Solanum americanum (SOLANACEAE) Glossy Nightshade

Weeds to Whack

A cosmopolitan weed throughout the warmer regions of the world.Glossy nightshade is mostly an annual, sometimes a short-lived perennial herb. It grows upright, and the fruits are borne in a relatively upright position which distinguishes it from the similar blackberry nightshade Solanum nigrum which has dull fruit borne pointing downward, with smaller outward pointing sepals.
Photo: Mark Crocker

Flower Close-up

Small, white, star-shaped flowers autumn through to spring, 8-9 mm across, five petals and a yellow central cone in stalked clusters of 4-8 flowers.
Photo: Mark Crocker

Green Fruit

Fruits are spherical, green then shiny purplish-black when ripe, 6-9 mm in diameter.
Photo: Robert Whyte

Flower Close-up

Certainly a weedy solanum, this looks to be the same as the other specimens photographed here. Solanum americanum var. nodiflorum is thought to be native to Australia. This would be hard to verify definitively, as small, common weeds like this might well have stowed away on Cook’s voyages, or even been introduced in pre-colonial times via human traffic to and from Micronesia, south-east Asia and nearby Pacific Islands. Such successful weeds generally need very little material to get a toehold in new regions.

Photo: Robert Whyte