The tree is 10 meters tall, and will grow at a rate of five meters per round if not hindered in some way. You can safely assume that everyone is more or less healed up and ready to do shit. Kari's attempt to arrow Lenier away failed mainly because Lenier's Cowl was just a collection of bandages bound around his body. There was no loose cloth. Probably could have done better by smacking him with a tree instead. There is no noticeable increase in miasma 'production' from the tree. Compared to its size, the miasma it generates is looking fairly small.