greek area on the eastern side of the campus. It is also known to grow on some of the Whitsunday Islands.

Dietrich’s morning glory is usually found in vine thickets and vine scrub, among granite boulders. It scrambles over nearby small trees and shrubs, and over the boulders themselves.

The vine can scramble up to about 8 m in height. As can be seen from the photograph of the leaf detail, the alternate leaves and their petioles are covered by dense, fine silvery hairs, on both the upper and the lower surfaces. The shape of the leaves varies from oval to lanceolate, with a cordate base. They are up to about 5 cm long by 3 cm wide. The largest leaves are on portions of the stem away from the flowers.

The flowers, occurring in late summer and early autumn, are the typical morning glory infundibuliform shape, up to about 6 cm across, white, having 5 fused petals that are rather hairy on the underside. There are 5 sepals about 1 cm long, also hairy. The flower has 5 stamens and 2 styles that are fused at the base. Propagation is thought to be effected by hawk moths, and possibly also by the olive-backed sunbirds who have been observed visiting the flowers.

The fruit ripens to a brown spherical capsule about 1 cm long, cupped in the persistent sepals, also brown, and quite stiff. When fully ripe, it dehisces along four sutures, releasing a number of hard triangular seeds that disperse by simply falling to the ground. The vine can also spread by the suckers that emerge from the lateral roots of the plant.


Photographs takenin Picnic Bay 2016
Page last updated 21st October 2018