Celery is not a hybrid, but a domesticated plant intensely cultivated by humans over centuries. All forms of celery, including the familiar stalk vegetable and the bulbous celeriac, belong to the single species Apium graveolens. The confusion arises because the wild ancestor looks and tastes dramatically different from the mild, crisp celery found in modern grocery stores. This extreme transformation is a testament to selective breeding, not a cross between two different species.
Defining Botanical Terms
Understanding the origin of celery requires distinguishing between key botanical concepts. A hybrid is the result of cross-pollinating two different species or genera to create a new, genetically mixed organism. A classic example is the mule, the sterile offspring of a horse and a donkey.
A cultivar, short for “cultivated variety,” is a group of plants within a single species selected and maintained by humans for specific characteristics. Cultivars are propagated to retain desirable traits, such as color or disease resistance. The process by which these traits are enhanced is called domestication or artificial selection. This involves human intervention to intentionally breed successive generations of plants to improve characteristics like size, flavor, or yield.
The Ancestry of Modern Celery
All modern varieties of celery trace their lineage back to the wild species Apium graveolens. This original plant, historically known as “smallage” or marsh parsley, is native to the Mediterranean region, including Europe, North Africa, and the Middle East.
Wild celery is an erect biennial or perennial herb that grows in moist, often saline areas. Unlike the smooth, pale stalks of grocery store celery, the wild form is characterized by slender, hollow, and fibrous petioles. It possesses an intensely strong, bitter flavor due to a high concentration of aromatic compounds. Ancient civilizations, including the Egyptians and Greeks, used smallage primarily for medicinal purposes, ritual, and as a flavoring agent, not as a main vegetable.
Domestication vs. Hybridization
The dramatic difference between the wild plant and the cultivated vegetable results from thousands of years of domestication, not hybridization between species. The first phase of cultivation, likely beginning in the Mediterranean, focused on using the plant medicinally. By the 16th or 17th century, selection shifted toward improving it as a food source.
Plant breeders focused on two primary goals: reducing bitterness and increasing the size and succulence of the edible parts. The intense, pungent flavor of wild celery is primarily due to chemical compounds known as terpenoids. Humans selectively bred plants with naturally lower levels of these compounds, leading to the development of different cultivar groups, all within the species Apium graveolens.
Stalk celery (Apium graveolens var. dulce or Dulce Group), the most common grocery item, was developed by selecting plants with thick, solid, and juicy leaf stalks (petioles). Another well-known cultivar, celeriac (Apium graveolens var. rapaceum), was created by enlarging the hypocotyl (the area between the stem and the root) into a large, edible bulb. These distinct forms—stalk celery, celeriac, and leaf celery—are different branches of the same species, proving celery is a product of agricultural selection rather than a cross-species hybrid.