Herbs 25–55 cm tall.
Leaves 3–4, ellipticlanceolate, to 35 × 3 cm.
Inflorescences dense tightly spiraled spikes, generally 3-ranked, 10–60-flowered; rachis glabrous to sparsely pubescent.
Flowers ascending, sepals and petals lanceolate, creamy-yellow to yellowish, converging with lip to form a tube, tips spreading, 7–8 × 1–2.5 mm; lateral sepals oblique; lip ovate to lanceolate, concave to loosely folded with a narrowed apex, 6–8 × 3–4 mm.
2n=44.
Stream banks, river banks, seeps, riparian meadows. Flowering Jun–Jul. 0–2700m. Casc, CR, Sisk, WV. CA, ID, NV, WA. Native.
The spreading perianth tips and narrow-tipped lip distinguish this species from the more common S. romanzoffiana.
as described under Spiranthes porrifolia
Plants 15-60 cm. Roots few-several, spreading to descending, tuberous, mostly to 1 cm diam. Leaves persisting through anthesis or fugaceous, basal, often on proximal portion of stem, ascending, linear to linear-lanceolate, linear-oblanceolate, oblanceolate or elliptic, to 34 × 3.5 cm. Spikes usually very tightly spiraled, rarely loosely spiraled, usually 3 flowers per cycle of spiral; rachis glabrous to sparsely pubescent, trichomes less (usually much less) than 0.18 mm, capitate glands often sessile. Flowers ascending, creamy to markedly yellowish, slenderly tubular; sepals connate at base, 4.6-11 mm, apex reflexed-spreading; petals linear-lanceolate to linear-oblanceolate, apex reflexed-spreading, obtuse to subacute or subemarginate; lip lance-ovate to lanceolate, 4-9.5 × 1.9-4.3 mm, apex recurved less than to scarcely more than apices of sepals and petals, only slightly or not at all dilated, with subapical dense cushion of peg-shaped trichomes on adaxial surface; veins few to several, branches wide-spreading or often parallel; viscidia linear to linear-elliptic; ovary mostly 2-7.5 mm. Seeds monoembryonic. 2n = 44 [66].Flowering May--Aug. Moist to wet riparian meadows, stream banks, marshes, fens, seeping banks; 100--2600 m; Calif., Idaho, Nev., Oreg., Wash.