Hi, 

It is really difficult to tell. Helenium flexuosum and H. autumnale have larger leaves than the narrow-leaf species, H. amarum, which is native more to the southern Midwest. ( Three species are recorded in Maryland.)

Do you know which species you have? Sometimes leaves can grow larger given the microenvironment that the plant is growing in. It's possible that a weed seed could have germinated in the crown of the Sneezeweed. You could try to gently pull it apart at the soil surface and see if it looks like it has a different root system. Otherwise, you could wait to see if it blooms again this year, or until next year if you are going to overwinter it in the container. 

If you are going to keep it in the container, you will want to find a sheltered location, maybe up against the side of your house in full sun and where it will still receive some rainwater, or you can water periodically. You could also partially bury the pot in the ground or surround it with leaves or bags of potting mix or mulch to help insulate the roots. 

Emily

• Purple-headed Sneezeweed -- Illinois Wildflowers
• Helenium flexuosum -- Native Plant Trust
• Helenium flexuosum -- Mt Cuba Center (the last of the five slideshow images shows a clump of foliage before flower stalks have emerged)