Giant salvinia

Giant salvinia (Salvinia molesta) is a free-floating fern with paired oval leaves, 1–4 cm long, covered in stiff hairs. The diagnostic feature is the egg-beater hairs on mature leaves — the hair tips split into a whisk shape. Distinguishes it from common salvinia, which has unbranched hairs. Doubles in 4–10 days in warm water. The salvinia weevil (Cyrtobagous salviniae) is an effective biological control on Texas and Louisiana lakes. Most states require reporting any sighting.