Millet is not a single species but a collective term for several small-seeded grasses cultivated worldwide as cereal grains or fodder. These grains, belonging to the Poaceae family, are known for their resilience in hot, dry environments where other grains often fail. Understanding the millet plant’s appearance requires looking beyond its tiny seed to the unique structure of its stalk, leaves, and grain-bearing head.
General Structure and Vegetative Parts
The structure of the millet plant resembles other cultivated grasses, such as corn or sorghum. The plant’s stalk, or culm, is upright and rigid, segmented by noticeable nodes or joints along its length. Depending on the variety, the height of the main culm can range from one foot to ten feet, with the tallest examples being Pearl Millet.
The leaves are long, narrow, and linear, showing the characteristic parallel venation found in grasses. These leaf blades emerge alternately from the nodes and usually wrap around the stem at the base, much like the leaves of maize. Many varieties produce multiple side shoots, known as tillers, from the base of the plant, giving it a bushy or bunched appearance.
The Appearance of the Grain Head
The most distinct feature of any millet plant is its inflorescence, the structure that holds the developing grains. This seed head can take one of two primary forms: a dense, cylindrical spike or an open, branching panicle. The inflorescence forms at the top of the main culm and is responsible for the plant’s final profile.
A compact spike inflorescence appears as a densely packed, elongated cylinder, often described as candle-like in shape. In species like Pearl Millet, this spike can be quite thick, with the tiny seeds tightly clustered along a central axis. Conversely, an open panicle inflorescence is characterized by many loose, spreading branches that emerge from the main stem. This creates an airy, feathery appearance, sometimes causing the panicle to droop slightly due to the weight of the developing seeds. The tiny, rounded millet grains, which range in color from white and yellow to red or brown, develop within these structures.
Visual Differences Among Common Types
Since the term “millet” covers multiple species, their seed heads provide the clearest way to distinguish them visually. Pearl Millet, often the tallest variety, is easily recognized by its thick, elongated, and highly compact spike, which can reach up to one foot in length. This dense structure makes the grain head appear solid and heavy.
Foxtail Millet is named for its distinctive inflorescence, a dense, brush-like spike that often droops slightly, resembling a fox’s tail. This head is more slender than Pearl Millet, with tiny bristles that give it a bristly texture. Proso Millet, also known as Common Millet, presents with a notably open and loose panicle. The seed clusters branch out widely from the main axis, contrasting sharply with the dense spikes of the other common types.