The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

greater purple fringe bog-orchid, greater purple fringe orchid

great lakes rein orchid, green bog orchid, Huron green orchid, Lake Huron bog green orchid, northern green bog-orchid

Habit Plants 27–120 cm. Plants 10–100 cm or more.
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.

few–several, ascending, scattered along stem, gradually reduced to bracts distally;

blade oblong to linear-lanceolate, 5–30 × 0.6–7 cm.

Spikes

lax to rather dense.

very lax to very 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, 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.

= 84.

Platanthera grandiflora

Platanthera huronensis

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 Wet meadows, tundra, marshes, fens, stream banks, shores, ditches, seeping slopes, roadsides
Elevation 0–1800 m (0–5900 ft) 0–3300 m (0–10800 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
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
[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.)

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. 565. FNA vol. 26.
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. 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 grandiflora, Habenaria fimbriata, Habenaria psycodes var. grandiflora Orchis huronensis, Habenaria hyperborea var. huronensis, Habenaria ×media, Limnorchis media, P. hyperborea var. huronensis, P. ×media
Name authority (Bigelow) Lindley: Gen. Sp. Orchid. Pl., 294. (1835) (Nuttall) Lindley: Gen. Sp. Orchid. Pl., 288. (1835)
Web links