Platanthera grandiflora |
Platanthera obtusata |
|
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greater purple fringe bog-orchid, greater purple fringe orchid |
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 |
|
Habit | Plants 27–120 cm. | Plants 5.5–35 cm. |
Leaves | 2–6, wide-spreading and recurved to somewhat ascending, scattered along stem, gradually reduced to bracts distally; blade lanceolate, elliptic, oblong-elliptic, or oblong-obovate, 13–24 × 2.5–9 cm. |
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. |
Spikes | lax to rather dense. |
lax. |
Flowers | resupinate, showy, lavender- to rose-purple, rarely white; lateral sepals spreading to somewhat reflexed; petals ovate, oblong, elliptic-oblong, or oblong-obovate, margins crenate to dentate-lacerate, sometimes nearly entire; lip descending to somewhat porrect, deeply 3-lobed, without basal thickening, 10–25 × 14–26 mm, distal margins of lobes fringed, usually deeply, lateral lobes sometimes perpendicular to middle lobe, lateral lobes cuneate, often broadly so, middle lobe broadly cuneate-flabellate, often emarginate to 2-fid; spur clavate, 15–35 mm; rostellum lobes directed forward, spreading, angular; pollinaria nearly straight; pollinia remaining enclosed in anther sacs; viscidia orbiculate; ovary slender to stout, 12–25 mm. |
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. |
2n | = 42. |
= 42, 63 (American, as Habenaria obtusata), 126 (Eurasian, as Habenaria obtusata). |
Platanthera grandiflora |
Platanthera obtusata |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Alluvial and swamp forests, stream banks, seeping slopes, marshes, sphagnum bog forests, mesic wooded slopes, old fields | Mesic to wet coniferous forest, forested fens, sphagnum bogs, stream banks, tundra, moist roadsides |
Elevation | 0–1800 m (0–5900 ft) | 0–3500 m (0–11500 ft) |
Distribution |
CT; MA; MD; ME; NC; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WV; NB; NF; NS; ON; PE; QC
|
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]
|
Discussion | Platanthera grandiflora is known to hybridize with P. lacera in the northeasternmost portion of its range, where the species bloom simultaneously. The name P. ×keenanii P. M. Brown has recently been proposed for these hybrids, but the complex synonymy of this group dictates that types be checked for possible priority. See the discussion under P. lacera. A few specimens also suggest very rare hybridization with P. psycodes (W. P. Stoutamire 1974). Rare white-flowered plants may be separated from 23. Platanthera leucophaea by the orientation of the pollinia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 26, p. 565. | FNA vol. 26, p. 556. |
Parent taxa | Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera | Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera |
Sibling taxa | ||
Synonyms | Orchis grandiflora, Habenaria fimbriata, Habenaria psycodes var. grandiflora | Orchis obtusata, Habenaria obtusata, Habenaria obtusata var. collectanea |
Name authority | (Bigelow) Lindley: Gen. Sp. Orchid. Pl., 294. (1835) | (Banks ex Pursh) Lindley: Gen. Sp. Orchid. Pl., 284. (1835) |
Web links |