Native to: India, tropical Asia, Africa and South America
Caesar’s weed was introduced to the Caribbean region by European voyagers in the eighteenth century likely as a fiber crop and for its medicinal properties. It was documented and noted to have escaped cultivation in Florida by the late 1800s. As a member of the Malvaceae family which includes hibiscus and rosemallows, it has an attractive pink flower and can sometimes be confused with the native Virginia saltmarsh mallow (Kosteletzkya pentacarpos) of the same family.
Habit: erect shrub that grows up to 10 feet in height. The plant is single stalked, with free-branching stems that comprise a bushy appearance.
Leaves: simple, alternate, with the upper surface rough and the lower surface grayish, broadly ovate, often with 3-5 shallow, angular lobes at apex.
Flowers: small, showy, hibiscus-like, solitary on short stalks in leaf axils, rose or pink, darker at the base.
Fruit: small, barbed, spiny capsules that cling to clothing or fur.
Seeds: 1 dark brown seed is contained in each fruit
Distribution in Florida: widespread through the peninsula, and spreading into the panhandle
Spread readily by the bristled fruits that cling to clothing, fur, and feathers, Caesar’s weed invades disturbed areas, pastures, perennial crop plantations, forests, hardwood hammocks, and even coastal habitats. It tolerates salt spray and moderately saturated soils. Having an aggressive habit, Caesar's weed grows rapidly and can reach 2 to 7 feet by the end of the first year. It can form dense thickets, outcompeting native plants and altering ecological community diversity and function.
Prevent the spread of seeds by avoiding walking or driving though heavily infested areas. When this is unavoidable, be sure to clean all clothes, gear, and equipment.
Shade will help to deter growth and limit seedling establishment. Mulches or other ground cover will also prevent seed germination. Hand pull seedlings and young plants.
Remove fruits before management or thoroughly decontaminate any equipment used in infested areas.
No known biological controls for this species.
Foliar applications of 1% 2,4-D, 1% Garlon 4, 1% Vista XRT, or 0.15% Milestone (1 fl oz per 5 gallons of water) are effective, even on mature plants. Source: Integrated Management of Non-Native Plants in Natural Areas of Florida