Flora of the Canadian Arctic Archipelago
English: Early coral-root, northern coral-root,
French: Corallorhize trifide.
Orchidaceae, Orchid family.
Published in Spec. Inaug. Corallorhiza 8. 1760.
Synonymy. Ophrys corallorhiza L., Sp. Pl. 945. 1753.
Vegetative morphology. Plants 10–15(–30) cm high; perennial herbs; not caespitose. Only fibrous roots present. Roots pallid-brown, or red-brown. Ground level or underground stems horizontal, or vertical (the ground-level stem system resembles coral; hence the common name); rhizomatous; elongate; 2–5 mm wide. Ground level or underground stems scales absent. Aerial stems erect. Leaves absent or leaf teeth (or reduced and scale-like near the base of the stem); merely achlorophyllous sheathing scales.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves (reduced to sheathing scales). Flowers in inflorescences (that can be compact or elongate). Inflorescences racemose (appearing spike-like when the flowers are sub-sessile); dense, or diffuse; linear; 3–6 cm long (more usually 8–15 cm long in southern plants); 1–2(–3) mm wide; not elongating as the fruit matures. Inflorescences main axis glabrous. Pedicels absent, or present; glabrous. Flowers per inflorescence (3–)4–6(–9) (as many as 18 inconspicuous flowers in southern plants); medium-sized; bilaterally symmetrical (zygomorphic). Sepals conventional; 3; free (spreading, contiguous with the receptacle covering the inferior ovary, so they may look fused in the lower part); 1–1.4 mm long; 2.5–4(–7) mm wide; green, or yellow (or brownish, lanceolate, 1 veined, often strongly recurved); herbaceous. Calyx without sessile glands; glabrous. Petals conventional; free (arching over and clasping the column); same length as the calyx; 3; brown (in the only arctic island specimens found to date), or white (usually light yellow-green, often spotted with purple); with contrasting markings (bluish or purple spots on lip); lanceolate (or narrowly oblong, the two lateral petals), or obovate (the other petal which is modified into a lip, or insect landing platform); unlobed (the lateral petals), or slightly lobed or undulating (the lip petal with two short parallel ridges); 2.5–5 mm long (lip petal 2.5–4 mm long × 1.5–3 mm wide, thin, with 2 small lateral lobes or teeth, middle lobe oblong, often somewhat dilated near the apex, with 2 distinct basal lamellae; column curved towards the lip, yellowish green, sometimes spotted purple basally, with a shallow adaxial channel 2–3.3 mm long); 1–1.5 mm wide. Stamens present (as pollinia); 1, or 2 (modified as yellow pollen packages (pollinia) attached to a floral column that also bears the stigma and is characteristic of the orchid family). Ovary inferior; carpels 3; syncarpous. Styles absent (possibly modified as the petaloid floral column). Placentation parietal. Ovules per ovary hundreds. Fruit stalked; with calyx persisting; dry; a capsule; ellipsoid; yellowish, or brown; (4.5–)8–13(–15) mm long; 4–7 mm wide; glabrous, or hairy (sometimes slightly so); surface venation ribbed; not distinctly flattened; dehiscent; splitting to the base into separate segments. Seeds hundreds, tiny and light; 0.5 mm long (approximately); white, or yellowish; surfaces reticulate.
Chromosome information. 2n = 38–42.
2n = 38-42. Hagerup (1941b, northern Europe); Sørensen and Westergaard in Löve and Löve (1948, Greenland); Löve (1954b, Iceland); Löve and Löve (1956, Iceland); Löve (1981d, central Canada); Jørgensen et al. (1958, Greenland); Sorsa (1963b, Finland, 2n = about 42); Laane (1967, Norway); Krogulevich (1976, northern Siberia); Averyanov (1979, northwestern Russia 2n = 38); Dalgaard (1988, western Greenland). Several more southern counts.
Ploidy levels recorded 4x.
Ecology and habitat. Substrates: river terraces, tundra, slopes; moderately well-drained areas; sand, moss.
North American distribution. Only found in two locations on Baffin Island, within Auyuittuq National Park. Alaska, Yukon, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Rare (2 records). Arctic islands: Baffin.
Northern hemisphere distribution. Circumpolar, or circumboreal (mainly boreal). Northern Iceland, Northern Fennoscandian, KaninPechora, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok (?), Kharaulakh, YanaKolyma, West Chukotka, South Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. This orchid is a pinkish brown colour, lacking chlorophyll. It is a saprophyte and gets its nutrients from mycorrhiza on the roots. Because of the complex relationship between the orchid and the environment in which it is growing, this species is almost impossible to transplant and should be left growing where it is found.
This species was first reported from Baffin Island in 1997 by Joyce Gould (Can. Field-Naturalist, 111: 471–472). She found this species in Auyuittuq National Park, Baffin Island, at two sites in 1995, and prepared a plant voucher from one of them. The specimen was deposited at DAO.
This species is circumboreal (Hultén 1968) and is known from continental Northwest territories north to treeline (Porsild 1943), Ungava (northern Quebec) (Cayouette 1984), and western Greenland (Hultén 1968). It was not an altogether unexpected find on southeastern Baffin Island (Gould 1997).
Both of the populations found by Gould (1997) were in fluvial deposits. One population was found on the east side of a river, "at the base of an end moraine and of a fluvial terrace just south of a small tributary, in a habitat dominated by Arctic willow (Salix arctica) and moss (Pohlia drummondii), and with Arctagrostis latifolia, Pyrola grandiflora, Poa arctica, Persicaria vivipara, Pedicularis flammea, and Carex species". The second population was found at the base of a colluvial slope, among Salix arctica, the moss Aulocomnium turgidum, and a species of the lichen Stereocaulon. Hultén (1968, p. 329) describes its habitat as "wet places, woods, bogs." Scoggan (1978, p. 528) notes the habitat as "bogs, thickets and woods", while in the Northwest territories, Porsild and Cody (1980, p. 213) describe the habitat as "turfy, open places".
Magrath and Freudenstein (2002) noted that Corallorhiza trifida is largely autogamous, although a syrphid fly (Syrphus cinctellus) was reported as a pollinator (Silen 1906). Various floral morphs exist, some with weak geographic corrections; they do not appear to warrant recognition.
Illustrations. • Habitat. Pinkish plant lacking chlorophyll. Green leaves are Salix arctica. Nunavut, Baffin Island, Auyuittuq Park. 1995. DAO 685952. Photograph by Joyce Gould. • Close-up of plant. Note lip with spots (white arrow) and three sepals (hence the name "trifida") attached at the top of the inferior ovary (black arrow). Plant approximately 8 cm tall. Nunavut, Baffin Island, Auyuittuq National Park. 1995. DAO 685952. Photograph by Joyce Gould. • Herbarium specimen. Specimen collected in Auyuittuq National Park Reserve, Baffin Island, 65°25'30"N, 65°27'04"W. 2 July, 1995. Joyce Gould. DAO 685952. • Close-up of plant. Plants showing both flowers and developing fruit. Nunavut, Baffin Island, Auyuittuq National Park. DAO 685952. • Close-up of inflorescence. Raceme of zygomorphic flowers. Colour is faded; corolla lip is usually spotted. N.W.T., Aklavik. 28 June, 1931. R.T. Porsild 6575. CAN 17064. • Arctic Island Distribution.
This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.
Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.
Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa..