In the early 1990s hedge hyssop began appearing in rice fields in the spring. Usually these fields had held water all winter. It is not competitive with the crop, but may interfere with planting.

There are two species of hedge hyssop common in Louisiana rice fields, Gratiola virginiana and G. neglecta. These are G. virginiana.

The flowers of the two species of hedge hyssop are very similar. The one here is of G. virginiana. It is not on a stalk (peduncle) or at least it is very short.

The flower here is of Gratiola neglecta. It closely resembles that of G. virginiana.

The flower of Gratiola neglecta is on a stalk or peduncle while that of G. virginiana is sessile or lacks a stalk.