Classification of Raunkier

The classification of Raunkier ( standard biological , system of Raunkier is a Classification created in 1934 by the Botaniste Danish Christen Raunkiær in order to organize all the vegetable according to the positioning of the bodies of survival (Méristème S of growth) of the plant during the unfavourable period. One counts 2 categories, divided into classes:

Long-lived or perennial

Persistence of part of the vegetative apparatus during the bad season:

  • Phanérophyte S (of the Greek phaneros : apparent; phuton : plant): buds air door frames with more than 50 cm of the surface of the ground. Plant facing the winter by exposing to its rigors of the Tige S carrying Bourgeon S (e.g. the pine, the beech, the apricot tree, the hazel tree)

  • Chamaephyte S (of the Greek khamai : with ground; phuton : plant): buds air door frames with less than 50 cm of the surface of the ground. One distinguishes the frutescent chamaephytes (buissonnants, more or less drawn up) and the herbaceous chamaephytes (much closer to the ground) (e.g. the myrtiller).
  • Hémicryptophyte S (of the Greek hemi : with half; kryptos : hidden; phuton : plant): buds door frames on the surface of the ground. With the " beautiful saison" , a hémicryptophyte develops a tuft of growths if it is cespiteux, a rivet washer of sheets, more or less prostrate if it is with rivet washers, a set up stem which takes support on varied supports if it is climbing (e.g. the daisy is a hémicryptophyte with rivet washer).
  • Géophyte S (of the Greek Ge : ground, phuton : plant) or Cryptophyte S : buds door frames under the surface of the ground (to distinguish according to nature from the underground body of conservation: géophyte with bulb, tuber, rhizome) (e.g. Crocus sativus).
  • Hydrophyte S : buds door frames under water, immersed sheets.
  • Hélophyte S (of the Greek halations : salt, phuton : plant): buds door frames under water, emerged sheets at least partly. Plants able to thrive in brackish mediums and fresh water. (seaside, estuaries, chotts, marsh, river). (e.g. salicornes, spartine).

Annual

Passage de la bad season in the form of seed:

  • Thérophyte S (of the Greek theros : season, phuton : plant): one indicates by this term a plant which " boucle" its life cycle in a few months (generally between spring and the autumn in moderate climates) and of which do not remain, at the entry of the winter, which the Graine S which will form of new individuals the following year of annual plant (e.g. annual reprimand, Pasteur purse).

Internal bonds

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