Roots dark brown, to 8 per plant, 0.8-1.3 mm diam., producing proliferations. Stem upright, 0.3-1 cm, 1.5-2.5mm diam., 2-3 leaves per stem. Trophophore stalk 0-3mm, 0-0.1 times length of blade. Trophophore blade erect to spreading, usually plane or nearly so when alive, gray-green, dull, ovate to trowel-shaped, to 6 × 3cm, fleshy, cuneate to truncate to nearly cordate at base, contracted gradually to acute apex, apiculum mostly absent; venation coarse, reticulate, areoles large with few free or anastomosing included veinlets. Sporophores arising at ground level, 0.8-7 times length of trophophore; sporangial clusters to 4 × 0.35 cm, with up to 30 pairs of sporangia, apiculum 0.3-1.2 mm.
Leaves appearing during wet periods. Plants sometimes weedy in lawns, ditches, and around buildings; 0-90m; introduced; Ala., Ark., Fla., Ga., La., Miss., Mo., N.C., Okla., S.C., Tex., Va.; West Indies; Mexico; n South America; Asia; Pacific Islands.
Ophioglossum petiolatum grows readily in pots, making it suitable for botany instruction. Earliest records in North America date from 1900 to 1930, suggesting that it is probably introduced.