Favoritos de willhendricks

Plants tiny. Forming a bright green carpet in drying vernal pools.
Leaves 1-2 cm in length, pliant (not rigid or brittle).
Velum covering entire sporangium.
Sporangium wall unpigmented.
Megaspores white to gray, lustrous, 300-350 μm in diameter, smooth to obscurely tuberculate.

Plants numerous, but scattered. Growing in sand, silt, and gravel in 0.5 to 1 meter of water.
Leaves 6-10 cm in length.
Megaspores 450--550 μm in diamemter; uniformly echinate, spines thin and sharp, not reduced near the equator; girdle obscure.
Ligule conspicuous, deltoid, >1 mm long.

Note: Isoetes echinospora was previously recorded at Lake Padden by legendary botanist/plant collector Wilhelm Suksdorf in 1890.