Tesseleaves
Tesseleaves replaced their ancestor. Being dependent on sunlight and therefore not having the energy to maintain them, these tiny freshwater leaves completely lack muscles, though they retain a simple nervous system. The feature which caused them to replace their ancestor is sexual reproduction, accomplished with short modified hairs on the underside of the leaves which produce waterborne spores. The longer hairs used for tangling with neighbors are concentrated along the edges and are splayed outwards by default, increasing the chances of actually tangling with a neighbor. Members of Tesseleaf mats are fused into a superorganism which shares a nervous system and nutrients.
The nervous system of Tesseleaves runs through the long hairs that tangle them together with their neighbors. When disturbed, such as by a predator, an alarm signal is sent through all neighboring leaves and they immediately begin to produce a toxin which tastes very bitter and causes indigestion. Many may still be eaten before they produce enough to fully deter predators, but it is still sufficient to prevent the entire mat from being devoured.
There are many species of Tesseleaves. They generally lack much in terms of temperature adaptations, though they are absent in tundras; they mainly just vary in color to match light intensity. Species in areas with fewer predators tend to be less toxic. They are found in most aquatic environments in Hybarder and can be compared to Terran duckweed. They spread between them when their spores are accidentally consumed by flying creatures such as Spardiflies which drink from the watersheds, eventually exiting their bodies through droppings. This is possible because of the cellulose cell walls of the spores. Most spores are dissolved by stomach acid, but some survive, allowing them to be spread in this manner.