Family: Asteraceae

Origin, Description & Uses
Synedrella nodiflora, commonly known as nodeweed, Cinderella weed, or synedrella, is a low-growing annual herb native to tropical and subtropical regions of the Americas. It has spread widely throughout the tropics and is now naturalized on Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Kahoʻolawe, Maui, and Hawaiʻi Island. First collected on Oʻahu in 1930, this species is commonly found in disturbed sites, gardens, roadsides, pastures, agricultural areas, and other low-elevation habitats. It produces small yellow flower heads and can form dense patches. In some regions it has been used in traditional medicine and as a minor forage plant, though it is generally regarded as a weed.

Risks & Threats
Synedrella nodiflora is naturalized in Hawaiʻi and possesses traits that are cause for concern. It grows rapidly, produces abundant seed, and readily colonizes disturbed areas, allowing it to spread and persist in a variety of environments. These characteristics can enable it to compete with desirable vegetation and potentially alter plant communities. Because tropical island ecosystems are especially vulnerable to invasive species, continued spread of nodeweed could detrimentally impact native habitats and ecosystem functions. This species is already widespread in Hawaiʻi, so efforts should focus on managing existing populations and preventing its use or further spread into areas where it is not yet widely established. When selecting plants for landscaping or restoration projects, low-risk or native alternatives are recommended whenever suitable options are available.

High Risk Traits:

• Broad climate suitability
  
• Thrives in tropical climates
  
• Widely naturalized, including main Hawaiian Islands (except Ni‘ihau)
  
• A lawn and disturbance weed
  
• An agricultural weed of several crops
  
• A potential environmental weed (although impacts in the Hawaiian Islands appear to be minimal)
  
• May be allelopathic
  
• An alternate host of crop pests and pathogens
  
• Reproduces by seeds
  
• Self-compatible
  
• An annual, able to complete its life cycle in 130 to 150 days
  
• Seeds dispersed by wind, water, by external attachment to animals and people, and as a produce contaminant
  
• Prolific seed production
  
• Seeds may remain viable in the soil for at least one year

Low Risk Traits:

• Despite its designation as a significant crop weed, generally regarded as a weed of minor significance in the Hawaiian Islands
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock
  
• Slashing and cultivation provide good control