1. Pilularia americana A. Braun (pillwort) Pl. 8c,d; Map 43

Roots only at nodes of the rhizome. Leaves 2–10 cm long, filiform, lacking leaf blades, glabrous to sparsely pubescent. Sporocarps 1.5–3.0 mm in diameter, globose, hairy or becoming nearly glabrous, lacking a well-defined tooth at the attachment point, arising 1 per node from the base of the petiole on an unbranched peduncle 1–3 mm long, pendant, and subterranean. May–October.

Uncommon in Barton and Lincoln Counties (western, central, and southeastern U.S., northwestern Mexico). Submerged aquatic or stranded on mud along margins of ponds.

This species often goes unnoticed because of its short, grasslike leaves and subterranean sporocarps. It should be found at other sites in the future. The most reliable field character to distinguish Pilularia from various species of grasses, Eleocharis, and Juncus that grow with it is the young leaves, which uncurl in a fiddlehead fashion, as do those of most other ferns.