Eureka lemon trees (Citrus limon ‘Eureka’) are medium-sized, nearly thornless citrus trees that bear oblong to elliptical lemons. The lemons are acidic, juicy, ridged lengthwise and slightly rough with oil glands on the peel. Eureka lemon trees originated from an Italian lemon tree seed and bud wood from a propagated variety. These lemon trees are extremely cold-sensitive and can grow only in the warmest climates. In the appropriate environment, Eureka lemon trees produce large clusters of fruits year-round, and are especially abundant during late winter, spring and early summer.