Spiranthes cernua (L.) Rich.

  • Authority

    Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

  • Family


  • Scientific Name

    Spiranthes cernua (L.) Rich.

  • Description

    Species Description - Plants 1–4(–8) dm; basal lvs narrow, to 30 cm, 5–50 mm wide; cauline sheaths 3–8, sometimes with a spreading-recurved blade; infl 2–18 cm, with shortly glandular- hairy axis, dense, the fls ± in 3 or 4 vertical ranks, 8–11(–15) mm, individually widely spreading or somewhat declined, urceolate-cylindric, only the upper sep and lateral pet connivent, the lateral sep looser but scarcely spreading; lip moderately to sometimes (var. ochroleuca) strongly arcuate-recurved, ovate or ovate-oblong or obcuneate, often dilated and cordate at base, erose or crisped around the broad summit, somewhat yellowish- green in the center, the fls otherwise white or whitish (or more ochroleucous in var. ochroleuca); callosities at base of lip often 1 mm or more, higher than thick; viscidium 1–2 mm, narrow; 2n=30, 45, 60, 61, the plants often asexual. Open, moist, often sandy places; N.S. and Que. to se. N.D., s. to Fla. and Tex. Aug., Sept. Common, variable, and imperfectly divisible into an indefinite number of ecogeographic phases. Robust, diploid plants, to 8 dm, with fls 10–14 mm, often spreading by stolon-like roots, and with the cauline sheaths bearing spreading, ± recurved blades, mainly on the se. coastal plain, often in estuaries, form the ill-defined var. odorata (Nutt.) Correll; the fls are said to have the odor of vanilla, in contrast to the inodorous fls of others vars. (S. odorata) Plants with slightly more yellowish fls and a strongly decurved lip with a relatively long claw (0.8–1.5 mm, in contrast to 0.3–0.8 mm in var. cernua) thought to be mainly diploid but not always sexual, occurring from P.E.I. and s. N.S. to Mich., s. to Ky. and the mts. of Va. and N.C., have been distinguished as var. ochroleuca (Rydb.) Ames. (S. ochroleuca; S. steigeri)

  • Common Names

    nodding ladies'-tresses