Question, grass on Jordan mudflats

["Travis, Ginger" <Ginger@athena.dev.unc.edu>]

C-birders, a colleague of mine at work just asked a brilliant question
(after I told her about all the great shorebirds being seen on the Jordan
Lake mudflats). She drives up Hwy. 751 over Jordan every day and wants to
know how the luxuriant stand of grass in the Northeast Creek cove comes to
be there. In her words, "It looks like someone seeded that place with a
broadcaster." I see the same thing on the Morgan Creek flats as University
Lake recedes. It's a meadow (and geese love it). So here's the question:
is this stuff perennial grass with roots already in the mud, even though the
flats are covered with water most of the year? Is this annual grass? Does
the seed float in on the water every year in some uniform distribution and
then get deposited on the mud when waters recede? Is the seed already in the
mud from previous years and able to survive inundation for months or even
years before the waters go down and the seeds sprout? Does anyone even know
what species of grass it is? And is this grass of any use to dabbling ducks
after the waters come back up in winter? It's not aquatic, but it's
underwater after the lake refills. Inquiring minds want to know!
Ginger Travis
Chapel Hill, N.C.