This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Low herbs, with small bulbs and mostly solitary flowers on bracted scapes, the solitary leaf linear, hidden at first in the upper bract, protruding after flowering. Sepals and petals about equal, connivent and hooded above, coherent below. Lip dilated and recurved-spreading at the apex, crested on the face with straight somewhat fleshy hairs, slightly gibbous at the base. Column adherent to the lip below, linear, narrowly winged and dilated at the summit. Anther operculate, of 2 approximated sacs incumbent upon the column; pollinia 4, 2 in each sac, powdery-granular. Capsule erect, ellipsoid, strongly angled. [Dedicated to the nymph Arethusa.]
Two known species, the following, the generic type, occurring in North America, the other in Japan.
Arethusa bulbosa L. Sp. PI. 950. 1753.
Scape glabrous, 5'-10' high, bearing 1-3 loose sheathing bracts. Leaf linear, many-nerved, becoming 4'-6' long; flower solitary (rarely 2), arising from between a pair of small unequal scales, rose-purple, 1'-2' high; sepals and petals linear to elliptic, obtuse, arched over the column; lip usually drooping beneath the sepals and petals, the apex broad, rounded, often fringed or toothed, variegated with purplish blotches, bearded, crested down the face in three white hairy ridges; capsule about 1' long, ellipsoid, strongly 6-ribbed, rarely maturing.
In bogs, Newfoundland to Ontario and Minnesota, South Carolina and Indiana. May-June.