

For annual plants, yearly senescence can be explained as a way of increasing the number of progeny surviving to reproductive age and/or a way of increasing the amount of turnover and thus the rate of evolution. Higher numbers of viable progeny are produced by a redistribution of nutrients from the plant to the seed during senescence and several less important reasons. Some plants have evolved into annuals which die off at the end of each season and leave seeds for the next, whereas closely related plants in the same family have evolved to live as perennials.
