Hypericum erythreae
Perennial herb 0.4-1(-1.1) m tall. Stems reddish-brown to orangish or tan, erect to ascending usually branched above, spongy thickenend at base; lower internodes usually shorter than leaves. Leaves sessile to subamplexicaul, 10-35(-40) x 3-8(-12) mm, appressed or strongly ascending, lanceolate to oblong-elliptic or obovate, acute to obtuse. Sepals 3-3.5 x 1.5-2.5 mm, narrowly ovate to lanceolate, acute to acuminate. Petals yellow to yellow-orange, 6-10 x 5-6 mm. Seeds (0.5)0.6- 0.8(0.9) mm long.
2n = 24 (n = 12 - Webb, 1980).
Dry roadsides, fields, and open woods; 0-c. 700 m (or higher?).
South-eastern U.S.A. (Maryland to southern Illinois and south to Florida and Louisiana; not east coastal).
The Florida collections ('H. virgatum var. revolutum" R. Keller) have the small flowers and narrow leaves of H. harperi but not the spongy stem base, thus indicating that, although morphologically intermediate in some respects, the habit is dry like that of H. denticulatum subsp. acutifolium.