4. Linum striatum Walter

Pl. 446 a, b; Map 2021

Plants perennial. Stems 20–80 cm long, solitary or few, glabrous, finely longitudinally ridged or lined (angled in cross-section) above the midpoint, with small wings of tissue descending from an extension of each leaf midvein. Leaves mostly opposite below the stem midpoint, alternate above. Stipules absent. Leaf blades 1.5–3.5 cm long, (3–)5–12 mm wide, elliptic, narrowed to a sharply pointed tip, the margins entire. Sepals 1.5–3.5 mm long, elliptic, those of the outer whorl with entire margins, those of the inner whorl mostly entire but sometimes with inconspicuous minute teeth above the midpoint, these occasionally somewhat glandular. Petals 3–5 mm long, pale yellow to light yellow. Styles distinct, 1.2–2.0 mm long. Fruits readily shattering, falling from the plant soon after maturity, 1.3–1.9 mm long, 1.8–2.3 mm in diameter, depressed-globose, breaking into 10 mericarps, each 1-seeded, rounded across the dorsal surface, the septa glabrous, the mature fruits lacking purple stripes. Seeds 1.0–1.5 mm long, reddish brown. 2n=36. May–September.

Scattered to uncommon in the southeastern quarter of the state (eastern U.S. west to Illinois, Oklahoma, and Texas; Canada). Fens, banks of streams and rivers, and bottomland forests.