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Spirals on a sunflower
Detail of Aeonium tabuliforme showing the multiple spiral arrangement (parastichy)

Parastichy, in phyllotaxy, is the spiral pattern of the areoles on some plants, such as cacti, sunflowers and pine cones.[1] These spirals involve the insertion of a single primordium.[2]

See alsoEdit


  1. ^ Webster's Revised Unabridged Dictionary. C. & G. Merriam Co. 1913.
  2. ^ Weise, Dmitriy (1998-10-29). "Principle of Minimax and Rise Phyllotaxis". Retrieved 2008-12-14.

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