What is "ringent"

Ringent \Rin"gent\, a. [L. ringens, -entis, p. pr. of ringi to open wide the mouth: cf. F. ringent.] (Bot.) Having the lips widely separated and gaping like an open mouth; as a ringent bilabiate corolla.

a. Having the semblance of lips parted wide, such as may be observed in certain flowers.