Cycadophytina
Cycadophytina, Fiederblättrige Nacktsamer, ca. 200 Arten umfassende Unterabteilung der Spermatophyta; bildet zusammen mit den Coniferophytina die Entwicklungsstufe der Gymnospermae. Merkmale: große fiedernervige Laubblätter; die Staubblätter (Mikrosporophylle) tragen viele Pollensackgruppen, die Fruchtblätter (Megasporophylle) primär mehrere Samenanlagen. Die C. entwickelten sich parallel zu den Coniferophytina ab dem Oberdevon aus Progymnospermen. Progressionen innerhalb der fossilen Formen zeigen sich u.a. in der Ausbildung von Blüten, der Eustele, eines Perianths, eines zweiten Integuments, des Übergangs zur Zoogamie. Heute existieren nur noch Restgruppen. Die C. werden in zwei ausgestorbene ( Lyginopteridopsida; Bennettitopsida) und zwei rezente Klassen ( Cycadopsida; Gnetopsida) gegliedert.

Deutsch wörterbuch der biologie. 2013.

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  • Cycadophytina — Cycadophyta Cycadophyta, Cycadophytina Cycadophytina, Cycadopsida Cycadopsida . a class or subdivision of plants comprising palmlike gymnosperms: it includes the surviving order {Cycadales} and several extinct orders; possibly not a natural… …   The Collaborative International Dictionary of English

  • Cycadophytina — noun palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) • Syn:… …   Useful english dictionary

  • subdivision Cycadophytina — noun palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) • Syn:… …   Useful english dictionary

  • Cycadophyta — Cycadophyta, Cycadophytina Cycadophytina, Cycadopsida Cycadopsida . a class or subdivision of plants comprising palmlike gymnosperms: it includes the surviving order {Cycadales} and several extinct orders; possibly not a natural group; in some… …   The Collaborative International Dictionary of English

  • Cycadopsida — Cycadophyta Cycadophyta, Cycadophytina Cycadophytina, Cycadopsida Cycadopsida . a class or subdivision of plants comprising palmlike gymnosperms: it includes the surviving order {Cycadales} and several extinct orders; possibly not a natural… …   The Collaborative International Dictionary of English

  • class Cycadopsida — noun palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) • Syn:… …   Useful english dictionary

  • class Gymnospermae — noun plants having naked seeds not enclosed in an ovary; in some systems considered a class (Gymnospermae) and in others a division (Gymnospermophyta); comprises three subdivisions (or classes): Cycadophytina (class Cycadopsida) and Gnetophytina… …   Useful english dictionary

  • Cycadophyta — noun palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) • Syn:… …   Useful english dictionary

  • Cycadopsida — noun palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) • Syn: ↑class… …   Useful english dictionary

  • division Gymnospermophyta — noun plants having naked seeds not enclosed in an ovary; in some systems considered a class (Gymnospermae) and in others a division (Gymnospermophyta); comprises three subdivisions (or classes): Cycadophytina (class Cycadopsida) and Gnetophytina… …   Useful english dictionary

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