Sleeper Trees are small fruit-bearing trees found in End Wood of the Forests of Silence, that grow wherever there is a source of shallow, still water. They have slender trunks, and grow fruit shaped like fat pears with golden skin flushed with pink. When the fruit of a Sleeper Tree is eaten, the victim falls into a deep sleep, and the only way to wake them is to feed them the bitter tasting skin. However, both Filli and Kree were able to eat the fruit without falling asleep.
Lief, Barda, and Jasmine found a grove of Sleeper Trees on their way through End Wood. Jasmine said that Sleeper Trees keep to themselves, and only talk amongst each other. They ate the fruit of the trees, which placed them in a deep sleep. The resident Orchard Keeper nearly killed them, but Lindal of Broome drove it off.
Sleeper Trees are cultivated and tended to by Orchard Keepers, who grow the trees in groves to entice travellers. Once they eat the tree's fruit, they fall into a deep sleep. This allows the Orchard Keeper to feast, and the trees to spread.