Family: Malvaceae

Origin, Description & Uses:
Urena lobata, commonly known as Caesarweed or Congo jute, is a shrubby, fast-growing member of the mallow family that is native to tropical and subtropical regions of the world. It typically grows 3–10 feet (1–3 m) tall and has soft, hairy leaves and small pink to lavender hibiscus-like flowers followed by distinctive burr-like seed capsules that readily cling to clothing, fur, and equipment. The species has been used in some regions as a source of fiber for cordage and textiles, and it has a history of use in traditional medicine. It is also occasionally grown as an ornamental or curiosity plant because of its attractive flowers and rapid growth.

Risks & Threats:
Urena lobata is naturalized on Kauaʻi, Oʻahu, and Maui and possesses traits that are cause for concern in Hawaiʻi. It produces abundant seeds that are easily dispersed by animals, people, and machinery, allowing it to spread rapidly into disturbed sites, roadsides, forest edges, pastures, and natural areas. Dense stands can outcompete native vegetation, interfere with restoration efforts, and contribute to the degradation of tropical island ecosystems. Because of these invasive characteristics, planting Urena lobata is not recommended. Where possible, choose a low-risk or native alternative for landscaping or restoration projects. Since this species is already established in parts of Hawaiʻi, landowners and land managers should avoid introducing it to new areas and manage existing populations where feasible to help minimize its further spread and ecological impacts.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Widely naturalized (including Kauai, Oahu, and Maui, Hawaiian Islands)
  
• Disturbance-adapted weed of waste grounds, roadsides, open woodlands, forest margins, coastal dunes, riparian areas, swamps, salt marshes, as well as in pastures and active and abandoned croplands
  
• Agricultural and pasture weed
  
• Potential environmental weed
  
• Other Urena species are invasive weeds
  
• Alternate host of crop pathogens
  
• Tolerates many soil types
  
• Forms dense thickets that exclude other vegetation
  
• Reproduces by seeds
  
• Self-fertile
  
• Reaches maturity in one growing season
  
• Dispersed by barbed spines on fruits that adhere to clothing and fur
  
• Seeds also dispersed by water, contaminated soil and/or contaminated agricultural equipment
  
• May form a persistent seed bank (longevity unspecified)

Low Risk Traits:

• Palatable to browsing/grazing animals (although may be less preferred than other pasture plants)
  
• Non-toxic
  
• Prefers full sun and high light environments
  
• Not reported to spread vegetatively
  
• Herbicides may provide effective control