Prairie pinkroot

Coelostylis lindheimeri (A. Gray) Small; Spigelia lindheimeri A. Gray

Herbs perennial, 5–15(–19) cm; rhizomes slender. Stems 3+, usually branched. Cauline leaves: proximals 3 or 4 pairs per stem, sessile to attenuate-petiolate; blade oblanceolate, lanceolate, ovate, or elliptic, (1.2–)1.5–3(–3.5) × 0.3–1(–1.3) cm, base narrowly cuneate; distals usually opposite, sometimes pseudowhorled. Cymes 2-flowered. Flowers: calyx lobes linear to linear-lanceolate, 3–6 mm; corolla white, suffused or lined with pink or yellow outside, white inside, funnelform, 7–13 mm,; lobes spreading at anthesis. Capsules 2–4 × 4–6 mm. Seeds 1–2 mm.

Flowering Apr–Jun. Open prairies or dry woods on thin, rocky or sandy soils; 10–600 m; Tex.; n, c Mexico.

Spigelia hedyotidea, of central-western Texas and northern to central Mexico, is most closely related to S. texana of eastern Texas (K. R. Gould and R. K. Jansen 1999). It can be distinguished from S. texana by its bushy growth habit with more than three stems from the base (versus one to three stems), its usually profusely scabrous (versus glabrous) stems, and its paired (versus pseudowhorled) leaves that subtend the inflorescence.