ROOTS GROWING IN ROCK FISSURES - THEIR MORPHOLOGICAL ADAPTATION

摘要

On sites with shallow soil in semi-arid climate conditions, whiteleaf manzanita (Arctostaphyllos viscida) and Pacific madrone (Arbutus menziesii) utilize water from the bedrock. Roots of these plants occupy rock fissures as small as 100 mu m. Although the root stele remains cylindrical in shape without visible mechanical stress, the cortex may become flat, creating ''wing-like'' structures on the sides of the stele. Fine particles of soil and rock that fill the space between root cortex and rock matrices create good contact for water flow.