13. Geum canadense Jacquin, Hort. Bot. Vindob. 2: 82, plate 175. 1772–1773.
White avens, benoîte du Canada
Geum camporum Rydberg; G. canadense var. brevipes Fernald; G. canadense var. camporum (Rydberg) Fernald & Weatherby; G. canadense var. grimesii Fernald & Weatherby; G. canadense var. texanum Fernald & Weatherby
Plants leafy-stemmed. Stems 30–100 cm, glabrate to downy, ˂hairs to 1.5 mm, sometimes glandular˃. Leaves: basal 10–25 cm, blade simple or pinnate, major leaflets 3–5, plus 0–4 minor basal ones, terminal leaflet larger than major laterals; cauline 3–8 cm, stipules ± free, 4–13 × 1–7 mm, blade 3-foliolate or simple and 3-lobed to unlobed. Inflorescences 3–15-flowered. Pedicels densely hairy, ˂hairs of varying lengths, few long stiff ones˃, sometimes glandular. Flowers erect; epicalyx bractlets 0.5–1.5 mm; hypanthium green; sepals spreading but soon reflexed, 3–6 mm; petals spreading, white, obovate to oblong, (3–)4–8 mm, ± equal to or slightly longer than sepals, apex rounded. Fruiting tori sessile, densely bristly, ˂hairs 1–2.3 mm˃. Fruiting styles geniculate-jointed, proximal segment persistent, 2–8 mm, apex hooked, usually glabrous, sometimes sparsely hairy or stipitate-glandular, distal segment deciduous, 1–2 mm, pilose in basal 1/2, ˂hairs much longer than diam. of style˃. 2n = 42.
Varieties and forms have been described in an effort to classify the variation encompassed in Geum canadense. In the eastern half of the United States, it is by far the most common, widespread, and variable of the Geum species. Nearly all writers of recent floras have not found it worthwhile to apply names to the variants. Perhaps the most distinctive and worthy of further consideration are plants from the southwestern corner of the range in Arkansas, Oklahoma, and Texas. These plants, some of which fit Fernald and Weatherby’s description of var. texanum, bloom from late March through May, significantly earlier than the rest of the species, which typically flowers after June first, even in the other southern states.
Flowering spring–summer. Lowlands and upland forests, meadows, along streams, thickets, bottomland hardwoods, swamps; 0–600 m; Man., N.B., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.; Mexico (Chiapas).
Geum canadense hybridizes with G. urbanum (= G. ×catlingii J.-P. Bernard & R. Gauthier); see discussion under 15. G. urbanum.
Geum album J. F. Gmelin is a superfluous name that pertains here.
SELECTED REFERENCE Fernald, M. L. and C. A. Weatherby. 1922. Varieties of Geum canadense. Rhodora 24: 47–50.