Cor rotate, with elongate, acute lobes and prominent fornices; filaments prolonged beyond the base of the anther into a prominent dorsal appendage; anthers elongate, conspicuous, connivent around the style; nutlets with a swollen, stipe-like basal attachment that fits into a pit in the otherwise flattish gynobase, the attachment surrounded by a prominent thickened rim (the basal margin of the nutlet) that fits closely to the gynobase; broad-leaved, coarsely hairy herbs with blue fls in loose, terminal modified sympodial cymes, these leafy-bracteate below, the long pedicels recurved in fr. 3, Old World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.