Urena lobata, Caesar's Weed
Urena lobata, commonly called Caesar's Weed is one of Florida's more attractive noxious weeds. It can be found in most natural areas dominating the areas that get ample sunlight. Its charming pink flowers catch hiker's eyes in the heat of the day then disappear as the light fades.
Urena lobata is a subshrub (a woody bush that thrives in stressful environments) native to temperate and tropical Asia, Australasia, and India. It is listed as Invasive by the University of Florida IFAS Assessment of Non-native Plants.
There are many plants in the family Malvaceae like Urena lobata that are grown for ornamental purposes including Hibiscus, Abutilon, and Alcea. Cotton (Gossypium hirsutum) is also in this family and looks very similar to Caesar's Weed though in Florida cotton does not grow as tall as its cousin.
Not only does the Malvaceae plant family contain many ornamentals, but there are also many weedy species such as Malva, Malachra, and Urena.
Caesar's Weed grows as an erect shrub to 10 feet (3 m) in height. The plant is single stalked, with free-branching stems that comprise a bushy appearance. The leaves are palmately lobed, pubescent with stellate hairs, and 4-8 cm long.
The Flowers of Urena lobata are born in axillary clusters, pinkish-violet, about 1 cm across. Fruit is pubescent with hooked bristles or barbs that cling to clothing or fur.
Caesar's Weed invades disturbed areas, pastures, eroded area, and perennial crop plantations. The species does not compete well in tall grass nor will it grow in the shade. Caesar's Weed tolerates salt spray but will not grow in saturated soils. Aggressive growth can lead to heights of 2-7 feet in the first year with ample reproduction.
There are no biological controls for Urena lobata. Old-fashioned removal by hand has worked for me. Use rough rubber or leather gloves and grab the plant near ground level to extract its impressive roots.