Calopogon tuberosus (L.) Britton, Sterns & Poggenb.

Grass Pink

Calopogon tuberosus plant

Family - Orchidaceae

Stems - From an undivided corm. Stems to +/-65cm tall, erect, herbaceous, terete, green, glabrous, simple, single from the base.

Leaves - One well developed leaf per stem. Other leaves reduced and scale-like. Large leaf linear, acute, entire, +/-20cm long, 1cm broad, glabrous, sheathing at the base, with expressed veins below which create a somewhat pleated appearance.

Calopogon tuberosus leaf

Inflorescence - Terminal raceme to +20cm tall (long). Axis slightly zig-zag, glabrous. Each flower subtended by a subulate scale. Scales acute, to +/-5mm long. Flower sessile.

Flowers - Floral tube to +/-1cm long, glabrous, green to purplish. Sepals and petals pink to purplish, glabrous. Sepals acute, to +2cm long, +1cm broad, the upper 2 somewhat oblique. Lower sepal oblong to narrowly elliptic. Upper lip of the corolla hinged, deflexed, with white, yellow and orange hairs at the apex, to -2cm broad, broadest at the apex, -2cm long, with two small basal lobes. Lobes acute, 2-3mm long. Column arched and protruding from the rest of the flower, to 2cm long, stout, winged near the apex and 7-8mm broad, darker than the rest of the flower near the apex. Lateral petals to 2.2cm long, oblong-elliptic.

Calopogon tuberosus flower

Flowering - June - July.

Habitat - Fens.

Origin - Native to U.S.

Other info. - This amazing orchid can only be found in a few eastern Ozark counties. The plant is fen obligate which greatly restricts its range in Missouri. Another species, C. oklahomensis D.H. Goldman, is found in mesic prairies habitats. This latter species is found in a handful of western counties in Missouri.
Both of these species are bee pollinated. The brilliantly colored upper lip of the corolla (which appears to a bee as stamens covered in pollen) is hinged and falls downward when a bee lands on it. This rubs the back of the bee into the column of the corolla. If the bee has visited another flower already, the present flower will be pollinated.

Photographs taken near Stegal Mountain, Shannon County, MO., 6-21-03 and 6-13-05.