Definition: Treeless, level, or gently rolling plains characteristic of arctic or subarctic regions, having a permanently frozen subsoil, and usually supporting low growing vegetation such as lichens, mosses, and stunted shrubs.
Definition: Determined for type of life cycle being annual, binneal, perennial etc.
Comment: The life cycle habit indicates the typical duration of an individual plant's life. Common values are annual, biennial, and perennial. Some plants have different durations depending on environment or location, so a plant can have more than one value.
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
Attribution: Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 12, July 2012. Glossary: http://www.mobot.org/mobot/research/apweb/top/glossaryi_p.html#perennial
