Assertion: birch's bark | /r/HasProperty | variable
Facets:
value: depending upon the type of birch
type: OTHER
value: on this species
type: OTHER
Source sentences:
text: The thin bark is variable on this species and may be very white or more brownish in color..
text: Depending upon the type of birch, the bark can be white, silver or variations of both, developing dark gray to black markings or horizontal streaks of gray as the tree ages; the bark on older trees is much darker than on young trees.