Epipactis gigantea

Epipactis gigantea Douglas ex Hook.:
Canada (North America)
Mexico (Mesoamerica)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

B.C.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Okla., Oreg., S.Dak., Tex., Utah, Wash., Wyo.; Mexico; Asia (China, India, s Japan, Tibet).

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Epipactis gigantea grows from southern British Columbia in Canada to northern Mexico and eastwards in the United States to South Dakota and Texas. There has also been at least one collection made in central Mexico (San Luis Potosi).

Distribution: Himalaya Mts., eastwards to Nepal, Sikkim Bhutan; also in China and N. and Central America.

Plants up to 90 cm, sometimes in large clusters. Stem glabrous. Leaves membraneous, flat, ovate to ovate-lanceolate, up to 15 cm long. Inflorescence loose, usually elongated up to 30 cm; rachis minutely pubescent. Lower bracts exceeding flowers. Flowers distant, spreading to pendent. Sepals green, veined with purple on outside, darker brownish-purple on the inside, ovate to ovate-lanceolate, up to 20 mm long. Petals slightly shorter, broadly ovate. Labellum up to 23 mm long, tinged with brownish-purple, with large hypochile and narrowly ovate epichile. Column including anther up to 9 mm long. Ovary sparsely pubescent, after flowering enlarged.

Plants to 1.4 m, essentially glabrous. Leaves 4–14, ovate, ovate-elliptic to narrowly lanceolate, 5–20 × 2–7 cm. Inflorescences lax racemes; floral bracts lanceolate to oblong, 7–127 mm. Flowers 2–32, rather showy; sepals greenish to rose-colored with rose-colored to purple veins; lateral sepals 16–24 × 8–9 mm, apex very oblique; petals pale pink to rose-colored to orange with red or purple veins, broadly ovate to ovate-lanceolate, 13–17 × 6–8 mm; lip marked with red or purple, strongly veined, distinctly 3-lobed, constricted at middle into 2 parts, proximal part papillose, calli red, minute, warty, lateral lobes prominent subtriangular wings, distal part linear-oblanceolate to narrowly spatulate-oblanceolate, grooved to tip, 14–20 mm, calli near base, erect, orange or yellow, winglike; column erect, short, stout, with pair of lateral processes, 5–10 × 3 mm; anther green; pollinia 2 pairs, yellow, soft. Capsules ellipsoid, glabrate or sparsely pubescent, 20–25 mm. 2n = 40.

The tall stems with reddish flowers in the leaf axils make this species one of our most distinctive orchids. It is not easily confused with any other species.

Amesia gigantea (Douglas ex Hooker) A. Nelson & J. F. Macbride; Helleborine gigantea (Douglas ex Hooker) Druce

Wet gravelly and sandy stream shores and bars, may occur in riparian willow, box elder, and river birch woodlands or in chaparral, seepages, marshes, wet cliffs, hot springs; 0--3000m.

Comments: A wide variety of habitats, but all have a constant source of water for the roots (Coleman, 1988).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: This is the most widely distributed orchids of California, with populations nearly throughout the state (Coleman 1988, Hickman 1993). Outside of California, this species appars to occur uncommonly but over a very wide geographic and habitat range. The total number of occurrences are certainly greater than 300.

Epipactis gigantea must have a permanent and constant source of water at the roots. It is easy to cultivate as long as a wet habitat can be provided (Cronquist et al, 1977). In the northern part of its range, it prefers hot springs. One of the known pollinators is the Syrphid fly (Coleman, 1995). E. gigantea seeds are probably dispersed by wind, and possibly by water (Dressler 1981). Seeds of E. gigantea probably require the presence of a mycorrhizal symbiont for germination (Prendergast 1994) In addition to seeds, this species reproduces asexually by underground rhizome, and can sever the connection between the daughter ramet and the parental plant within one season (Thornhill, 1996).

Flowering throughout summer (Mar--Aug).

Fl. Per.: July.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N3 - Vulnerable

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: The range of the Epipactis gigantea is very wide although it is generally not common within that range (except perhaps in California). It can be relatively abundant locally, but some these dense local patches may represent single genetic individuals. The species has an absolute habitat requirement for surface water, which is a threatened habitat in many parts of its range, and it can occur infrequently despite the availability of seemingly suitable habitat. Despite these concerns, on a rangewide basis it is thought to be "apparently secure" (G4) given the large number of existing populations---many without known threats---over its wide range.

Environmental Specificity: Moderate to broad.

Comments: Requires water but beyond that it occurs in a wide variety of habitats. Coleman (1988) noted that it is found in deserts, including Death Valley, on cliffs overlooking the ocean, and in the mountains below 7,500 feet elevation in California and that it shows a wide tolerance of soil pH.

Global Short Term Trend: Decline of 10-30%

Comments: The general trend is one of decline due principally to habitat loss. The loss and modification of riparian areas, seeps, and springs has led to local decline or extirpation of many populations.

Global Long Term Trend: Relatively stable to decline of 50%

Comments:

Degree of Threat: Very high - medium

Comments: The main threat is loss of suitable habitat that is caused by water development projects or any activity that lowers the water table or disturbs the habitat. Rocchio et al. (2006) estimates the primary threats as being (in order of importance): recreation, exotic species, water development, livestock grazing, urban development, timber harvest, and utility line maintenance.

In Idaho and Wyoming populations have been extirpated or reduced in size due to impacts from the recreational use of hot springs. In New Mexico populations have also been extirpated due to water developments. Livestock grazing has detrimentally impacted some populations. In the Rocky Mountain states Rocchio et al. (2006) noted that 7 of the 41 populations known there were definitively UNthreatened. From this, we speculate that a high percentage of populations face at least some of these (possibly interacting) threats (scope=High). The overall degree of immediacy of the various threats to populations rangewide is unknown.

Site scale conservation efforts are likely to be effective in mitigating threats in most cases except where large-scale impacts such as groundwater withdrawl is occurring (Rocchio et al. 2006).

Biological Research Needs: The effect of invasive weed species and water pollution on Epipactis gigantea is necessary. Commercial scale cultivation practices should be explored. This orchid is relatively easy to cultivate and collection from the wild should not be necessary.

Comments: Epipactis gigantea is used as an ornamental only. E. gigantea is not used as a medicinal herb although it is used for ceremonial purposes by some Native American tribes. Cypripedium calceolus var. pubescens (syn. C. parviflorum var. pubescens) is used medicinally in Europe and North America but because of its endangered status some herbalists recommend using the roots of stream orchid or helleborine (Epipactis helleborine), which has the same purported effects. There is no indication that E. gigantea can be substituted for E. helleborine.

Prices for this species were found as follows: While not normally available at local garden centers the plant is apparently not too hard to acquire e.g. garden outlets on the web. The price for a reasonable sized division is between $6- $12.