Polygonum viviparum Linnaeus, Sp. Pl. 1: 360. 1753; Bistorta vivipara subsp. macounii (Small ex J. M. Macoun) Soják; Persicaria vivipara (Linnaeus) Ronse Decraene; Polygonum viviparum var. macounii (Small ex J. M. Macoun) Hultén
Plants (2-)8-30(-45) cm; rhizomes sometimes contorted. Stems 1-2(-3). Leaves: ocrea brown, cylindric, 4-22(-27) mm, margins strongly oblique, glabrous; petiole attached to sheath 6-20(-45) mm, unwinged distally, 5-110(-200) mm; blade linear to lanceolate or oblong-ovate, 1-8(-10) × 0.5-1.7(-2.3) cm, base cuneate to rounded or cordate, often asymmetric, margins entire, usually revolute, not wavy, apex obtuse to acute, abaxial face pubescent with whitish or brownish hairs, glaucous, adaxial face glabrous, not glaucous; cauline leaves 2-4, petiolate proximally, sessile distally, gradually reduced distally, blade linear-lanceolate to linear. Inflorescences 1, narrowly elongate-cylindric, (15-)20-90 × 4-10 mm, usually bearing pink to brown or purple pyriform bulblets proximally and sterile flowers distally; peduncle 1-5 cm. Pedicels ascending or spreading, (1-)2-5 mm. Flowers 1-2 per ocreate fascicle; perianth greenish proximally, usually white or pink distally, rarely red; tepals obovate, 2.1-4 mm, apex obtuse to acute; stamens included or exserted, some or all often poorly developed; anthers reddish to purple. Achenes rarely produced, dark brown, 2.2-3.3 × 0.9-1.5 mm, dull, granular. 2n = 96, 120.
Flowering Jun-Sep. Moist to wet spruce or mixed woods along shorelines, moist subalpine woods and meadows, alpine meadows, heaths, nutrient-rich sites; 0-4000 m; Greenland; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr. (Labr.), N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Ariz., Colo., Idaho, Maine, Mich., Minn., Mont., Nev., N.H., N.Mex., Oreg., S.Dak., Utah, Vt., Wash., Wyo.; Europe; Asia.
Bistorta vivipara is highly variable morphologically and cytologically. Robust plants with large leaves, compact spikes, and persistent bulblets have been named subsp. macounii. Abortion of stamens, production of bulblets, and the rarity of fruits suggest that reproduction is largely asexual; fruits and seedlings are produced rarely (N. Söyrinki 1989). B. Jonsell and T. Karlsson (2000+, vol. 1) summarized chromosome numbers that include 2n = 66, ca. 77, ca. 80, 88, 99, ca. 100, 110, 120, and ca. 132.
A. E. Porsild and W. J. Cody (1980) reported that indigenous peoples of the circumpolar region eat the starchy, slightly astringent rootstocks raw or cooked, and preserve them in seal oil or by freezing. E. Hultén (1968) reported that the rootstocks taste like almonds.
