This is Senna marilandica, also known as Maryland senna, Maryland wild senna, Southern wild senna, and simply Wild senna. This plant is almost identical to Senna herbecarpa, but the Maryland senna has pods which stay closed much longer. It is good to have both senna because Senna herbecarpa will feed the birds early in the year, and this Maryland Senna will feed the animals long after the others are gone. This plant is the larval host plant for the Cloudless Sulphur, Orange-Barred Sulphur, Tailed Orange, Little Yellow, and Sleepy Orange butterflies. USDA Hardiness Zones 5 to 8.