Breathing knee
Breath knees , knee roots, or air knees are formed by some swamp and mangrove trees . They break through the soil surface as root loops or negative-gravitropic (growing in the opposite direction of gravity) of the horizontally oriented, near-surface underground root system. Breathing knees serve as pneumatophores ; their aerenchyma (ventilation tissue) ensures the gas exchange of the underground root system in the low-oxygen sediment.
Taxa with breathing knees:
- Bald cypress , Chinese cypress , Bald cypress : cypress family
- Bruguiera , Ceriops : Rhizophore family
- Xylocarpus : mahogany plants
literature
- Philip B. Tomlinson: The Botany of Mangroves. Cambridge University Press, Cambridge et al. 1986, ISBN 0-521-25567-8 (English).
- Christopher H. Briand. " Cypress Knees: To Enduring Enigma ." Arnoldia. 2000-2001, Vol. 60 (4). p. 19-20, 21-25. An extensive review of the published literature concerning cypress knees (English).
- Andreas Roloff, Horst Weisgerber, Ulla Lang, Bernd Stimm (eds.): Trees of North America . From alligator juniper to sugar maple. All characteristic species in portrait. 1st edition. Wiley-VCH Verlag, Weinheim 2010, ISBN 978-3-527-32826-0 , pp. 482–483 ( limited preview in Google Book search).
Web links
Commons : Breath Knee - Collection of images, videos and audio files