User:Louis.Hight/Epipactis gigantea

Epipactis gigantea is a large orchid and the only member of the genus Epipactis that is native to North America. It grows in a range from British Columbia to central Mexico and from the the west coast of the United States to as far east as Texas. It is known by the common names chatterbox, false lady's slipper, giant helleborine, and stream orchid.

Description
Epipactis gigantea is a large, glabrous, rhizomatous orchid that grows between 20 centimeters and one meter in height. Epipactis gigantea is seasonal, flowering between March and June, and it relies on insects and mycorrhizal fungi for reproduction.

Leaves
It has alternating, oval or spear-shaped leaves that are largest near the base of the plant and become smaller towards the tip of the plant. They range in color from green to deep red in populations found in California and Canada. A variety E. epipactis with burgundy foliage is found in California and has been called forma rubrifolia.

Flowers
Between 4 and 18 flowers are distributed over the upper third of the plant. Flowers are sessile with gradient colored petals in various shades of pink to red or burgundy with green tips and dark veining on the petals. The dorsal petal forms a labellum with yellow striations or other markings. The apex of the labellum is cupped and vibrates when perturbed. The three sepals are oval and spear-shaped, slightly cupped, and are mostly green with some pigmentation similar to that of the petals. The sepals also have veining that is darker than the surrounding tissues. Single flowers grow on bracts.

Roots
A few fibrous roots extend from rhizomes.

Distribution
Epipactis gigantea is native to North America and has been documented growing in British Columbia, Arizona, California, Colorado, Idaho, Montana, Nevada, Nebraska, New Mexico, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, Wyoming, and northern Mexico. Populations occur sporadically throughout this range near water.

Habitat
Epipactis gigantea requires moisture and is found in riparian habitats, along streams, seepage wetlands, and in hanging garden habitats. E. gigantea grows at elevations from sea level to 2600 meters. This orchid is frequently found growing in the shade of trees and other plants, but it can also grow in full sun in northern habitats.

E. gigantea is often found in plant communities growing among sedge of the genus Carex, and there is evidence that thick sedge growth prevents herbivory of the orchid.

Pollination
E. gigantea attracts syrphid flies by releasing an aroma mimicking the honeydew of aphids from which the fly larvae feed. The flies pollinate the orchids by moving between plants as they lay their eggs on the flowers.

Mycorrhizal Associations
After the seeds of E. gigantea are fertilized and dispersed, they require mycorrhizal fungi to obtain nutrients and germinate. In addition to requiring mycorrhizal fungi to germinate, adult E. gigantea orchids have been found to associate with fungi of the genus Rhizoctonia which absorb carbon from the orchid and may contribute nitrogen.

Cultivation
Epipactis gigantea, is cultivated as an ornamental plant. The burgundy colored variety found in Sonoma County, California is referred to as Serpentine Night in the horticultural trade.

Conservation
Epipactis gigantea is a rare plant in many parts of its range such as in New Mexico, but it is listed as apparently secure by Nature Serve as of 2016. However, Nature Serve evaluated it as vulnerable, imperiled, and critically imperiled in several states in the United States. Information about the status of E. gigantea is limited, and further evaluation of occurrences, habitat sensitivity, and genetic diversity would be helpful in determining its vulnerability.