Assertion: comfrey's cultivar | /r/HasProperty | unable spread
Facets:
value: by seed
type: MANNER
Source sentences:
text: The “Bocking 14” cultivar of Russian Comfrey (Symphytum x uplandicum) has gained popularity in recent years, as this strain of the plant is sterile, and is thus unable spread by seed, vastly reducing the risk for this comfrey to spread out of control once planted.