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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

eagle rein orchid, north wind bog-orchid, northern bog orchid, northern green bog orchid, northern green orchid, northern green rein orchid, Sheviak's bog orchid

Habit Plants 5.5–35 cm. Plants 5–60 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, ascending to arcuate-spreading, scattered along stem, gradually reduced to bracts distally;

blade oblong to linear-lanceolate, 2.7–23 × 0.4–4 cm.

Spikes

lax.

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, yellowish green with dull yellowish lip, or more whitish green under cool conditions;

lateral sepals spreading to reflexed;

petals rhombic-ovate- to lance-falcate, margins entire;

lip descending, projecting, or apex adhering to dorsal sepal and petal apices, rhombic-lanceolate to lanceolate, without basal thickening, 2.5–6 × 1–1.5 mm, base not rounded-dilated, margins entire;

spur clavate or sometimes rather cylindric, 2–5 mm, apex usually broadly obtuse;

rostellum lobes divergent, directed downward, very small, rounded, obscure;

pollinaria straight;

pollinia rotating forward and/or fragmenting, loose pollen masses free of anther sacs and trailing downward onto stigma;

viscidia orbiculate;

ovary rather slender to stout, mostly 5–13 mm.

2n

= 42, 63 (American, as Habenaria obtusata), 126 (Eurasian, as Habenaria obtusata).

= 42.

Platanthera obtusata

Platanthera aquilonis

Phenology Flowering Jun–Aug. Flowering May–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, borrow pits, mesic deciduous forest slopes
Elevation 0–3500 m (0–11500 ft) 0–2500 m (0–8200 ft)
Distribution
from FNA
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]
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CO; CT; IA; ID; IL; IN; MA; ME; MI; MN; MT; ND; NE; NH; NJ; NM; NY; OH; OR; PA; RI; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
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 aquilonis are usually scentless, but in the far northwest they have a sweet, pungent scent, like that of some related species. The flowers are commonly self-pollinating: the pollinia rotate forward and downward, contacting the stigma, and/or the pollen masses dissociate and are deposited on the stigma as if they had sifted downward.

Platanthera aquilonis is a North American diploid species long confused with the tetraploid Icelandic P. hyperborea (Linnaeus) Lindley. Flowers of both species autopollinate, although the details of the mechanisms may differ. The two species differ in column structure and lip and viscidium shape. True P. hyperborea is similar to P. huronensis, and the relationship of these two species needs further study.

(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
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. limosa, P. macrophylla, P. nivea, P. orbiculata, P. peramoena, P. praeclara, P. psycodes, P. purpurascens, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. limosa, P. macrophylla, P. nivea, P. obtusata, P. orbiculata, P. peramoena, P. praeclara, P. psycodes, P. purpurascens, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
Synonyms Orchis obtusata, Habenaria obtusata, Habenaria obtusata var. collectanea
Name authority (Banks ex Pursh) Lindley: Gen. Sp. Orchid. Pl., 284. (1835) Sheviak: Lindleyana 14: 193, figs. 1–5. (1999)
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