Platanthera obtusata |
Platanthera huronensis |
|
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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 |
great lakes rein orchid, green bog orchid, Huron green orchid, Lake Huron bog green orchid, northern green bog-orchid |
|
Habit | Plants 5.5–35 cm. | Plants 10–100 cm or more. |
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, ascending, scattered along stem, gradually reduced to bracts distally; blade oblong to linear-lanceolate, 5–30 × 0.6–7 cm. |
Spikes | lax. |
very lax to very 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 but sometimes conspicuous, whitish green; corolla often whiter than calyx; lateral sepals spreading to slightly reflexed; petals ovate- to lance-falcate, margins entire; lip descending or apex adhering to dorsal sepal and petal apices, lanceolate to nearly linear, without basal thickening, 5–12 × 2–4 mm, base slightly to rather markedly rounded-dilated, margins entire; spur slenderly cylindric to clavate, 4–12 mm, apex usually slenderly tapered; rostellum lobes divergent, directed downward, very small, obscure, rounded; pollinaria straight; pollinia remaining enclosed in anther sacs; viscidia oblong; ovary rather slender to stout, mostly 6–15 mm. |
2n | = 42, 63 (American, as Habenaria obtusata), 126 (Eurasian, as Habenaria obtusata). |
= 84. |
Platanthera obtusata |
Platanthera huronensis |
|
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) | 0–3300 m (0–10800 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; CO; CT; ID; MA; ME; MI; MN; MT; NH; NJ; NM; NY; OR; RI; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; YT
|
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.) |
Northwestern plants commonly treated as Platanthera hyperborea var. viridiflora (Chamisso) Kitamura (note Kitamura’s priority over Luer) are P. huronensis; Chamisso’s name furthermore is synonymous with P. stricta. Aleutian and coastal Alaskan plants are often short, stout, and broad-leaved, and they have incorrectly been referred to 9. P. convallariifolia. Platanthera huronensis as here delimited does not auto-pollinate in the manner of P. aquilonis. Occasional plants and populations that may be referable to P. huronensis, however, exhibit the movement of pollinia typical of P. aquilonis. These plants might reflect infraspecific variation within an allotetraploid species, result from hybridization, or constitute a distinct taxon. The relationship of some of these plants to P. hyperborea needs study. Platanthera huronensis is typically intensely fragrant with the sweet, pungent scent of some related species. Platanthera huronensis is known to hybridize with P. dilatata; it may hybridize with other species as well. Although hybrids of P. dilatata and P. aquilonis may occur, the name traditionally used for them, P. ×media (Rydberg) Luer is a synonym of P. huronensis. See notes under 10. P. aquilonis and 8. P. hyperborea. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 556. | FNA vol. 26. |
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 | Orchis huronensis, Habenaria hyperborea var. huronensis, Habenaria ×media, Limnorchis media, P. hyperborea var. huronensis, P. ×media |
Name authority | (Banks ex Pursh) Lindley: Gen. Sp. Orchid. Pl., 284. (1835) | (Nuttall) Lindley: Gen. Sp. Orchid. Pl., 288. (1835) |
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