Flower:

Flowers are in a round cluster, about ¾ inches across, in a ring around a purple cone that elongates up to ¾ inch in fruit. Individual flowers are less than ¼ inch across, tubular with 4 irregular lobes, the lower lobe larger than the upper. Color ranges from white to pink to lavender; the center of each flower is usually darker than the outer petals, with 2 pair of yellow-tipped stamens and sometimes a yellow spot in the throat. The flower head sits at the end of a long stalk that arises from the leaf axils in the upper plant.

Leaves and stem:

Leaves are thin, up to 1½ inches long and ½ inch wide, hairless, serrated around the edges, lance-oblong to egg-shaped with a pointed tip, on a short stalk. Attachment is opposite. The stem is square and hairless, erect to ascending, rooting at the nodes and forming colonies.

Fruit:

Fruit is a round, 2-celled capsule with a pair of nutlets in each cell.

Notes:

Often found in areas prone to seasonal flooding, Lance-leaf Fog Fruit doesn't really resemble anything else so is pretty easy to identify.