Platanthera grandiflora
Platanthera integrilabia
greater purple fringe bog-orchid, greater purple fringe orchid
monkeyface, white fringeless orchid
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.
2(–3), spreading to ascending, on basal portion of stem, abruptly reduced to bracts distally;
blade lanceolate to elliptic, 12–23 × 1–3.2 cm.
lax to rather dense.
rather lax.
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, white;
lateral sepals reflexed;
petals oblong, margins entire;
lip porrect, spatulate to lance-spatulate, without basal thickening, 10–15 × 2.5–4 mm, margins slightly lacerate to subentire;
spur slenderly cylindric, scarcely clavate, 35–60 mm;
rostellum lobes directed forward, spreading, angular;
rostellum lobes slenderly curving forward, slightly spreading, angular-elongate, long;
pollinaria with stalks curved forward;
pollinia remaining enclosed in anther sacs;
viscidia orbiculate;
ovary slender, ca.16–22 mm.
= 42.
Platanthera grandiflora
Platanthera integrilabia
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.
The description of Platanthera integrilabia is based on a limited sample and is likely too restrictive.
Flowers of this species are nocturnally sweet-scented. The vegetative habit is distinctive, with leaves restricted to the base of the stem and a relatively few-flowered inflorescence borne atop a tall bracted scape. In addition to the normal tuberoid, roots often enlarge distally to form bud-bearing tuberoids at a marked distance from the parent stem, giving rise to diffuse clonal colonies.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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