Platanthera flava (L.) Lindl.
Pale Green Orchid
Family - Orchidaceae
Stems - To +/-50cm tall, erect, herbaceous, simple, single or double from the base, glabrous, with vertical ridges formed by decurrent leaf and bract tissue, green.
Leaves - 2-5 per stem, sessile, sheathing, glabrous, entire, narrowly elliptic-lanceolate, acute at apex, the largest with blades to +/-12cm long, +/-2cm broad, dull green above, slightly more shiny below. The midrib deeply impressed adaxially, expressed abaxially.
Inflorescence - Terminal spike to +/-10cm long (tall). Axis glabrous. Each flower subtended by a lanceolate bract. Bracts shorter or longer than the flowers (depending on the variety), green, glabrous, entire.
Flowers - Sessile, green. Floral tube -1cm long, typically twisted, glabrous. Sepals 3, ovate to orbicular, glabrous, entire, to 4mm long, 3mm broad. The lateral two spreading. Petals yellow-green. The spur to 6mm long, slightly curved, glabrous. Lower lip blunt at the apex to very slightly emarginate, to +/-4mm long, 3mm broad, glabrous, with two small basal projections and a tubercle at the base adaxially. Lateral petals rounded to ovate or obovate, spreading, 3-4mm long and broad, glabrous. Column -2mm long and broad, facing forward. Pollinia 1.3mm long. Pollen white.
Flowering - May - September.
Habitat - Mesic bottoms, mesic prairies.
Origin - Native to U.S.
Other info. - This species can be found scattered throughout Missouri but is relatively uncommon. The plant is fairly easy to identify because of its green flowers, which are spurred and have an undivided lower lip.
Photographs taken at Taberville Prairie, MO., 6-7-03.