Rich. (rein orchis, fringed orchid)
with the flowering stems from a fascicle of fleshy, sometimes tuberlike roots.
Flowering stems glabrous, with racemes or spikes toward the tip. Leaves 1–9,
green, alternate on the flowering stems (basal elsewhere) and grading into the
bracts subtending the flowers, sessile, lanceolate to elliptic, glabrous.
Sepals all similar, ovate to broadly elliptic in Missouri species, usually
somewhat pouchlike, the upper sepal forming a shallow hood over the column.
Lateral petals mostly arching upward and inward, overlapping under the upper
sepal. Lip variously entire to lobed or fringed, spreading and somewhat
downward arching, with a usually long (as long as or longer than the rest of
the lip) spur produced from the base and positioned more or less parallel to
the ovary or somewhat pendant. Column with 1 stamen, the anther with 2 pollen
sacs separated by a thin or broad connective, each arm of which bears a viscidium
(a sticky structure along the arm). Staminodes lacking. Capsules ascending,
5–25 mm long, elliptic in outline, strongly ribbed. Forty species, North
America, Europe, Asia.
Platanthera is one of the largest of the several segregates of Habenaria,
the largest native to North America. In the broad sense that is still accepted
by a minority of botanists, Habenaria is a worldwide genus of nearly 700
species. In the strict sense, as accepted here, true Habenaria is a
primarily tropical genus of about 600 species that is represented on the
Coastal Plain of the southeastern United States by only 4 species. The main
separations between these genera reside in details of floral morphology. See Coeloglossum
for the treatment of another segregate of Habenaria that occurs in Missouri.