Assertion: xylem's cell wall | /r/HasProperty | lignin
Facets:
value: typically
type: DEGREE
Source sentences:
text: Some (but not all) plant cells also have a secondary cell wall, typically composed of lignin (the substance that is the primary component of wood).
text: Schlerenchyma cells have secondary cell walls composed of lignin, a tough substance that is the primary component of wood.