Species Overview

Native to: India and Africa
Ganges primrose was introduced into Florida around 1930 for use as an ornamental. It has ecscaped cultivation and can now be found growing wild in natural areas. This Category ll invasive perennial grows and reproduces rapidly; it can flower and produce seeds within 45 days of germination. Ganges primrose can be an erect plant or clambering, about three feet tall at its maxium. It has a weak, hairy stem, with nodes that will root when they touch the ground, furthering its abilty to spread.

Species Characteristics

• Family: Acanthaceae
• Habit: trailing to erect, glabrous to lightly hairy, perennial herb to 3.3 feet tall with weak stems, rooting from the nodes
• Leaves: opposite, simple, ovate, to 3 inches long and 1.5 inches wide, petiolate; margins entire to slightly toothed
• Flowers: purplish-blue (sometimes yellow or white with dark purple streaks), to 2 inches long, arranged along one side of a long terminal spike
• Fruit: hairy, club-shaped capsule to 1” long
• Seeds: 2-4 angular, gray seeds that are dispersed from explosive capsules 
• Distribution in Florida: central and south

Impacts

Ganges violet can smother all vegetation in the herbaceous layer. This plant forms weedy thickets along roadsides and is found in disturbed upland habitats in south Florida. It can be very invasive in developed or natural landscapes. It is a successful colonizer that has invaded across a wide geographical range due to its fast establishment, rapid growth rate and early flowering.

Adapted to a wide range of environmental conditions and tolerates drought, full sun to partial shade, direct exposure to salt spray and a variety of soils. Ganges primrose reproduces by vegetative fragments as well as by seed. It fowers and sets fruit early in its life cycle (at 45 days), and can produce hundreds of explosive capsules per plant. It also reproduces from pieces broken off the main plant, therefore attempts to eliminate it by pulling it can actually spread it if not done carefully. And it also spreads via rhizomes, or underground stems, making it a triple threat.

Ganges primrose is not recommended by UF/IFAS. The UF/IFAS Assessment lists Ganges primrose as a species of caution (requires management to prevent escape) for all parts of Florida. and FLEPPC lists it as a Category ll invasive species.

Regular monitoring and removal of plants can prevent the spread and establishment of Ganges primrose. Programs to educate homeowners on proper plant identification will also reduce the spread of this species. Native alternatives to Ganges primrose for use in home landscaping or natural areas include little hogweed (Portulaca oleracea), pink purslane (Portulaca pilosa), east coast and west coast dune sunflowers (Helianthus debilis) powderpuff (Mimosa strigillosa). 

Remove seed pods and pull seedlings. 

Hand-pulling and removal of entire plants, particularly the roots, is practical for small infestations, therefore tilling is not recommended. All parts of the plant should be disposed of in a trash bag to prevent reinfestation.

There are no known biological control agents for Ganges primrose.