What is a perennial?
Put simply, a perennial is a plant that has a life cycle of several years. According to EtymologyOnline.com, is is derived from Latin: perennis “lasting through the year (or years).”
This is as opposed to an annual, which has a life cycle of one year. Stated with slightly more detail on Wikipedia.org, “an annual plant is a plant that completes its life cycle, from germination to the production of seed, within one year, and then dies.”