2. Platanthera clavellata (Michx.) Luer (green wood orchid)
Pl. 115 d, e; Map 473
Habenaria
clavellata (Michx.) Spreng.
Flowering
stems 10–45 cm long, the flowers 3–15 in a usually dense raceme. Main stem
leaves 1 or 2 (3), the lowest much larger than the upper one(s). Sepals 4–6 mm
long, pale green to pale yellow. Lateral petals 4–5 mm long, ovate to obovate,
the tips pointed, greenish white to pale yellow. Lip 4–6 mm long, oblong, the
tip truncate, the margins somewhat irregular, unlobed but usually with 3 well‑defined,
shallow teeth at the tip, rarely nearly entire, greenish white to light yellow.
Spur 7–12 mm long, strongly curved, club‑shaped at the tip. Column 1 mm
long, yellowish green, the viscidia 0.5 mm apart. 2n=42. July–August.
Uncommon
in southeastern Missouri, in the Ozarks and Crowley’s Ridge (eastern U.S. west to Minnesota and Texas, Canada). Acid seeps and moist, acidic soils along margins of
sinkhole ponds.
The
flowers of P. clavellata are unusual in that they are usually rotated at
a 45‑degree angle from the vertical axis, rather than being totally
resupinate. They also are apparently self‑pollinated throughout much of
the species’ range, by a process in which the pollen masses crumble and fall
onto the stigmatic surfaces.