Allometric relationships between leaf and petiole traits across 31 floating-leaved plants reveal a different adaptation pattern from terrestrial plants.

We speculated that for floating-leaved plants, the hyperallometric relationship (slope > 1) between the construction of leaf/stoma and petiole was promoted by the high demand for photosynthesis thus more leaves/stomata. While the hypoallometric relationship (slope < 1) between the stomatal and xylem area was related more to the hydraulic process, the selection pressure on stomata was lower than xylem of floating-leaved plants. Allometric relationships among the hydraulic traits on water transport of aquatic plants is the result of natural selection to achieve the maximum carbon gain, which is similar to terrestrial plants.