Giant Rattlesnake Plantain, Green-leaf Rattlesnake-plantain, Rattlesnake Plantain, Western Rattlesnake Plantain

Rattlesnake plantain is an evergreen perennial from 10-45 cm tall. A single, stout stem arises from dark green, basal leaves. Each leaf has a white midrib. The leaves are oval, oblong, or narrowly elliptical in shape, and range from 3 to 10 cm in length. The stem is glandular-tomentose.

The flowers are numerous in a terminal spike from 4-8 cm long with most of the flowers orienting themselves to face one direction. The flowers are dull-white to greenish in color and measure 7-9 mm long. The upper sepal and petals form a hood over the narrow lower lip which has a swollen base and a spreading or recurved tip.

The rattlesnake plantain is found in moist, shady, coniferous forests in humus soil, often amongst clumps of moss. It may be found from low elevations to middle elevations in the mountains.

The rattlesnake plantain is found from Alaska eastward to Nova Scotia. In the east it is found as far south as Maine in the east, and Minnesota in the west. Further west, it is found over much of the mountainous west, and extends as far south as Mexico. It is found in both Oregon and Washington.