The crisp, leafy vegetable known as lettuce, or Lactuca sativa, has a history that stretches back millennia. This common salad ingredient originated in the broader Mediterranean Basin and the Near East, not the Americas or Europe. The journey of lettuce from a prickly, bitter weed to a leafy staple began in the cradle of ancient civilization.
The Wild Ancestor
The modern cultivated lettuce traces its lineage directly to a wild species called Lactuca serriola, commonly known as prickly lettuce or compass plant. This ancestor is an annual or biennial plant native across the Mediterranean, Western Asia, and much of Europe. It thrives in disturbed habitats like roadsides and fields, demonstrating a natural hardiness harnessed by early farmers.
The physical characteristics of Lactuca serriola include oblong or lanceolate leaves, often deeply lobed, and covered with fine spines along the margins and the midrib. The plant grows tall, sometimes reaching two meters, with a rigid, upright habit. The sap released from the stem and leaves is milky, a characteristic that gives the genus its name, Lactuca, from the Latin word for milk, lac. This sap also contains compounds that give the wild leaves a bitter taste.
Early Domestication and Ancient Use
Domestication began approximately 4,000 to 6,000 years ago, with evidence pointing toward the Caucasus region and ancient Egypt. Initially, the plant was cultivated not for its leaves but for its seeds, which were pressed to extract edible oil. Selective breeding focused on eliminating the seed-shattering trait to make harvesting more efficient.
The ancient Egyptians were instrumental in shifting lettuce from an oilseed crop to a leaf vegetable, with depictions appearing in tombs as early as 2680 BC. They began the selective process that reduced the bitterness and spiny nature of the leaves. The tall, upright varieties they developed resembled the modern Romaine type. These early, non-heading forms were also associated with the god of fertility, Min, due to the milky sap’s symbolic properties.
The cultivated plant then spread to the Greeks and Romans, who further refined it as a leaf vegetable staple. The Romans cultivated several varieties and gave the plant its genus name, lactuca. They commonly served the leaves, sometimes cooked, at the end of a meal. Continuous selection by various Mediterranean cultures led to a significant increase in leaf size and a reduction in bitterness.
Global Dissemination and Modern Forms
Following its establishment in the Mediterranean, lettuce traveled across Europe during the Middle Ages, becoming a common garden vegetable. The Romans likely introduced the plant to Northern Europe, where selective breeding continued.
By the 15th and 16th centuries, European farmers had developed diverse forms, including the soft-leaved Butterhead and the early ancestors of Crisphead varieties. The plant was introduced to the Americas by European settlers, possibly as early as Christopher Columbus’s second voyage in 1494. This new environment fostered further diversification, particularly with the development of the durable Crisphead type, like Iceberg lettuce, which was bred in the United States for easier shipping and longer shelf life.
Today, continuous selective breeding has resulted in four major cultivar groups: Crisphead, Butterhead, Looseleaf, and Romaine (also known as Cos). Each group represents a distinct morphological adaptation developed in different regions and climates, linking the ancient, upright, bitter plant of the Near East to the vast array of mild, leafy greens consumed worldwide.