Plant Profile: Lactuca

Various species of wild lettuce (Lactuca spp., belonging to the Asteraceae family) are frequently found in nurseries and landscapes, closely resembling sowthistle (Sonchus spp.). These plants typically act as winter annuals but can also sprout in the spring or summer, particularly in irrigated nursery settings. The seedlings develop a rosette of glossy leaves, which feature lobed margins that can vary in shape. While the leaves of wild lettuce bear a resemblance to those of sowthistle, they are distinct in that they do not have prickles along the edges. In warmer conditions, these plants can grow to heights of 3 to 4 feet, although some species may reach up to 8 feet. The flowers are a pale yellow and appear in branched clusters. The seedheads resemble those of dandelions but are smaller in size. Each seed is equipped with a pappus that facilitates dispersal by wind and water. It is advisable to prevent these plants from seeding and to consider using a preemergence broadleaf herbicide that is approved for application.