The life span of an individual plant depends upon two factors. The first is the innate, genetically determined potential for longevity. The second is the effects of the environment, including soil and weather conditions, competing plants, disease-causing microbes, and herbivores.
Historically, people have classified the life spans of plants into three categories: annuals, biennials, and perennials. Annual plants live for up to one year. Biennials live for approximately two years. Perennials live for more than two years, often for several decades, even centuries.
While this categorization is useful in many ways, botanists have come to recognize that it is inaccurate, especially for plants that grow under natural conditions. Plant life histories are now classified mainly according to the number of times that each individual normally reproduces before it dies. Two main categories are recognized using this system: monocarpic plants and polycarpic plants. Monocarp plants reproduce once before they die. Polycarpic plants reproduce several or many times before they die. Some botanists have defined a third group, the paucicarpic plants that are intermediate between the two. Paucicarpic plants reproduce up to five times.
See also:Monocarpic Plants, Polycarpic and Paucicarpic Plants, Potential and Real Life Spans
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