Assertion: oak's leaf | /r/HasProperty | tough
Facets:
Source sentences:
text: The leaves are tough and leathery, 2 to 5 inches in length, oval in appearance and dark green in color.
text: The blue-green leaves are tough and leathery, deciduous, 4–10 cm (1.6–3.9 in) long, and entire or shallowly lobed.