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white fringe orchid, white-fringe bog-orchid

greater purple fringe bog-orchid, greater purple fringe orchid

Habit Plants 8–110 cm. Plants 27–120 cm.
Leaves

2–several, spreading to ascending, scattered along stem, rather abruptly to gradually reduced distally;

blade linear-lanceolate, ovate-lanceolate, elliptic-lanceolate, 5–35 × 1–5 cm.

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.

Spikes

dense to rather lax.

lax to rather dense.

Flowers

resupinate, showy, white;

lateral sepals reflexed;

petals linear to oblanceolate, apex fringed to nearly entire;

lip reflexed to porrect, without basal thickening, ovate-oblong to oblong-elliptic, rarely quadrangular-suborbiculate, margin fringed;

spur essentially cylindric, slender;

rostellum lobes curving forward, slightly spreading, angular-elongate;

pollinaria with stalks curved forward;

pollinia remaining enclosed in anther sacs;

viscidia elliptic-suborbiculate to orbiculate;

ovary slender, 10–28 mm.

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.

2n

= 42.

Platanthera blephariglottis

Platanthera grandiflora

Phenology Flowering Jun–Aug.
Habitat Alluvial and swamp forests, stream banks, seeping slopes, marshes, sphagnum bog forests, mesic wooded slopes, old fields
Elevation 0–1800 m (0–5900 ft)
Distribution
from USDA
e North America
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; MA; MD; ME; NC; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WV; NB; NF; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Key
1. Spur less than 26 mm, to 1.25 times length of ovary.
var. blephariglottis
1. Spur at least 30 mm, commonly about 2 times length of ovary.
var. conspicua
Source FNA vol. 26, p. 567. FNA vol. 26, p. 565.
Parent taxa Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera
Sibling taxa
P. aquilonis, 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
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, 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
Subordinate taxa
P. blephariglottis var. blephariglottis, P. blephariglottis var. conspicua
Synonyms Orchis blephariglottis, Habenaria blephariglottis Orchis grandiflora, Habenaria fimbriata, Habenaria psycodes var. grandiflora
Name authority (Willdenow) Lindley: Gen. Sp. Orchid. Pl., 291. (1835) (Bigelow) Lindley: Gen. Sp. Orchid. Pl., 294. (1835)
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