Platanthera flava

(Linnaeus) Lindley

Gen. Sp. Orchid. Pl., 293. 1835.

IllustratedEndemic
Basionym: Orchis flava Linnaeus Sp. Pl. 2: 942. 1753
Synonyms: Habenaria flava (Linnaeus) R. Brown Perularia scutellata (Nuttall) Small
Treatment appears in FNA Volume 26. Treatment on page 563. Mentioned on page 552, 564.

Plants 13–65 cm. Leaves (1–)2–3(–4), spreading to ascending, gradually to rather abruptly reduced to bracts distally; blade lanceolate to elliptic-oblong, 5–35 × 1–7 cm. Spikes lax to dense. Flowers resupinate, inconspicuous, yellowish green; lateral sepals porrect to reflexed; petals oblong-orbiculate to ovate, apex somewhat crenulate; lip descending to commonly reflexed, 2–6 × 1.8–5 mm, base auriculate, with prominent central tubercle, distal margin entire to slightly crenulate; spur cylindric to strongly clavate, 4–8(–11) mm, apex rarely 2-lobed; rostellum lobes mostly parallel to slightly diverging, directed downward, minute, obscure; pollinia remaining enclosed in anther sacs; viscidia mostly quadrangular, oblong-quadrangular, orbiculate, or broadly asymmetric, commonly canaliculate to nearly cylindric and difficult to assess; ovary rather slender to stout, mostly 8–10 × 2 mm.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Lip (excluding auricles) subquadrangular, suborbiculate, or broadly ovate, often emarginate; inflorescences usually rather lax, slender (this enhanced by floral bracts mostly shorter than flowers). Platanthera flava var. flava
1 Lip (excluding auricles) oblong, usually obtuse, (rarely triangular, acute); inflorescences usually rather dense, stout (this emphasized by floral bracts usually long, often greatly exceeding flowers). Platanthera flava var. herbiola