Hi GeeWilks, Long time no see. My folks had a lot of these not exactly but close and several types. When they don't have enough water they can dry and come back. If not enough sun they can get too much water but those don't look that way. It wasn't a life cycle thing they can go on forever.
What's your though on it. Do you think you over watered or under? There are some very like those growing up here in the mountains over 6000 feet, when it gets dry in the summer they dry down to nothing, I brought some dry things down after a walk and planted them and they came back in no time. Could something have been spilled where they are growing? Do you have an animal that might taint the soil they're in?