Geum macrophyllum |
Geum triflorum |
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benoîte à grandes feuilles, bigleaf avens, large-leaf avens |
old man's beard, old-man's whiskers, prairie smoke, three-flower avens, three-sisters, torchflower |
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Habit | Plants leafy-stemmed. | Plants subscapose. | ||||||||
Stems | 30–110 cm, puberulent and hirsute or sparsely hirsute. |
10–45 cm, downy to pilose, hairs 0.1–3 mm, sometimes septate-glandular. |
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Leaves | basal 10–45 cm, blade interruptedly lyrate-pinnate, major leaflets 5–9, alternating with 4–15 minor ones, terminal leaflet usually much larger than major laterals; cauline 2–12 cm, stipules ± free, 7–23 × 3–12 mm, blade lyrate-pinnate, pinnate, 3-foliolate, or simple and 3-lobed. |
basal 4–30 cm, blade interruptedly pinnate, major leaflets 10–18, alternating with 6–16 minor ones gradually increasing in size distally, terminal leaflet slightly larger than major laterals; cauline 1–5 cm, stipules adnate to leaf, indistinguishable from leaflets/lobes, blade bractlike, not resembling basal, opposite, pinnate-pinnatifid. |
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Inflorescences | 3–16-flowered. |
(1–)3–5(–7)-flowered. |
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Pedicels | densely puberulent, sometimes with scattered longer hairs, sometimes stipitate-glandular. |
densely woolly, sometimes glandular. |
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Flowers | erect; epicalyx bractlets often absent, 0.5–2 mm; hypanthium green; sepals erect-spreading but soon reflexed, 2.5–5.5 mm; petals spreading, yellow, obovate, broadly elliptic, or suborbiculate, 3.5–7 mm, longer than sepals, apex rounded. |
nodding, erect in fruit; epicalyx bractlets 6–15 mm; hypanthium maroon, purple, or greenish mottled with purple, may turn pale brown in fruit; sepals erect, 7–14 mm; petals erect, cream to yellowish suffused with pink or purple, or purple-veined, elliptic, 7–13 mm, shorter to longer than sepals, apex rounded to obtuse. |
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Fruiting tori | sessile or on less than 1 mm stipes, puberulent. |
sessile, densely puberulent. |
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Fruiting styles | geniculate-jointed, proximal segment persistent, 2.5–6 mm, apex hooked, sparsely to densely stipitate-glandular, distal segment deciduous, 1–2 mm, pilose in basal 1/3, hairs much longer than diam. of style. |
wholly persistent or distal 3–7 mm tardily deciduous, not or inconspicuously geniculate-jointed, 15–70 mm, apex not or occasionally ± hooked, pilose to apex or nearly so. |
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Geum macrophyllum |
Geum triflorum |
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Distribution |
AK; AZ; CA; CO; ID; MA; ME; MI; MN; MT; ND; NE; NH; NM; NV; NY; OR; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NS; NT; NU; ON; PE; QC; SK; YT; Eurasia
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AZ; CA; CO; IA; ID; IL; MI; MN; MT; ND; NM; NV; NY; OR; SD; UT; WA; WI; WY; AB; BC; MB; NT; ON; SK; YT; Mexico
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Discussion | Varieties 2 (2 in the flora). Characters useful in recognizing specimens of Geum macrophyllum are yellow petals, epicalyx bractlets often absent, proximal style segment sparsely to densely stipitate-glandular, and fruiting receptacles puberulent. Across its broad North American range from Alaska to California and Nova Scotia, G. macrophyllum exhibits considerable variation. Based largely on the shape of the terminal leaflet of the basal leaves and the degree of dissection and shape of the divisions of the distal cauline leaves, P. A. Rydberg (1913b) distinguished three species within the range of variation treated here as one species. Basal leaves of G. macrophyllum in the strict sense (var. macrophyllum in this treatment) have relatively large reniform to rounded terminal leaflets and the distal cauline leaves are three-cleft into rhombic or cuneate lobes. The basal-leaf terminal leaflets of G. perincisum (= var. perincisum) are only slightly larger than the laterals and are deeply lobed into rhombic-obovate segments; the distal cauline leaves are dissected into oblanceolate divisions. Both basal and cauline leaves of G. oregonense (= var. perincisum) are intermediate between those of G. macrophyllum and G. perincisum. W. Gajewski (1955) crossed all three taxa under discussion and examined leaf morphology and cytology of the F1 and F2 hybrids. He concluded that they were distinct but not yet completely separated species. Fairly well correlated with the more dissected leaves of G. oregonense and G. perincisum is the presence of minute stalked glands on the pedicels. The treatment here follows H. M. Raup (1931) in recognizing two varieties of G. macrophyllum based more on pedicel glandularity than leaf morphology. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). At the beginning of the twentieth century, E. L. Greene described over a dozen species belonging to the Geum triflorum complex based on differences in leaf form and indument, the relative length and shape of the epicalyx bractlets and sepals, and petal length and shape. Most of these species were quickly reduced to synonymy by other botanists. When specimens are examined from across the continent, most of the characters used to separate species in the G. triflorum complex show nearly continuous variation. It seems best to treat these variants as belonging to one species. Whether and how to classify the variation within the species will remain controversial. Some character expressions correlate reasonably well with dividing the species into two varieties, as was first proposed by N. C. Fassett (1928). Variety triflorum occurs east of the Rocky Mountains and is typical of the grasslands covering the northern Great Plains; it also is the variety found in the mountains of Arizona and New Mexico. Variety ciliatum is common throughout the rest of the Rocky Mountains, the Sierra Nevada, and Cascade Range. Intermediate specimens occur here and there, particularly in Alberta and British Columbia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 66. | FNA vol. 9, p. 62. | ||||||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum | Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum | ||||||||
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Subordinate taxa | ||||||||||
Synonyms | Erythrocoma triflora, Sieversia triflora | |||||||||
Name authority | Willdenow: Enum. Pl., 557. (1809) | Pursh: Fl. Amer. Sept. 2: 736. (1813) | ||||||||
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