Assertion: meristem's cell | /r/MadeOf | lignin
Facets:
Source sentences:
text: The cells of the secondary xylem contain lignin, the primary component of wood, which provides hardiness and strength.
text: The cells of the secondary xylem contain lignin, which provides hardiness and strength.
text: The cells of the secondary xylem contain lignin, which provides hardiness and strength.