Broccoli, in the form recognized today, is not a natural vegetable but a result of human intervention. It is a man-made cultivar, meaning its current size, appearance, and flavor were intentionally developed by farmers over centuries. Selective breeding involves choosing desirable traits and propagating them across generations of plants to create a new, distinct variety.
The Wild Ancestor
The original, uncultivated starting point for broccoli is a species called Brassica oleracea, commonly known as wild cabbage or wild mustard. This plant is native to the coastal regions of Europe, thriving particularly on limestone cliffs and rocky shores around the Mediterranean. The wild form does not produce the dense, compact head that we associate with store-bought broccoli.
Instead, the wild cabbage is a loose, leafy, and somewhat weedy biennial plant with thick stems and large, simple leaves. It is generally taller, with small, yellowish flowers that develop rapidly into seed pods. The leaves and stems of the wild plant are edible but often possess a more bitter taste than its modern descendants.
How Broccoli Was Created
The development of broccoli began in the northern Mediterranean region, likely starting around the sixth century BCE. Ancient farmers in the area, particularly those associated with the Roman Empire and the Etruscans, began artificial selection. They focused on plants that showed a tendency to produce larger, less developed flower clusters and thicker, more tender stems.
The goal was to prevent the plant from fully flowering and instead encourage the formation of a large, tight cluster of immature flower buds. This selection process, carried out over many generations, slowly transformed the wild plant into the primitive forms of broccoli. The name itself, derived from the Italian word broccolo, means “the flowering crest of a cabbage.” The modern and most common type, Calabrese broccoli, is named after the Calabria region of Italy, where its cultivation was refined.
The Diverse Family of Cultivated Cabbages
The single species, Brassica oleracea, is the common ancestor of numerous distinct vegetables. The vast differences in appearance across these vegetables are the result of farmers selecting for different parts of the same plant. This agricultural manipulation turned the humble wild cabbage into a diverse family of “cole crops.”
Farmers selected for specific plant parts to create different vegetables:
Kale and collard greens were created by selecting for large, tender leaves.
Cabbage was developed by focusing on the central, terminal leaf bud and selecting for compactness.
Brussels sprouts were formed by selecting for large, tight lateral buds that grow along the main stem.
Broccoli (immature flower buds) and cauliflower (undeveloped, dense flower stalk tissue called the curd) were developed by targeting the flower head, or inflorescence.