Saururus cernuus L.

Probably from Stephen Elliott's herbarium.
According to J. Ewan (Classica Botanica
Americana, vol. 6, page xi, X971),
"Elliott’s own collections usually are
labelled in his handwriting simply with
the locality, rarely with a date, and
without any indication that it is his
own specimen. Those plants collected by
others carry the collector's name."
03884623