Travels to their village on the back of one of these seed wheeled unicycles and learns their language. The village is threatened by large birds (?) or boats. I vaguely recall she is being pursued by someone from her home world, and something or someone is threatening the trees. Writing style feels very Ursula K. LeGuin. This is so vague, and it's haunting me. I also imagined the local creatures kind of like armadillos; they used part of their bodies to hold onto the wheel to move the unicycle.