Thanos' Better Aquatic Grass

From OurFoodChain

Despite its name, Thanos' Better Aquatic Grass is just a lowly aquatic plant. Descended from Thanos' Aquatic Grass, it is identical to its ancestor except for one key internal feature--aerenchyma, a spongy tissue that helps transport air it respires through the rest of the polyph, which is located in its leaves and their respective stems, a feature which allows it to easily outgrow its ancestor thanks to the increased efficiency of its respiration. It resides in the shallow waters of Zone 17 wherever the water level generally stays below 2 feet, and it can grow up to 2 feet tall. Despite its aquatic affinity, it mostly relies on air to respire; as a result, it cannot thrive while fully submerged, hence its height. As it has a constant supply of water, its roots are short and its tiny trunk only remains to support its leaves. When water levels drop below its roots or rises above the tops of its leaves, it will stop growing to preserve energy; otherwise, it takes just 2 weeks to mature from a seed. As it lives in water, its seeds--which are black and just heavy enough to not float--are distributed by water currents and they sprout when the water level is high enough that the ground is wet but low enough that they are not submerged, usually during the dry season.