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greater purple fringe bog-orchid, greater purple fringe orchid

eastern prairie fringe orchid, eastern prairie white fringe bog-orchid, prairie white fringe orchid

Habit Plants 27–120 cm. Plants 32–112 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.

several to many, ascending, scattered along stem, imperceptibly reduced to bracts distally;

blade lanceolate to ovate-lanceolate, usually to 20 × 4 cm.

Spikes

lax to rather dense.

lax to moderately dense.

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, showy, corolla white, calyx green to whitish green;

lateral sepals porrect;

petals obovate to rarely flabellate, apically lacerate;

lip descending to horizontally projecting, deeply 3-lobed, without basal thickening, 14–22 × 15–29 mm, distal margins of lobes deeply incised, fringed, lateral lobes flabellate, usually broad, overlapping middle lobe, middle lobe flabellate, sometimes very broadly, emarginate;

spur slenderly clavate, 28–47 mm;

rostellum lobes nearly parallel, directed downward, short, rounded;

pollinaria geniculate;

pollinia directed forward (column appearing hooded), remaining enclosed in anther sacs;

viscidia orbiculate;

ovary slender, mostly 15–30 mm.

2n

= 42.

= 42.

Platanthera grandiflora

Platanthera leucophaea

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 prairies, marshes, fens, lake shores, old fields
Elevation 0–1800 m (0–5900 ft) 80–300 m (300–1000 ft)
Distribution
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]
from FNA
IA; IL; IN; LA; ME; MI; MO; NE; NJ; NY; OH; OK; VA; WI; ON
[WildflowerSearch map]
[BONAP county map]
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.)

Of conservation concern.

A very rare hybrid with Platanthera psycodes, known only from Ontario, is P. ×reznicekii Catling, Brownell & G. Allen.

See the discussion under 22. Plantanthera praeclara.

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

Source FNA vol. 26, p. 565. FNA vol. 26, p. 566.
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. 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. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, 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 grandiflora, Habenaria fimbriata, Habenaria psycodes var. grandiflora Orchis leucophaea, Habenaria leucophaea
Name authority (Bigelow) Lindley: Gen. Sp. Orchid. Pl., 294. (1835) (Nuttall) Lindley: Gen. Sp. Orchid. Pl., 294. (1835)
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