VERY weird. A big muddy pool in which the dominant vegetation is a large isoetes. Not looking like nutallii, but seemingly capable of withstanding drying, not sure what that leaves me with. Howellii seems wrong too.
This is from the same location as an observation by @oxalismtp: https://www.inaturalist.org/observations/111926271
Leaves bright green, pale to brown toward base, pliant, gradually tapering to tip. Hyaline leaf margins extending 1–5 cm above sporangium. Rootstock nearly globose, 2-lobed. Velum covering less than 1/2 of sporangium. (Velum coverage best visualized in the longitudinal section of photos 10 and 11.) Sporangium wall brown-streaked to completely brown. Megaspores white, 350--400 μm diameter, obscurely tuberculate to rugulate; girdle smooth.
In vernal pool
Probably I. nuttalii.
The ponds in the temporary ponds in Harris Savanna is currently active.
Floating on lake surface. Possibly dislodged by a large group of CAGOs.