Pilosella officinarum
mouse-eared hawkweed
Overview
Pilosella officinarum is a low, mat-forming perennial in the aster family that spreads by leafy runners and shallow rhizomes to form dense patches. The basal leaves are 0.5-5 inches (1.5-12 cm) long, lance-shaped, green and bristly above with a felted white-hairy underside, arranged in flat rosettes. From late spring through summer, leafless stalks 2-12 inches (5-30 cm) tall each carry a single lemon-yellow flower head 0.75-1 inch (2-2.5 cm) across, the outer florets often striped red beneath. The plant spreads quickly by runners that root at their tips, forming colonies that crowd out lawn grasses and low plants. It also releases compounds that slow nearby plant growth. Plants grow in poor, dry, acidic soils in lawns, pastures, banks, and disturbed open ground. Native to Europe and Asia, it has naturalized as an invasive weed in North America, New Zealand, and elsewhere. The flowers close in dull weather and at night. Each plant is shallow-rooted, but the dense mats are persistent.
Native Range
Pilosella officinarum is native to Europe and temperate Asia. It has naturalized widely in North America, New Zealand, Australia, and South America, where it is often an invasive weed of pasture and turf. It grows on dry, acidic, low-fertility soils in grassland, lawns, and disturbed ground.Suggested Uses
Occasionally grown as a tough groundcover in dry, infertile sites and gravel, where its spreading mats hold thin soil. In most regions it is managed as a lawn and pasture weed rather than cultivated. Small bees and hoverflies visit the flowers.How to Identify
Appearance
Size & Dimensions
Height2" - 1'
Width/Spread1' - 2'
Reaches mature size in approximately 2 years
Bloom Information
Detailed Descriptions
Foliage Description
green with white-hairy undersideGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight