54. Hypericum pseudomaculatum Bush ex Britton, Man. Fl. N. States. 627. 1901.
Hypericum punctatum Lamarck var. pseudomaculatum (Bush ex Britton) Fernald
Herbs erect or ascending to divaricate, with rooting, sometimes creeping, branching base, 4–9.5 dm. Stems <sometimes clustered>, internodes not lined, with black glands scattered all over. Leaves usually ascending, sometimes spreading, sessile; blade usually ovate-lanceolate to triangular-lanceolate or narrowly elliptic, rarely ovate, 18–45 × 6–16(–20) mm, base cordate to rounded, margins plane, apex usually acute, rarely obtuse to rounded, midrib with 3–4 pairs of branches, <tertiary veins densely reticulate toward margins>, black glands intramarginal (dense) and laminar (scattered). Inflorescences subcorymbiform to broadly pyramidal, 16–164(–280)-flowered, <subsidiary branches ascending to widely spreading>. Flowers 10–20 mm diam.; sepals not imbricate, erect in fruit, lanceolate to ovate or elliptic-oblong, subequal, (3–)3.7–4.9(–6) mm, apex acute; petals yellow, usually obovate, rarely elliptic, 6–14 mm; stamens 38–61; anther gland amber or pellucid; styles 5.4–8.5 mm. Capsules broadly ovoid, 3–6 × 2–4 mm, with longitudinal and lateral vittae or vesicles or only ovoid vesicles (all amber). Seeds not or scarcely carinate, 0.6–0.8 mm; testa linear-reticulate. 2n = 16.
Flowering mid summer (Jun–Jul). Open and partially shaded, dry areas of woods, among rocks, fields, roadsides, well-drained soil; 100–700 m; Ala., Ark., Fla., Ga., Ill., La., Miss., Mo., Okla., S.C., Tenn., Tex.
Hypericum pseudomaculatum has been confused with H. punctatum; they are quite distinct and they rarely, if ever, hybridize. The affinities of H. pseudomaculatum are with Mexican H. formosum Kunth.
J. A. Steyermark (1963) recognized two distinct floral forms in Missouri: forma pseudomaculatum with orange-yellow petals and stamen filaments, and forma flavidum in which these parts are pale, creamy yellow. The distribution of these two forms within the whole range of the species is unknown.