Lactuca — 16 species

Lactuca is a cool-season leafy genus best known for cultivated lettuces — Butterhead, Romaine, Loose-leaf, and others derived mainly from L. sativa. Plants prefer full sun to partial shade, ideally six hours of light daily, with afternoon shade appreciated during warm spells to delay bolting. Keep soil consistently moist; uneven watering leads to tip burn and premature flowering. Optimal growing temperatures sit between 60–68°F (15–20°C). According to the ASPCA, lettuce is non-toxic to cats and dogs, making the entire genus pet-safe.