Platanthera clavellata (Michaux) Luer

Club-spur orchid, small green wood orchid

The specific epithet clavellata is the Latin meaning "club-shaped," in reference to the clubbed (clavate!) spur of this species.

DESCRIPTION: Plant glabrous, arising from a cluster of fleshy, thickened roots, 10-33 cm tall. Leaf 1, oblanceolate to obovate, attached just below the middle of the stem (although sometimes appearing basal), 6.5-18 cm long and 1.4-5 cm wide, ascending, stem with 1-2 reduced to linear-lanceolate bracts above the leaf. Inflorescence a loose raceme, 5-15 flowered, the flowers only incompletely resupinate and thus appearing "askew"; flowers yellowish-green to green to whitish-green, each flower subtended by a small, lance-linear, acuminate bract. Sepals ovate, concave, 2-5 mm long and 1.5-3 mm wide, colored as flowers; dorsal sepal connivent with petals over the column, lateral sepals slightly spreading. Petals similar to sepals, connivent with dorsal sepal over the column, colored as flowers. Labellum oblong to quadrate with the apex shallowly three-lobed, 3-6 mm long and 1-3 mm wide, colored as flowers, base of labellum with a strongly clubbed (occasionally appearing scrotiform at the tip) nectar spur projecting behind, about 10 mm long.

Platanthera clavellata could perhaps be confused with P.obtusata, as both species are found in swampy or boggy areas and have only one leaf. The two are easily separated by the shape of the labellum: the labellum is narrow-lanceolate and acute in P.obtusata, but is oblong and tridentate in P. clavellata.

Typically found in sphagnous, boggy areas, such as the margin of sandy lakes, sphagnous swales or meadows, or Sphagnum bogs.

July 10-August 5.

Platanthera clavellata is self-pollinating, with the pollen germinating in the clinandria and growing down into the stigma (Catling 1983a). This was actually first described by Asa Gray. Despite this, insects must at least occasionally visit the plants, as Fred Case has collected a hybrid between P. clavellata and P. blephariglottis, which he has named P. X vossii Case (Case 1983).

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