Stem slender and creeping, rootless, densely covered with brown, jointed, short hairs. Leaves arranged in a whorl of three, with two floating on the water surface and one finely divided like silk, forming pseudo roots in the water. These leaves are densely covered with jointed, coarse hairs. The water surface leaves are closely arranged on both sides of the stem, resembling the leaves of a catalpa tree. Leaf blades are broadly ovate or elliptic, 8-13 cm long, 5-8 mm wide, with a rounded apex and a broadly rounded or slightly cordate base. The midrib is distinct, with about 20 pairs of lateral veins, and 5-9 prominent points between the veins, each bearing a tuft of coarse, short hairs. The margin is entire, the upper surface green, the lower surface grayish-brown, and covered with jointed, coarse, short hairs. Petioles are about 2 mm long.

The sporocarps, ranging from 4 to 8 in number, are clustered at the base of submerged leaves. They vary in size, with the large sporocarps being smaller, each containing a few large sporangia with a short stalk, each holding one large spore. The small sporocarps are slightly larger, bearing numerous small sporangia with a long stalk, each containing 64 small spores.