Assertion: blackberry's root system | /r/HasProperty | perennial
Facets:
Source sentences:
text: Blackberry has perennial root system and are stout, branched, creeping underground, growing vertically to a maximum depth of 1.5 m depending on soil type.
text: Blackberries have a perennial root system and biennial canes.
text: The root system of raspberries and blackberries is perennial, but each shoot is biennial.