Wetlands and marshes have consistent groundwater discharge which means that water levels will typically be high in these areas. This will result in anoxia and ultimately lower the amount of nutrients present. It is thought that the plants evolved to endure these conditions so that they have less competition for sunlight. While "T. laxus" prefers these wetter conditions, the plant can also grow in drier conditions if there is enough sunlight present. Increased sunlight will increase the biomass of these plants but, there is a threshold before the plant’s growth will plateau or even decline. The combination of seasonal drying along with very high light intensities can result in the competitive exclusion of "T. laxus" . In order for "T. laxus" to meet this requirement of light intensity and hydrology, it must sacrifice the size of its range. This is a factor that causes it’s distribution to be limited. 