Hello poolboy101,

Just replant it and it should grow back any lost parts. The rhizomes are basically just containers that hold extra sugars for the plant during dormancy, like a carrot or potato, so insects will eat on them and they will break off occasionally, so it is nothing to worry tremendously about so long as mold and rot is not evident. Over time, those rhizomes will grow long and thick and more plants will grow from them in a clump. In cultivation, those rhizomes are often cut into one inch sections when the plant is old enough and each will grow into a new plant just like quartering a potato to make a bunch of new potato plants. Just repot it and dont disurb it anymore and it should be fine. If in doubt, you can get some neem oil or sulfur based fungicide, none of the soap based stuff, only water based or dry poweder, and use that on the soil and rhizome to keep infection out while it recovers. If the rhizome section that fell off was brown and dried up, it probably was just a part that the plant was not using anymore, so it just broke off on its own. Healthy rhizome sections will be creamy white with some occasional reddish coloration to them. Outside they might have some bark like brown coating, but inside they should be white and firm like a potato before boiling.