Platanthera obtusata |
Platanthera stricta |
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blunt-leaf bog-orchid, blunt-leaf rein-orchid, blunt-leafed rein orchid, bluntleaf orchid, northern small bog orchid, one-leaf rein-orchid, small northern bog-orchid |
canyon bog orchid, needle-spur green orchid, slender bog-orchid, slender rein orchid |
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Habit | Plants 5.5–35 cm. | Plants 18–100 cm. |
Leaves | 1(–2, rarely), spreading-ascending on base of stem; bracts 0(–1, rarely); blade linear-oblanceolate, elliptic, or broadly obovate, 3.5–15 × 0.8–5 cm. |
few–several, abruptly diverging or sometimes ascending, scattered along stem; blade oblong to ovate or rarely linear-lanceolate, 3–32 × (0.6–)1–4.5 cm. |
Spikes | lax. |
very lax to dense. |
Flowers | resupinate, not showy, greenish white to yellowish green; corolla commonly whiter than calyx; lateral sepals reflexed; petals rhombic, lanceolate-falcate, margins entire; lip descending, linear, narrowly lance-rhombic, or linear-hastate, with median basal thickening, unlobed, 2.5–8(–10) × less than 1–2 mm, margins entire; spur slenderly conic, 3–8(–10) mm; rostellum lobes directed forward, wide-spreading, rounded-angular; pollinaria straight; pollinia remaining enclosed in anther sacs; viscidia orbiculate; ovary rather slender to stout, mostly 3–10 mm. |
resupinate, not showy, green to yellowish green; lateral sepals spreading to reflexed; petals ovate- to lance-falcate, margins entire; lip descending to somewhat reflexed or projecting, linear to lanceolate, without basal thickening, 3–9 × less than 1–3 mm; spur strongly clavate, capitate-inflated, or scrotiform, 2–6 mm, apex obtuse; rostellum lobes approximately parallel to convergent, directed downward, very small, rounded, obscure; pollinaria straight; pollinia remaining enclosed in anther sacs; viscidia orbiculate; ovary rather slender to stout, mostly 5–10 mm. |
2n | = 42, 63 (American, as Habenaria obtusata), 126 (Eurasian, as Habenaria obtusata). |
= 42. |
Platanthera obtusata |
Platanthera stricta |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Mesic to wet coniferous forest, forested fens, sphagnum bogs, stream banks, tundra, moist roadsides | Wet meadows, tundra, marshes, fens, stream banks, shores, ditches, seeping slopes, roadsides |
Elevation | 0–3500 m (0–11500 ft) | 0–2300 m (0–7500 ft) |
Distribution |
AK; CO; ID; MA; ME; MI; MN; MT; NH; NY; OR; UT; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; Eurasia [Platanthera obtusata subsp oligantha]
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AK; CA; ID; MT; OR; WA; WY; AB; BC; YT
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Discussion | The rare Eurasian Platanthera obtusata subsp. oligantha (Turczaninow) Hultén differs from the North American subsp. obtusata in its smaller dimensions and rhombic-lanceolate lip. It is also said to be densely few-flowered, although some Siberian material is comparable to American plants. Supposedly intermediate plants are reported from Alaska, and much material from that area is reduced in stature and with smaller flowers than typical of American plants. In most cases, however, lips are relatively slender, and the plants seem merely to be stunted by their environment. One or two collections from the Alaskan Peninsula and Aleutians, however, seem entirely referable to subsp. oligantha with dense, few-flowered inflorescences of very small flowers with rhombic-lanceolate lips and shorter curved spurs. Eurasian plants are reported to be hexaploid or perhaps sometimes triploid, and if the apparent ploidy differences delimit the taxa, then it should be possible to unequivocally identify Alaskan plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Flowers of Platanthera stricta are evidently mostly scentless or only faintly spicy. The plants here treated as Platanthera stricta have in common more or less saccate spurs, orbiculate viscidia, and leaves that abruptly diverge from the stem, often at angles approaching 90º (this feature is sometimes obscured in sheltered, deeply shaded habitats). The plants described as P. gracilis Lindley are florally typical of the slender-spurred extreme of P. stricta; they differ only in peculiarly reduced, slenderly oblong but nonetheless abruptly wide-spreading leaves. The plants figured by C. A. Luer (1975) as P. hyperborea var. gracilis (Lindley) Luer are not referable to P. stricta but rather are apparently hybrids of P. stricta and P. dilatata. Critical study of the description of Habenaria borealis var. viridiflora Chamisso and an evident isotype show this plant to be referable to P. stricta, although the name has been applied to P. huronensis in the Northwest and to P. convallariifolia in Japan. See also the discussion under 9. P. convallariifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 556. | FNA vol. 26, p. 560. |
Parent taxa | Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera | Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera |
Sibling taxa | ||
Synonyms | Orchis obtusata, Habenaria obtusata, Habenaria obtusata var. collectanea | Habenaria borealis var. viridiflora, Habenaria saccata, Limnorchis stricta, P. gracilis, P. hyperborea var. viridiflora, P. hyperborea var. viridiflora, P. saccata |
Name authority | (Banks ex Pursh) Lindley: Gen. Sp. Orchid. Pl., 284. (1835) | Lindley: Gen. Sp. Orchid. Pl., 288. (1835) |
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