Help with ID of Cardaria?

[Monique Reed]

Taxacomers,

I am working my way through some specimens from New England and have run across a member of the Brassicaceae that causes some problems.  It keys in several sources to _Cardaria pubescens_ and seems to match images online, but no source I have lists it for Massachusetts, and the plant was much taller (1.4 m) than _C. pubescens_  is said to be.  I'm unfamiliar with the species and could use some help with either a confirmation or alternative identification.

A brief description:  plant with one stem from the base, branched above; upper leaves tapered to the base, entire or with a few small teeth.  Inflorescence with multiple branches, not flat-topped; flowers ca. 2 mm across; sepals ovate to orbicular, with thin white margins, with short, sparee, rather crinkly hairs on the lower portion; petals equal, white, clawed, longer than the sepals.  Fruits at this stage very immature, ellipsoid to ovoid, plump or flattened perpendicular to the replum, seeds one in each locule, style short, stigma capitate.  The plants are from a coastal salt marsh protected from open sea by islands.  Collected early July in Norfolk Co., Massachusetts. 

I can e-mail or put up a scan if it would help

Any suggestions gratefully welcome!

Monique Reed
Biology Department Herbarium
Texas A&MUniversity
College Station, TX 77843-3258