Annual, perennial and biennial are related words that are particularly used in gardening terminology. In general, annual describes something that occurs once a year, such as an annual Christmas party, or something that lasts for one year, such as an annual magazine subscription. In gardening terminology, annual describes a plant with a life cycle that takes less than a year to complete, from germination to seed production. Bedding plants that must be replanted each spring are annual plants. Annual may be used as an adjective or a verb, it is derived from the Latin word annualis, meaning yearly.
Perennial describes something that lasts for a long time, something that is enduring or seems perpetual. In gardening terms, a plant that lives for more than two years is considered a perennial. Perennials often die back to the ground in winter and come back with regrowth from its roots in the spring. In some climates, perennials simply go dormant in the winter before putting forth buds in the spring. Perennial may also be used as an adjective or noun, it is derived from the Latin word perennis, which means continual.
Biennial describes something that occurs every two years, such as a biennial convention, or something that lasts for two years, such as a biennial license. When talking about plants, a biennial is a plant which takes two years in order to complete its life cycle from germination to seed production. Examples of biennials are dianthus and onions. Biennial may be used as an adjective or a noun, it is derived from the Latin word biennium, which means a period of two years.
If you go to one party in the Hamptons over the summer, you might as well make it the annual benefit for the Apollo. (The Wall Street Journal)
It is an upright perennial herbaceous plant that reaches up to one metre tall and produces highly branched, yellow to orange, cylindrical, aromatic rhizomes. (The Trinidad and Tobago Guardian)
With artworks in the bathroom, others hidden from public view, performance art and even an exhibition within the exhibition – that’s essentially an artwork – the 2016 TarraWarra Biennial promises an eclectic survey of contemporary Australian art. (The Sydney Morning Herald)