1. Hypericum adpressum Raf. ex W.P.C. Barton (creeping St. John’s wort)

Map 1561

Plants perennial herbs, the rootstock and stem bases occasionally somewhat spongy but not woody, with well-developed, long-creeping rhizomes. Stems scattered along the rhizomes, occurring singly, 30–80 cm long, erect or ascending, angled or slightly ridged below each leaf toward the tip, rounded toward the base, reddish brown, the surface usually not peeling with age. Leaves not jointed at the base. Leaf blades 20–80 mm long, 2–12 mm wide, narrowly oblong to narrowly elliptic, bluntly to sharply pointed at the tip, tapered or narrowed at the base, the margins somewhat rolled under at maturity, herbaceous to somewhat leathery in texture, with 3 main veins usually visible toward the base, the surfaces lacking noticeable black dots, lines, or streaks but usually with minute, faint, pale dots visible, the upper surface green, the undersurface usually pale green, but not glaucous. Inflorescences appearing as panicles of 13–80 flowers, rounded to more or less flat-topped in outline. Flowers actinomorphic. Sepals 5, all more or less similar in size and shape, 3–7 mm long, not becoming enlarged at fruiting, lanceolate to ovate, the margins occasionally slightly curled, lacking noticeable black dots, lines, or streaks. Petals 5, 6–8 mm long, broadly oblanceolate to obovate, bright yellow, usually shed before fruiting. Stamens 60–80, the filaments not fused into groups. Ovary 1-locular or appearing partially 3-locular by intrusion of the parietal placentae into the locule. Styles 3(4), sometimes fused toward the base, erect and more or less appressed at flowering, persistent and usually separating somewhat as the fruit matures, the stigmas minute. Fruits 3.5–6.0 mm long, ellipsoid to ovoid, widest at or slightly below the midpoint, tapered abruptly to the minute beak (this sometimes absent), more or less circular in cross-section. Seeds numerous, 0.6–0.8 mm long, the surface with a network of ladderlike columns of fine ridges and pits, dark brown to nearly black. 2n=18. July–August.

Uncommon, known only from Mississippi and Scott Counties (eastern U.S. west to Illinois, Missouri, and Alabama). Moist depressions in sand prairies; also sandy banks of ditches.

Adams (1962) reported the presence of this species in southeastern Missouri, but it was overlooked by Steyermark (1963) and Yatskievych and Turner (1990). John Kartesz (Biota of North America Program) was the first to note this omission from the Missouri literature.