biennial (redirected from biennium)

biennial, plant requiring two years to complete its life cycle, as distinguished from an annual or a perennial. In the first year a biennial usually produces a rosette of leaves (e.g., the cabbage) and a fleshy root, which acts as a food reserve over the winter. During the second year the plant produces flowers and seeds and, having exhausted its food reserve, then dies. Short-lived perennials (e.g., the hollyhock) are often treated as biennials. Some biennials will, like annuals, bloom in the same season if sown early; others reseed themselves or produce offsets, thus perpetuating the plant indefinitely so that it becomes essentially a perennial. There are very few true biennials. Many are crop plants, such as carrots and parsnips, which are harvested for their succulent roots at the end of their first growing season.

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biennial

Any plant that completes its life cycle in two growing seasons. During the first growing season biennials produce roots, stems, and leaves; during the second they produce flowers, fruits, and seeds, and then die. Sugar beets and carrots are examples of biennials. See also annual, perennial.

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biennial

a plant, such as the carrot, that completes its life cycle within two years, developing vegetative storage parts during the first year and flowering and fruiting in its second year