Assertion: buckwheat's seed | /r/HasProperty | smooth
Facets:
value: to black
type: OTHER
Source sentences:
text: The mature seed inside is smooth, shiny, and dark brown to black.
text: The seed of buckwheat is a three-sided achene that is smooth, shining, and 5 mm long (Munz, 1973).
text: Seed or fruit of the plant are three sided, and smooth.