A young plant has a broken stem. Can it be put in water to grow roots, or how can the stem be saved? Please reference picture of bent stem.
If the flowerhead has tiny seeds on it, you can cut it off a few inches above the stem and place it face down in a pot of moist soil and it should grow. I've read that you can do this with or without the seeds present.
The best way to propagate it is by division in spring.
https://www.gardeningknowhow.com/ornamental/foliage/papyrus/papyrus-plants.htm