Hypericum mutilum var. latisepalum Fernald, Rhodora 38: 372. 1936

Stems: apical internode usually longer than adjacent one. Leaf blades broadly ovate or broadly oblong-ovate to suborbiculate. Inflorescences: branching from 1–4(–6) nodes, branches diffuse and repeatedly monochasial distally. Sepals ± imbricate, broader beyond middle.

Flowering late spring–early summer (Apr–Jun). Ditches, marshes, lake margins, desiccated temporary pools; 0–200 m; Fla., Ga., N.J., S.C., Tex.

Fernald recorded subsp. latisepalum from New Jersey; D. H. Webb (1980) did not record it north of South Carolina. No specimens have been seen from farther north than Georgia, where it appears to tend morphologically toward subsp. mutilum.