BioConcepts

therophytethérophyte (fr.); Therophyt (ger.)

• A plant life form in Raunkiaer's system of classification. Therophytes are annual plants that complete their life cycle in a short period when conditions are favourable and survive harsh conditions as seeds. They are typically found in deserts and other arid regions. (Oxford Dict. of Biology 2008)
  category life form

  1904

  V. Enaarige, Sommerplanter eller den gunstige Aarstids Planter, Therofyter.

  Raunkiær, C. (1904). Om biologiske Typer, med Hensyn til Planternes Tilpasning til at overleve ugunstige Aarstider. Botanisk Tidskrift 26, XIV.

  1905

  Il nous reste à mentionner un cinquième type principal, celui des plantes annuelles ou plantes de la bonne saison (Thérophytes), dont le développement s’accomplit en une seule saison favourable, et qui ne passent la mauvaise saison qu’à l’état de graine.

  Raunkiær, C. (1905). Types biologiques pour la géographie botanique. Oversigt over Det Kongelige Danske Videnskabernes Selskabs Forhandlinger, 1905, 347-438: 354; transl. in id. (1934). The Life Forms of Plants and Statistical Plant Geography.

  1907

  Hence he [scil. Raunkiaer] proposes a new classification, based on resting buds and other organs that are most in evidence in rigorous seasons. On this basis five great plant classes are recognized: phanerophytes, whose buds are considerably above the ground (trees and shrubs); chamephytes, whose buds are slightly above the ground; hemicryptophytes, whose buds are at the ground level; cryptophytes, whose buds are hidden in the ground; and therophytes, whose buds persist only in seeds (annuals).

  Cowles, H.C. (1907). Resting buds as indices of ecological types. Botanical Gazette 44, 392.

  1909

  His [scil. Raunkiær’s] five chief groups were phanerophytes, chamaephytes, hemicryptophytes, cryptophytes, and therophytes.

  Warming, E. (1909). Oecology of Plants: 5.

  1910

  V. Therophyten (θέρος = Sommer); einjährige Pflanzen; die ungünstige Jahreszeit betrifft nur die durch ihre Schale geschützten Samen.

  Tobler, G. (transl.) (1910). In: Raunkiaer, C. (1910). Statistik der Lebensformen als Grundlage für die biologische Pflanzengeographie. Beiheft zum Bot. Centralbl. 27 (2), 171-206: 171.

  1913

  Therophytes, or plants of the favourable season, live through the unfavourable season as seeds; hence they are annual plants.

  Smith, W.G. (1913). Raunkiaer’s “life-forms” and statistical methods. Journal of Ecology 1, 16-26: 18.

  1982

  therophyte An annual plant; a plant that completes its life cycle in a single season, passing unfavourable seasons as a seed; cf. Raunkiaerian life forms.

  Lincoln, R.J., Boxshall, G.A. & Clark, P.F. (1982). A Dictionary of Ecology, Evolution and Systematics: 247.