mystery plant

[Linda Lee]

Colleagues:

Do you know this plant?  I have been unable to ID it.
Photo at http://cricket.biol.sc.edu/acmoore/herb.jpg


Description: leaves alternate (could possibly key as opposite) with glandular
trichomes, tacky to the touch, and gathering sand when collected for
pressing.  Flowers solitary, axillary, 5-merous; corollas sympetalous, purple
distally but whitish on the tube.  Calyx lobes more than 2x length of the cup,
apices rounded.  Capsule with 2 sutures, 1 locule, containing many light
brown, pitted seeds.  The ruptured capsule looks like a pope's hat (miter),
nestled within the still-green calyx.  Calyx 2x length of mature capsule.  Low
but not creeping, < 2 dm.  From SE US, outer coastal plain.

Thanks,

Linda