Lisbon is of Portuguese origin, although it is not known there by that name. It is believed to be a selection of the Gallego seedling clonal group, which in Portugal is somewhat comparable to the common sweet orange groups of Spain, Italy, and numerous other countries. A selection known as Portugal in Morocco and Algeria is said to be indistinguishable from the Lisbon introduced from California. The earliest reference to Lisbon in California appears to be its listing in the 1853 catalogue of Warren and Sons Nursery and Garden in Sacramento. It was brought to California in 1849 or soon thereafter from Massachusetts by J. L. L. F. Warren, who had listed it in a nursery catalogue issued at Nonantum Vale, near Boston, as early as 1843 (Butterfield, 1963). It is virtually certain that this variety ultimately reached southern California, for Caryl (1940) reports that budwood from an old Lisbon lemon tree growing in Alameda was shipped to S. P. Stowe of Goleta in 1883. Two importations are known to have been made from Australia, where this variety was introduced as early as 1824 (Bowman, 1955). The first was by S. P. Stowe in 1874, who shared his introduction with Thomas A. Garey, a pioneer citrus nurseryman of Los Angeles. The second was by J. W. North of Riverside, who received a few small trees in 1875 and turned them over to D. N. Burnham, a California nurseryman. The vigor, hardiness, and high productivity of Lisbon combined to establish its early and enduring popularity, particularly in the California interior districts. Eureka has been its only rival, principally in the coastal districts, though in recent decades that variety has declined somewhat in popularity in favor of Lisbon. Although not as widely grown as Eureka in most other lemon-producing countries, Lisbon is unquestionably one of the major varieties. Fruit medium in size, elliptical to oblong; base tapering to inconspicuous neck; apex tapering likewise into a usually large, prominent nipple surrounded by an irregular areolar furrow, commonly deeper on one side. Seed content variable, but usually few to none. Color yellow at maturity. Rind medium-thick; surface finely pitted, faintly rugose, inconspicuously ribbed if at all; tightly adherent. Segments about 10; core small and solid. Flesh color pale greenish-yellow; fine-grained, tender, juicy; flavor very acid. Crop comes mainly in winter and early spring. Tree vigorous, upright-spreading, large, thorny, densely foliated, and productive. Tree most vigorous of varieties grown in California and most resistant to adverse conditions such as frost, heat, wind, and neglect.