For months I've been watering my citrus trees, and because of proximity, also my neighbor's. Part of his tree overhangs the fence, but since it's fruit, I'm not complaining. I just picked one of the little fruits. It has a thick yellow rind (like a lemon or sweet lime), almost no pulp, and is completely full of seeds. I licked it, and it's very bitter, with a hint of an orange flavor. Does anyone know what it is?