Assertion: periwinkle's flower | /r/HasProperty | double
Facets:
value: usually
type: DEGREE
Source sentences:
text: Vinca minor ‘Flore Pleno’ is one of the few periwinkles that have double flowers.
text: Lesser periwinkle (Vinca minor) is similar, but has smaller leaves (2-5 x 1-2 cm) and flowers are usually doubles that are half the size of those of V. major.