Platanthera hyperborea (L.) Lindley

Leafy green orchid, northern green orchid, northern bog-orchid

The specific epithet hyperborea is derived from the Greek meaning "above the North," in reference to the far northern habitat where this orchid was first collected (Iceland).

DESCRIPTION: Plant glabrous, arising from a cluster of fleshy, thickened roots, 10-90+ cm tall. Leaves 2-5, lanceolate to oblanceolate to elliptical, gradually reduced to linear-lanceolate bracts higher up on the stem, 5-30 cm long and 1-6 cm wide, ascending. Inflorescence a loose or dense raceme, 10-60 flowered; flowers green, pale greenish-white, or yellowish-green, each flower subtended by a lance-linear, acuminate bract. Lateral sepals lanceolate to ovate-lanceolate, 4-8 mm long and 1.5-3 mm wide, spreading to reflexed, colored as flowers; dorsal sepal broadly ovate, 3-6 mm long and 2-4 mm wide, connivent with petals over the column, colored as flowers. Petals lanceolate to ovate-lanceolate, falcate, 3-7 mm long and 1-2 mm wide, connivent with dorsal sepal over the column, colored as flowers. Labellum lanceolate to triangular-lanceolate, 3-8 mm long and 1-3 mm wide, colored as flowers, base of labellum with a +/- clubbed nectar spur projecting behind, 2-6 mm long.

Platanthera hyperborea is easily confused with P. dilatata. This problem is exacerbated by the fact that the two hybridize freely, and produce intermediate offspring. Specimens that are not easily assigned to either one species or the other are probably introgressants, and may be impossible to determine. Representative specimens of the two taxa can be separated by the shape of the labellum, which is strongly dilated at the base in P. dilatata, and only weakly so in P. hyperborea.

Platanthera hyperborea will grow in almost any moist to wet, open to semi-open habitat. It grows in acidic Sphagnum bogs, and in highly neutral fens. It is frequently found in northern Wisconsin in roadside ditches.

June 15-July 25.

While some varieties or populations of this species are pollinated by bumblebees and moths (Catling & Catling 1989), many (if not all) are also autogamous (Catling 1983a). The photo above on the left illustrates autogamy in this species. Here, a partially open flower is being self-pollinated. The pollinia, which have fallen out the clinandria, are bent over at the caudicles, and are contacting the stigma.

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