12. Spiranthes ochroleuca (Rydberg) Rydberg, Fl. Plains N. Amer. 241. 1932.
Gyrostachys ochroleuca Rydberg in N. L. Britton, Man. Fl. N. States, 300. 1901; Spiranthes cernua (Linnaeus) Richard var. ochroleuca (Rydberg) Ames; Spiranthes × steigeri Correll
Plants 10–55 cm. Roots few, horizontally spreading, slender, mostly to 0.4 cm diam. Leaves persisting through anthesis, basal, sometimes on basal portion of stem, spreading, linear-oblanceolate to narrowly elliptic, to 21 × 2 cm. Spikes rather loosely to very tightly spiraled, 3–4 flowers per cycle of spiral, occasionally 5 or more in very loose spiral; rachis moderately pubescent, some trichomes capitate, glands obviously stalked. Flowers ochroleucous, ivory, creamy, yellowish, or greenish white, ascending, urceolate to somewhat gaping, claw of lip at pronounced (20–60°) angle to lamina, base cuneate, appearing strongly inflated; sepals distinct to base, 6–14 mm; lateral sepals appressed to petals and lip, straight, separated from dorsal sepal by mostly 0.7–1 mm; petals linear to linear-oblong, 6–13 mm, apex acute to obtuse; lip often more yellow centrally, oblong to ovate, 7–12 × 4–7 mm, margins crenulate, glabrous; veins several, branches parallel; basal calli incurved, prominent, very rarely conic, 1–2 mm; viscidia linear; ovary 3–7 mm. Seeds monoembryonic. 2n = 30.
Flowering Aug--Nov. Dry to mesic open woodland, thickets, meadows, barrens, ledges, outcrops, banks and roadsides, old fields; 0--1700 m; N.B., N.S., Ont., P.E.I.; Conn., Ind., Ky., Maine, Md., Mass., Mich., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va.
While leaves of Spiranthes ochroleuca are usually present at anthesis, in prairie populations they are commonly absent.
Spiranthes × steigeri was described as a hybrid of S. cernua and S. romanzoffiana, but additional study (P. M. Catling 1984) has shown the plants to be referable to S. ochroleuca.
See notes on gene flow and apomixis under 14. Spiranthes cernua.
Hybrids of Spiranthes ochroleuca with S. casei are known as S. × borealis P. M. Brown.
Catling, P. M. 1984. A re-evaluation of Spiranthes ×steigeri. Rhodora 86: 469–473. Sheviak, C. J. and P. M. Catling. 1980. The identity and status of Spiranthes ochroleuca (Rydberg) Rydberg. Rhodora 82: 525–562.