The lemon, Citrus limon, is an ancient hybrid, originally descending from a cross between a male citron (Citrus medica) and a female sour orange (a mix of pomelo and mandarin). Determining a precise number of its “varieties” is impossible because true lemons are not naturally occurring species. The difficulty stems from the lemon’s complex botanical history and its tendency toward spontaneous mutation and hybridization, meaning the count of distinct lemon types is constantly shifting due to cultivation and natural changes.
Defining Cultivars: Why the Number is Fluid
The confusion in counting lemon types often begins with terminology, as the casual word “variety” is botanically imprecise. In science, the term cultivar—a “cultivated variety”—designates a specific plant selected and maintained through propagation, such as grafting, for its desirable traits. The number of cultivars is fluid because the citrus genus is highly prone to natural cross-pollination and hybridization.
New lemon types can also arise from a simple genetic change known as a bud mutation, or “sport.” This occurs when one branch on a tree suddenly produces fruit with different characteristics, such as pink flesh. When growers propagate these unique branches, a new cultivar is created without intentional cross-breeding. This ease of mutation means that hundreds of distinct lemon types exist worldwide, far more than what is commonly seen in commerce.
The Primary Commercial Staples
Global commerce is dominated by only a few major types known for their consistent quality, high yield, and shipping resilience. The two most recognized commercial staples are the Eureka and Lisbon lemons, which together form the bulk of the world’s market supply.
The Eureka lemon is the most common variety found in grocery stores across the United States. It is characterized by its moderately thick, slightly rough rind and an oblong shape often featuring a small nipple at the blossom end. Eureka trees are virtually thornless and produce fruit year-round that is typically low in seeds.
The Lisbon lemon is the other primary commercial staple, known for being hardier and more cold-tolerant than the Eureka. This variety produces fruit with a smoother, thinner rind and a higher juice yield, making it efficient for processing. Lisbon trees are more vigorous and dense, with fruit often protected within the canopy, offering greater resistance to adverse weather.
Specialty and Ornamental Varieties
Beyond the commercial mainstream, the total count of lemon types includes specialty and ornamental cultivars grown for niche markets or home gardens. The Meyer lemon (Citrus × meyeri) is perhaps the most famous, being a natural hybrid of a true lemon and a mandarin orange or pomelo. This parentage gives the Meyer a distinctive, floral aroma, a thinner, smoother rind that often turns orange-yellow when ripe, and a significantly lower acidity level than Eureka or Lisbon lemons.
The Ponderosa lemon (Citrus × pyriformis) is a hybrid of a citron and a lemon that is primarily grown as an ornamental plant. The Ponderosa is notable for its massive fruit, which can weigh up to two pounds and possesses a thick, bumpy rind and a seedy pulp. While its flavor remains intensely tart, its size and low juice yield limit its commercial appeal for juicing.
The Pink Variegated lemon, also called the Pink-Fleshed Eureka, is an example of a bud mutation from the standard Eureka. The fruit is instantly recognizable by its yellow and green striped rind when immature and its internal pink-tinged flesh. Although it maintains the classic, high-acid flavor of a Eureka, its unique variegated leaves and colorful fruit make it prized for decorative value.