Narrowleaf rhombopod

Plants (30-)40-150(-200) cm. Stems sparsely branched distally (central stem dominant); glaucous, glabrous. Leaves: stipules (± deciduous) 2-4-fid, 0.5-1 mm (scarious); petiole 0.7-2.8 cm; leaflet blade linear to elliptic, 2.3-5.5 × 0.2-0.8 cm, thin, margins entire, apex acute, surfaces glabrous. Inflorescences racemes, terminating stems and branches, 1-6 cm (10-40 cm in fruit); bracts trifoliate proximally, unifoliate distally, 7-15 mm. Pedicels reflexed in fruit, 5-10 mm (6-13 mm in fruit). Flowers: sepals yellow, deltate, 1-2.2 × 0.5-1 mm, glabrous; petals orange-yellow, ovate, (3-)4-5(-6) × 1-2 mm, glabrous; stamens yellow, 7-10 mm; anthers 1.5-2.2 mm; gynophore reflexed, 4-7 mm in fruit; ovary rhomboidal, 1-1.5 mm; style 0.3-0.5 mm. Capsules rhomboidal, 4-6 × 6-12 mm, glabrous. Seeds 2-4(-6), gray with black mottling, reniform, 2-3 mm, rugose.

Flowering mid spring-summer. Pond shores, stream bottoms, roadsides, grasslands, heavy alkaline clayey or sandy soils; 200-1200 m; Colo., Kans., Nebr., Okla., Tex.