Family: Caryophyllaceae

Cerastium fontanum, commonly known as common mouse-ear chickweed, is a low-growing herb native to Europe and parts of western Asia. It forms soft, spreading mats with small, oval, fuzzy leaves and delicate white, five-petaled flowers. This species thrives in cool, moist conditions and is often found in lawns, pastures, roadsides, gardens, and disturbed areas. It has been used historically as a minor forage plant and in traditional herbal practices, and today it is sometimes valued as a groundcover in temperate gardens due to its tolerance of mowing and foot traffic.

While common mouse-ear chickweed is not typically aggressive, it can become a nuisance weed in lawns, gardens, and agricultural settings. It spreads readily by seed and creeping stems, allowing it to form dense mats that compete with turf, crops, and low-growing native plants. In Hawaiʻi and other sensitive ecosystems, its ability to establish in disturbed or managed areas means it should be monitored and managed to prevent further spread, particularly where it may displace native vegetation or interfere with restoration efforts.

High Risk Traits:

• Elevation range exceeds 3000+ m, demonstrating environmental versatility
  
• Naturalized and able to grow in tropical climates
  
• Widely naturalized, including all main Hawaiian Islands
  
• A weed of lawns, roadsides, pastures, open woodlands and wastelands
  
• Other Cerastium species have become weeds
  
• Tolerates many soil types
  
• Reproduces by seed and by creeping stems that root from the stem joints
  
• Hybridizes with other Cerastium species
  
• Capable of self-pollination
  
• Able to reach maturity in one growing season
  
• Seeds dispersed by wind, as a produce contaminant, and both externally and internally by birds and other animals
  
• Prolific seed production
  
• Seeds may form a persistent seed bank

Low Risk Traits:

• Despite widespread naturalization and reports of weediness, impacts are generally unspecified or not considered to be significant in natural communities
  
• Unarmed (no spines, thorns or burrs)
  
• Palatable to browsing and grazing animals
  
• Non-toxic
  
• Effectively controlled by herbicides
  
• Effectively controlled by hand-pulling and cultivation