Corallorhiza trifida Chatelain
Early Coral-root.
Orchidaceae, orchid family.
Spec. Inaug. Corallorhiza 8: 1760.
Corallorhiza corallorhiza (L.) Karst.
Corallorhiza trifida var. verna (Nutt.) Fern.
Plants saprophytes lacking chlorophyll, with single flowering stems, arising from a coral-like rhizome; less than 15 cm high, or more than 15 cm high; 10–30 cm high. Roots pallid-brown, or red-brown. Caudex absent. Ground-level or under-ground stems horizontal, or vertical and often branched (the ground-level stem system resembles coral; hence the common name); rhizomatous; elongate; 2–5 mm wide. Scales absent. Aerial stems erect; circular or oval in cross-section; with 0 ridges; glabrous, or sparsely hairy (with very few hairs); stem hairs spreading (when present). Leaves absent, or reduced and scale-like near the base of the stem; merely achlorophyllous sheathing scales.
Flowering stems 10–30 cm long; with leaves (reduced to sheathing scales); glabrous. Flowers in inflorescences (that can be compact or elongate). Inflorescences spicate (sometimes appearing so when flowers are subsessile), or racemose; inflorescence dense, or diffuse; inflorescence linear; inflorescence 1–6 cm long; inflorescence 1–2 mm wide; inflorescence not elongating as the fruit matures; inflorescence main axis glabrous. Pedicels glabrous. Pedicels bract leaves 0.9–1.1 mm long; 0.4–0.7 mm wide. Flowers per inflorescence 4–6(–9); medium-sized, 5–15 mm in diameter or length; sessile or subsessile, or borne on a stalk; zygomorphic. Calyx sepals 3; free (but contiguous with the receptacle covering the inferior ovary, so they may look fused in the lower part); 2.5–4 mm long; 1–1.4 mm wide; yellow, or brown; herbaceous; without sessile glands; glabrous. Petals 3; free; brown (in arctic island specimens found to date), or white; with contrasting markings (bluish or purple spots on lip); elliptic (or narrowly oblong, the two lateral petals), or obovate (the apparently lower petal which is modified into a lip, or insect landing platform); unlobed (the lateral petals), or 2-lobed (with two short parallel ridges, the lip petal); 2.5–5 mm long; 1–1.5 mm wide; same length as the calyx. Stamens 1, or 2 (modified as pollen packages (pollinia) attached to a floral column that also bears the stigma and is characteristic of the orchid family); filaments all equal in length. Anthers yellow. Carpels syncarpous; 3. Gynoecia inferior. Styles absent (possibly modified as the petaloid floral column). Stigmas modified into a receptive area near the pollinia and the top of the column. Placentation parietal. Ovules hundreds. Fruit with calyx persisting; a capsule; ellipsoid; not distinctly flattened; dehiscent; splitting to the base into separate segments; 8–13 mm long; 4–7 mm wide; stalked; dry; yellowish, or brown; glabrous, or hairy (sometimes slightly so); surface ribbed. Seeds hundreds, tiny and light; 0.5 mm long (approximately); white, or yellowish; reticulate.
Chromosome information. 2n = 40, 42.
Distribution. Circumpolar, or circumboreal. Range in the Canadian Arctic Archipelago limited. Rare (2 records). Greenland, Canada, United States, Eurasia. Arctic Islands: Baffin. Only found in two locations on Baffin Island, within Auyuittuq National Park Reserve.
Ecology and habitat. Substrates, river terraces, tundra, slopes; moderately well drained; sand, moss.
Notes. This species was first reported from Baffin Island in 1997 by Joyce Gould (Can. Field-Naturalist, 111: 471–472). She found this species at two sites in 1995, in Auyuittuq National Park Reserve, Baffin Island, and prepared a plant voucher from one of them. The specimen was deposited at DAO.
This species is circumboreal (Hultén 1968). Known from the continental Northwest territories north to the treeline (Porsild 1943), the Ungava (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, Polygonum viviparum, Pedicularis flammea, and Carex spp. The second population was found at the base of a colluvial slope, among Salix arctica, the moss Aulocomnium turgidum, and a lichen Stereocaulon sp.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) describes the habitat as "turfy, open places".
Illustrations. • Plant in habitat. Plant from Auyuittuq Park, Baffin Island, Nunavut. Photo by Joyce Gould, 1995. Plant growing with Salix arctica, moss and lichen (Stereocaulon, a white lichen, just visible in the photo at bottom). • Close-up of plant. Photograph taken in the field by Joyce Gould, July 1995. Note spots on lip (petal, white arrow), and three sepals (hence the name "trifida"), attached at the top of the inferior ovary (black arrow). Plant approximately 8 cm tall. • Close-up of plant. Close-up of plants from herbarium specimen DAO 685952. Plants showing both flowers and developing fruit. • Close-up of inflorescence. Close-up of inflorescence of herbarium specimen Note zygomorphic orchid flowers in a raceme, usually of 6 to 9 flowers. Colour faded, but lip of corolla usually spotted. Specimen: N.W.T. Aklavik, R.T. Porsild 6575, 28 June 1931. CAN 17064. • Close-up of fruit. Close-up of dehisced capsules of early Coral-root. Herbarium specimen West Greenland, Qorqut, A.E. Porsild 8785, July 17–18, 1943. CAN 154045. • Herbarium specimen. Specimen collected in Auyuittuq National Park Reserve, Baffin Island, Nunavut, 65°25'30"N, 65°27'04"W. Joyce Gould, 2 July 1995. DAO 685952. • Distribution map.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L.Consaul, R.L. Boles, R. Elven and M.E. LeBlanc. 2001 onwards. Flora of the Canadian Arctic Archipelago. Volume 1. Pteridophytes and Monocotyledons: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 16th March 2001. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Aiken, Dallwitz et al. (1999) should also be cited (see References).
