Kleistogamy

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Inflorescence of Lamium amplexicaule with several cleistogamic and one chasmogamous flowers.

Kleistogamy ( ancient Greek κλειστός kleistós "closed" and γάμος gámos "wedding", "marriage") is a form of targeted plant self-pollination in closed flowers with the result of direct , spontaneous (obligatory) or indirect (optional) self-fertilization (autogamy).

One can distinguish between:

  • Archicleistogamy (direct, spontaneous autogamy); real, obligatory forced pollination, with reduced pollination organs
  • Archo-, pseudocleistogamy (indirect autogamy); fake, optional forced pollination, with unaltered or hardly changed pollination organs. Self-pollination in the flower that has not opened due to environmental conditions.
    • Photocleistogamy; as a result of lack of light
    • Hydrocleistogamy; by flooding the flower, high water level
    • Psychro-, thermocleistogamy; from lack of warmth
    • Xerocleistogamy; due to severe drought

The opposite, i.e. pollination when the flowers are open, is called chasmogamy . This is the "normal case" and includes both foreign and self-pollination.

Some plant species, for example the violet or the stem-embracing dead nettle and the wood sorrel ( Oxalis acetosella ), have, in addition to the normal, chasmogamous, cross-pollinated flowers, other, kleistogamous flowers that remain small and inconspicuous, do not open and pollinate themselves. This different blooming of pleomorphic flowers, Chasmo-Kleistogamy on one plant is also called allautogamy or amphigamy . A typical example of Kleistogamy are the species of the genus Frailea from the family of the cactus plants .

Since cleistogamous flowers often also develop morphologically modified fruits, in species with both cleistogamous and chasmogamous flowers, seeds are spread to different degrees, which at the same time have different genetic properties.

Individual evidence

  1. Karl Linsbauer (Ed.): Short dictionary of botany. 2nd Edition. Engelmann, 1917, p. 102 f, archive.org .
  2. O. von Kirchner , E. Loew , C. Schröter : Life history of the flowering plants of Central Europe. Volume 1, Section 1, Ulmer, 1908, p. 19 f, glossary, archive.org .
  3. Manfred Eichhorn: German Dictionary of Biology / Dictionary Biologie Englisch. Volume 1, Routledge, 1999, ISBN 0-415-17129-6 .
  4. ^ Paul Knuth : Handbook of flower biology. 1. Volume, Engelmann, 1898, p. 67, archive.org .
  5. ^ R. Rieger, A. Michaelis: Genetic and cytogenetic dictionary. 2nd Edition. Springer, 1958, ISBN 978-3-642-53221-4 , p. 586.
  6. ^ Edward M. Barrows: Animal Behavior Desk Reference. Third Edition, CRC Press, 2011, ISBN 978-1-4398-3651-4 , pp. 217 ff.
  7. O. von Kirchner , E. Loew , C. Schröter : Life history of the flowering plants of Central Europe. Volume 1, Section 1, Ulmer, 1908, p. 19 f, glossary, archive.org .
  8. Walter Durka: Blossom and Reproduction Biology . Series of publications for vegetation science, issue 38, Federal Agency for Nature Conservation, Bonn 2002, pp. 133–175, online ( Memento from July 19, 2011 in the Internet Archive ) (PDF; 532 kB).