Assertion: mature xylem | /r/HasProperty | metaxylem
Facets:
Source sentences:
text: The side walls have five patterns of thickening, which are believed to represent a developmental sequence from the initial xylem (protoxylem) to the final mature xylem (metaxylem): annular (a series of rings), helical (a long continuous spiral), reticular (a network), scalariform (a series of elongated bordered slits), and circular bordered pitting.