Flora of the Canadian Arctic Archipelago
English: One-sided wintergreen, nodding wintergreen,
French: Pyrole unilaterérale.
Pyrolaceae, Wintergreen family.
Published in Bot. Tidsskr. 57: 31. 1961.
Synonymy. Pyrola secunda L. var. obtusata Turcz., Fl. Baical.-Dahur. 2: 213. 1856.
Orthila obtusata (Turcz.) H. Hara, J. Jap. Bot. 20: 328. 1944.
Vegetative morphology. Plants 5–15(–20) cm high; perennial herbs. Only fibrous roots present. Rarely present on herbarium specimens; fine fibrous, black or dark brown roots. Ground level or underground stems horizontal, or vertical; rhizomatous; elongate. Caudex present. Aerial stems erect. Leaves present; mainly basal; alternate; persistent. Stipules absent (much smaller colourless scale leaves present at the base of the petiole). Petioles (3–)5–15 mm long; not winged; glabrous. Leaf blades simple. Leaf blade bases obtuse and rounded. Blades spreading, oblong or ovate or circular, flat, veins pinnate. Blade adaxial surface glabrous. Blade abaxial surface glabrous (and a lighter green than the adaxial surface). Blades not lobed. Blade margins entire or serrulate (minutely), glabrous, with teeth all around the blade (if applicable); apices obtuse, or rounded.
Reproductive morphology. Flowering stems with leaves (scale-like and smaller than the basal leaves). Inflorescences spicate (superficially), or paniculate (in a spike-like panicle with flowers borne to one side); diffuse; linear; 1.5–4 cm long; 5–10 mm wide. Pedicels present; glabrous (0.2–0.5 mm long). Individual spike(s) ascending (main stem), or divergent (individual flowers). Flowers per inflorescence (3–)5–10; small; radially symmetrical (actinomorphic). Sepals conventional; 5; free; 0.6–1 mm long; 1–1.5 mm wide; green, or yellow (cream or sometimes pinkish). Calyx glabrous (margins serrulate). Petals conventional; free; longer than the calyx; 5; green, or white, or yellow, or pink; obovate; unlobed; 3.5–4.5 mm long; 2.2–2.7 mm wide. Stamens 8–10; stamen filaments glabrous. Anthers yellow (or pinkish); short-cylindrical (opening by pores at the ends). Anthers opening with a terminal pore. Anthers 1.4–1.6 mm long (becoming inverted during ontogeny so that the morphological base is apical and the anthers open by pores to shed pollen). Nectaries present (as a disc). Ovary superior; carpels 5; syncarpous (externally furrowed and lobed). Ovaries sub-globose; glabrous. Styles 1; 6–7 mm long (robust); straight; basal portion smooth. Stigmas per ovary 1. Placentation parietal. Ovules per ovary numerous. Fruit stalked; stalk 2–5 mm long; with calyx persisting; dry; a capsule; spherical; brown; 2.5–3.5 mm long; 3.5–4.5 mm wide; glabrous; surface appearing veinless; dehiscent; opening with teeth at the top of the capsule. Seeds numerous; 0.8–1 mm long; surfaces tuberculate.
Chromosome information. 2n = 38.
2n = 38. Böcher (1961b, Greenland); Zhukova and Petrovsky (1971, northeastern Asia); Löve and Löve (1982a, central Canada); Yurtsev and Zhukova (1982, northern Siberia); Dalgaard (1989, western Greenland).
Ploidy levels recorded 2x.
Ecology and habitat. Substrates: snow patches, ridges; dry, moderately well-drained areas; gravel, sand; acidic, or circum-neutral. Gravelly alkaline sand ridges between two large lakes, and silty till beach swales about 400–500 feet above sea-level. Well-drained, south-facing, steep slope of major sand and gravel ridge. In a local Cassiope heath, recently emerged from beneath a snowbed (CAN 527913); rare on warm southfacing cliffs (CAN 17325).
North American distribution. Frequent in moist thickets on continental North America and extending beyond treeline. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic islands: Banks, Victoria.
Northern hemisphere distribution. North American, or Siberian. KaninPechora, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, West Greenland.
General notes. Elven and Murray in Elven et al. (2003) noted that Russian botanists have suggested that there are two taxa that should be treated as full species, O. obtusata (Turcz.) H. Hara and Orthilia secunda (L.) House. Aiken, Elven, and Murray in Elven et al. (2005) note that although northern Siberian plants of the 'obtusata' entity are very different from European material of 'secunda' s.s., in North America they are more difficult to separate.
Erich Haber, who worked extensively on the family (see references), indicated that he has never recognised any infraspecific taxa in Orthilia. His North American experience is that there is considerable morphological variability in growth and leaf form, depending on prevailing ecological conditions. Plants range from quite robust, coriaceous-leaved multi-flowered individuals, when found in temperate, sandy coniferous woods, to very much reduced, depauperate specimens very low in stature, with thin rounded leaves and few flowers, when plants grow in moss in boreal or sheltered tundra habitats. This latter expression is referred to O. secunda subsp. obtusata. A complete range in intermediates occurs, and they can often be found growing close together in more or less the same habitats. These diminutive plants also occur in eastern North American cedar swamps and in poorly drained black spruce forests across the range of the species (Haber, personal communication, March 2002).
Because of the European distinctions, some recognition of taxa is considered appropriate. Thus, Elven and Murray (in Panarctic Flora checklist discussions, 2001, Elven et al. 2003, 2005) suggested recognising subspecies Orthilia secunda (L.) House subsp. secunda and Orthilia secunda (L.) House subsp. obtusata (Turcz.) Böcher.
Illustrations. • Plant in flower. Plant growing from long, thin rhizomes, producing scattered, basal, leathery leaves on short petioles. Vicinity of Holman Island trading post. A.E. Porsild 17324. Aug. 8, 1949. CAN 128042. • Plant in flower. Plant growing from long, thin rhizomes, producing scattered, basal, leathery leaves on short petioles; inflorescences one-sided with small, whitish green flowers and prominent black stigmas hanging downward. Vicinity of Holman Island trading post. A.E. Porsild 17324. Aug. 8, 1949. CAN 128042. • Close-up of infrutescence. Note the fruit are hanging down and the large stigmas have persisted. Vicinity of Holman Island trading post. A.E. Porsild 17324. Aug. 8, 1949. CAN 128042. • 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..