13. Linum intercursum E. P. Bicknell, Bull. Torrey Bot. Club. 39: 418. 1912.
Sandplain flax, Bicknell's yellow flax Sandplain flax, Bicknell's yellow flax
Cathartolinum intercursum (E. P. Bicknell) Small
Herbs or subshrubs, perennial, 20–92 cm, glabrous. Stems erect, unbranched proximal to inflorescence or few-branched at base. Leaves: proximalmost opposite, distalmost alternate, sometimes opposite nearly to inflorescence, erect to ascending; stipular glands absent; blade narrowly elliptic to oblanceolate, 8–27 × 1.2–5.6 mm, margins entire, not ciliate, apex acute; internal venation shown by transmitted light. Inflorescences panicles. Pedicels 0–5 mm. Flowers: sepals persistent, lanceolate, 2–3 mm, margins not scarious, entire, or inner and rarely outer sparsely glandular-toothed, apex sharp-pointed; petals yellow, obovate, 4–7 mm; stamens 3 mm; anthers 0.5–1 mm; staminodia absent; styles distinct, 1.5–2.5 mm; stigmas capitate. Capsules turbinate, 2–3 × 2–2.3 mm, apex acute or obtuse, dehiscing freely into 10, sharp-pointed 1-seeded segments, segments persistent on plant, false septa incomplete, proximal margins sparsely but conspicuously ciliate. Seeds 1.3–1.8 × 0.6–0.9 mm. 2n = 36.
Flowering Jun–Oct. Clay, sandy, siliceous, or peaty shores; dry, clay or sandy soils in clearings; coastal sandplains and shrubby grasslands, open forests, woodlands, roadsides; sometimes in alternately wet and dry, hardpan soils; 0–800 m; Ala., Conn., Del., D.C., Ga., Ind., Md., Mass., N.J., N.Y., N.C., Pa., R.I., S.C., Tenn., Va.
Linum intercursum is sometimes confused with L. floridanum, from which it differs by its pointed capsule and broader leaves. All parts of the flower of L. intercursum are yellow, and the corolla is nearly rotate.