Platanthera dilatata
Bot. North. Middle States, 347. 1833.
Plants 11–130 cm or more. Leaves few–several, ascending to recurved-spreading, scattered along stem, gradually reduced to bracts distally; blade linear, linear-lanceolate, oblong, or oblanceolate, 3.5–32 × 0.3–7 cm. Spikes very lax to very dense. Flowers resupinate, rather showy, conspicuous, white; lateral sepals spreading to reflexed; petals ovate- to linear-lance-falcate, margins entire; lip descending or apex adhering to dorsal sepal and petal apices, linear-lanceolate to lanceolate, without basal thickening, 4–11 × 2–5 mm, base slightly rounded-dilated to orbiculate, rarely rhombic, margins entire; rostellum lobes parallel to slightly divergent, directed downward, very small, obscure, rounded; pollinaria straight; pollinia remaining enclosed in anther sacs; ovary rather slender to stout, 5–15 mm. 2n = 42.
Distribution
St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Alaska, Calif., Colo., Conn., Idaho, Ill., Ind., Maine, Mass., Mich., Minn., Mont., Nev., N.H., N.Mex., N.Y., Oreg., Pa., S.Dak., Utah, Vt., Wash., Wis., Wyo.
Discussion
Varieties 3 (3 in the flora).
Selected References
None.
Lower Taxa
Key
| 1 | Spur shorter than lip, clavate to slightly capitate. | Platanthera dilatata var. albiflora |
| 1 | Spur nearly equaling to exceeding lip, slender to slightly clavate. | > 2 |
| 2 | Spur about equal to lip (mostly within 2 mm). | Platanthera dilatata var. dilatata |
| 2 | Spur markedly exceeding lip (commonly 11/2 or more times length of lip). | Platanthera dilatata var. leucostachys |