Burke: Platanthera orbiculata

	Platanthera orbiculata
	large round-leaf orchid
Habit	Glabrous, scapose perennial 2-6 dm. tall.
Leaves	Leaves usually 2, opposite and basal, subsessile, spreading and usually lying on the ground, fleshy, suborbicular to oblong-elliptic, 6-16 cm. long and 3-14 cm. wide, rounded; scape usually with 1-3 small bracts about midlength.
Flowers	Inflorescence a loose raceme with floral bracts 7-12 mm. long, green, linear to lanceolate; flowers 5-25, pale to deep greenish-white or yellowish, with pedicles 3-7 mm. long; upper sepal erect, reniform to broadly ovate, 4-8 mm. long and broad, rounded, entire to shallowly lobed near the tip; lower sepals obliquely triangular-ovate, slightly reflexed, 8-13 mm. long; petals paler than the sepals, often nearly white, narrower and shorter than the lower sepals, rounded, reflexed; lip white, strap-shaped, pendant, slightly upturned at the tip, 2-4 mm. broad and 10-20 mm. long; spur club-shaped, strongly curved, 15-25 mm. long, pale and translucent near the base, the tip greenish; stamens and style fused to form a column 4-5 mm. long with 2 lateral projections 3-5 mm. long.

	Platanthera orbiculata
Flowering time	June-August
Habitat	Moist, mossy forests.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east across Canada and the northern U.S. to the Atlantic Coast, also in the southeastern U.S. [WildflowerSearch map] [BONAP county map]
Origin	Native
Conservation status	Not of concern
Sibling taxa	P. aquilonis, P. chorisiana, P. dilatata, P. elegans, P. elongata, P. ephemerantha, P. huronensis, P. obtusata, P. sparsiflora, P. stricta, P. transversa, P. unalascensis
Web links	Local floras: BC, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Platanthera orbiculata

large round-leaf orchid

Habit

Glabrous, scapose perennial 2-6 dm. tall.

Leaves

Leaves usually 2, opposite and basal, subsessile, spreading and usually lying on the ground, fleshy, suborbicular to oblong-elliptic, 6-16 cm. long and 3-14 cm. wide, rounded;

scape usually with 1-3 small bracts about midlength.

Flowers

Inflorescence a loose raceme with floral bracts 7-12 mm. long, green, linear to lanceolate;

flowers 5-25, pale to deep greenish-white or yellowish, with pedicles 3-7 mm. long; upper sepal erect, reniform to broadly ovate, 4-8 mm. long and broad, rounded, entire to shallowly lobed near the tip; lower sepals obliquely triangular-ovate, slightly reflexed, 8-13 mm. long;

petals paler than the sepals, often nearly white, narrower and shorter than the lower sepals, rounded, reflexed;

lip white, strap-shaped, pendant, slightly upturned at the tip, 2-4 mm. broad and 10-20 mm. long;

spur club-shaped, strongly curved, 15-25 mm. long, pale and translucent near the base, the tip greenish;

stamens and style fused to form a column 4-5 mm. long with 2 lateral projections 3-5 mm. long.

Platanthera orbiculata

Flowering time

June-August

Habitat

Moist, mossy forests.

Distribution

Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east across Canada and the northern U.S. to the Atlantic Coast, also in the southeastern U.S.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa