spiral thickening

spiral thickening

a deposition of lignin on the inner surface of a XYLEM VESSEL, forming a spiral pattern.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
determine the plant cell wall spiral thickening's direction of twist and apply this information to a botanical identification;
The vessel cell walls had spiral thickenings. Both pool cue and sliver might be maple then, but not birch.