Geum canadense |
Geum urbanum |
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benoîte du Canada, white avens |
benoîte commune, clover-root, colewort, herb-bennet, town avens, wood avens |
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Habit | Plants leafy-stemmed. | Plants leafy-stemmed. |
Stems | 30–100 cm, glabrate to downy, hairs to 1.5 mm, sometimes glandular. |
25–85 cm, puberulent and sparsely hirsute. |
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. |
basal 12–25 cm, blade strongly lyrate-pinnate to pinnate, major leaflets 1–9, sometimes alternating with minor ones, terminal leaflet slightly to much larger than major laterals; cauline 4–15 cm, stipules ± free, 10–40 × 5–35 mm, blade pinnate, 3-foliolate, or simple and 3-lobed. |
Inflorescences | 3–15-flowered. |
3–18-flowered. |
Pedicels | densely hairy, hairs of varying lengths, few long stiff ones, sometimes glandular. |
puberulent, less densely hirsute, eglandular. |
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. |
erect; epicalyx bractlets 0.5–2 mm; hypanthium green; sepals spreading but soon reflexed, 2–5 mm; petals spreading, yellow, suborbiculate, elliptic, or obovate, 2–6 mm, shorter to longer than sepals, apex rounded. |
Fruiting tori | sessile, densely bristly, hairs 1–2.3 mm. |
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. |
geniculate-jointed, proximal segment persistent, 3–7 mm, apex hooked, glabrous, distal segment deciduous, 1–1.5 mm, glabrous or with short hairs, hairs shorter than diam. of style. |
2n | = 42. |
= 42. |
Geum canadense |
Geum urbanum |
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Phenology | Flowering spring–summer. | Flowering summer. |
Habitat | Lowlands and upland forests, meadows, along streams, thickets, bottomland hardwoods, swamps | Waste places, hedgerows, gardens, edge of sidewalks, disturbed woods, along roads and trails in mesic woods |
Elevation | 0–600 m (0–2000 ft) | 0–1400 m (0–4600 ft) |
Distribution |
AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY; MB; NB; NS; ON; PE; QC; Mexico (Chiapas)
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ID; IL; MA; MI; NY; OH; OR; PA; RI; UT; VT; WA; WI; NB; ON; QC; Eurasia; n Africa [Introduced in North America]
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Discussion | 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. 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Specimens from Chicago, Illinois, and Cambridge, Massachusetts, indicate that Geum urbanum has been present in North America for at least 100 years; herbarium specimens are scarce. The species seems to be spreading in ruderal habitats of the northeastern United States and adjacent Canada. The plants have the habit and foliage of G. canadense and G. virginianum, with stipules as large as or even larger than those of the latter; the petals are bright yellow versus white or cream, and the distal segments of the styles are glabrous or nearly so versus partially pilose. Geum urbanum is often found growing near G. canadense, and the two occasionally form hybrids; G. ×catlingii J.-P. Bernard & R. Gauthier is known from New Brunswick, Ontario, Quebec, and Michigan. Less common is G. ×macneillii J.-P. Bernard & R. Gauthier [G. laciniatum × G. urbanum], known from Quebec. Both hybrids closely resemble G. urbanum in vegetative form, with little hint of their other parent; it is likely that hybrid plants often go undetected. Most herbarium specimens of these hybrids were collected along with their parental species at the same locality. The hybrids are often robust, apparently showing hybrid vigor. Unlike G. urbanum, they have cream petals and heads with mostly sterile ovaries. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 68. | FNA vol. 9, p. 70. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum | Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum |
Sibling taxa | ||
Synonyms | G. camporum, G. canadense var. brevipes, G. canadense var. camporum, G. canadense var. grimesii, G. canadense var. texanum | |
Name authority | Jacquin: Hort. Bot. Vindob. 2: 82, plate 175. 1772–1773 | Linnaeus: Sp. Pl. 1: 501. (1753) |
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