Catsear (false dandelion)

Catsear, often called false dandelion or flatweed, forms a flattened basal rosette of leaves pressed close to the soil surface. The leaves are coarsely lobed or toothed, dark green, and conspicuously rough-hairy on both surfaces, which is the single most reliable trait separating it from true dandelion (whose leaves are hairless and a lighter green). Flowering stalks rise above the rosette and are wiry, solid, and branched, each branch bearing one bright-yellow, dandelion-like flower head, whereas a true dandelion has a single hollow, unbranched, leafless stalk topped by one flower. The plant arises from a fleshy, persistent taproot. Mature seed heads form a puffball of parachuted seeds much like a dandelion, but the branched flowering stems and hairy leaves clinch the identification.

Catsear breaks up the uniformity of a lawn with flattened rosettes that smother and shade out surrounding turfgrass, leaving coarse, dark-green leafy patches and tall yellow flower stalks that protrude above a freshly mown surface. The prostrate rosettes create dead or thin spots when removed, and heavy infestations convert a fine, dense stand into a patchy mix dominated by weed rosettes and seed-head stalks.

Catsear is a perennial that reproduces by seed and regenerates from a deep fleshy taproot and crown year after year. Plants build a persistent rosette in their first season and flower from late spring through fall, releasing large numbers of wind-dispersed seeds. Unlike some taprooted perennials, catsear will not resprout from severed root fragments once they are detached from the crown, but the intact crown and taproot allow it to overwinter and re-emerge. Seedlings establish readily in open, disturbed ground and from the persistent rosette the plant returns reliably in subsequent years.

Catsear thrives in low-maintenance, thin, and stressed turf, and it is especially common on infertile, dry, sandy, or compacted soils where the desirable stand is weak. Because the rosette hugs the ground beneath mower height, it tolerates close and infrequent mowing alike and persists where turf density is poor. It invades lawns, roadsides, pastures, and neglected areas, exploiting bare ground and gaps in the canopy; full sun and low competition favor establishment, and once a flowering rosette sets seed it can colonize surrounding open turf.