Plant body ovoid, ellipsoid, or ovoid-cylindrical, upper surface barely rounded (flattened along top), 0.4–0.8 mm long, 1.3–2 times as long as wide, 1–1.5 times as deep as wide, greatest width slightly below the water surface, with 1–10(–30) stomata, pale and somewhat transparently green on the water surface. Brown epidermal pigment cells absent. Flowers rare.

Smallest of all known flowering plants. Found floating at the surface of quiet streams and ponds in full sun, often mixed with other small aquatic plants such as Lemna spp.
Normally harvested from natural waterways for home consumption; occasionally sold in local markets throughout Thailand and People’s Democratic Republic of Lao. In Thailand, they are cooked in curries such as kaeng pham (minced pork or chicken curry) or khua pham (stir-fried pham northern style).