In the flowers of Goodyera, the lateral petals and dorsal sepal are united into a hood; the lateral sepals are free. The lip, as usual, is lowermost.
The key should work for the majority of specimens, but the unfortunate overlapping of measurements will make exact placement of a few intermediate specimens (extremes of variation and/or hybrids) difficult. However, each of our species has a distinctive leaf patterning and shape that allows recognition of vegetative rosettes in the field, with some experience.
1. Perianth 6–9 mm long; leaf blades with only the midvein outlined above in white or pale green, the largest blades usually 4–6 cm long; plants 20–50 cm tall.
1. Perianth 2.5–5.5 (rarely to 6.5) mm long; leaf blades with white or pale green reticulation ± throughout (sometimes not on the midvein), the largest blades often less than 4 cm long; plants 5–32 cm tall (rarely to 36 cm).
2. Stem with (6–) 7–10 (–14) cauline bracts (or undeveloped leaves); beak of lip (beyond the large pouch) 0.5–0.8 (–1) mm long, about 1/4 the total length of the lip or usually less; inflorescences ± densely flowered on all sides.
2. Stem with 2–5 (–6) cauline bracts; beak of lip 1–2 mm long, about 1/2 the total length of the lip; pouch shallow or deep; inflorescence strongly one-sided or ± loosely flowered on all sides.
3. Lip deeply saccate, the pouch about as deep as long, the beak often strongly turned downward at maturity; plants 5–20 cm tall (usually 10–17 cm); largest leaf blades 0.7–2.5 cm long (usually 1–2 cm); cauline bracts 2–4 (rarely 5, usually 3), the apical 1/3–1/2 of the uppermost one glabrous; perianth (2.5–) 3–4 (–4.5) mm long.
3. Lip shallowly saccate, the pouch longer than deep, the beak horizontal or slightly recurved; plants 13–32 (–36) cm tall (usually 17–25 cm); largest leaf blades 2–5 (–6) cm long (usually 2.2–4 cm); cauline bracts 3–5 (–6), usually 4–5, the uppermost glabrous or, more often, at least sparsely pubescent; perianth 3.5–5.5 (–6) mm long.