Mauvecostrum
Most of the small continent of Hydro lacked any purple flora (aside from decomposers), with parts lacking any photosynthesizers at all. However, the savanna at the southern end contained some pale mycostrums, which had dispersed across the narrow channel. Finding an open niche, these spread across the tropical and subtropical parts of Hydro, forming the new ground cover. While they retained the ability for detritivory, they returned to specializing in photosynthesis. This new species, the mauvecostrum, replaced their ancestor within their shared environment, being better at photosynthesis while the ghost mycostrums were better at detritivory.
Mauvecostrums will grow in patches on the ground, extending upward to form a squishy covering upon the soil. They can still form paler tissue, which is not adapted for photosynthesis. They use this for roots, forming a vast underground network, and for the stalks that support their fruiting bodies, which form once an individual has matured. These fruiting bodies form oblong shapes that are themselves capable of photosynthesis, as they would otherwise shade the base of the organism too much. Growths on the fruiting body extend into tiny, short streamers. At first, these produce gametes, scattered by the wind until they land on another mauvecostrum. This fertilizes it, allowing its fruiting bodies to produce spores, which are further scattered by the wind. They also reproduce vegetatively, as their roots form runners, allowing them to extend in large patches in nearby areas.
During particularly dry, parched times (which happen most years in the savanna and chaparral), they tend to wither and go dormant, or even die back entirely. As they have hardy spores, their population easily rebounds once the rain returns.