Geum triflorum
Geum rivale
old man's beard, old-man's whiskers, prairie smoke, three-flower avens, three-sisters, torchflower
benoîte des ruisseaux, chocolate-root, purple avens, water avens
10–45 cm, downy to pilose, hairs 0.1–3 mm, sometimes septate-glandular.
30–85 cm, sparsely downy to scattered-hirsute proximally, downy distally.
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.
basal 6–40 cm, blade interruptedly pinnate, major leaflets 5–7, mixed with 7–14 minor ones, terminal leaflet slightly larger than major laterals;
cauline 2–10 cm, stipules ± free, 7–18 × 5–9 mm, blade pinnate to 3-foliolate.
(1–)3–5(–7)-flowered.
2–8-flowered.
densely woolly, sometimes glandular.
densely downy, some hairs glandular.
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.
nodding;
epicalyx bractlets 2–4 mm;
hypanthium greenish maroon to maroon;
sepals erect, 7–10 mm;
petals erect, yellow, suffused with purple and purple-veined, spatulate-obovate, 8–10 mm, ± equal to sepals, apex rounded, truncate, or shallowly emarginate.
sessile, densely puberulent.
on 4–10 mm stipes, densely bristly.
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.
geniculate-jointed, proximal segment persistent, 5–9 mm, apex hooked, stipitate-glandular, bristles on basal 1/2, distal segment deciduous, 3–4.5 mm, pilose except apical 1 mm.
= 42.
Geum triflorum
Geum rivale
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.)
Geum rivale forms hybrids with three other species of the genus in North America: G. ×aurantiacum Fries ex Scheutz [G. aleppicum × G. rivale] is reported from Alberta, Ontario, Montana, and New York; G. ×pervale B. Boivin [G. macrophyllum var. perincisum × G. rivale] is known from Alberta, Ontario, Quebec, and Saskatchewan; and G. ×pulchrum Fernald [G. macrophyllum var. macrophyllum × G. rivale] is reported from Ontario, Quebec, Idaho, New Hampshire, and Vermont. The hybrids generally have the habit and foliage of G. rivale but exhibit shallower hypanthia, spreading sepals, and pure yellow, clawed, obovate to suborbiculate petals. The glandular hairs on the pedicels usually lack the dark tips seen in G. rivale. Given that the morphologic differences among the three named hybrids are vague, suspected hybrid specimens are best determined while in the field where collectors can note the proximity of the hybrids to their supposed parental species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Basal leaves with larger leaflets toothed or cleft less than 1/2 their lengths; fruiting styles persistent, 28–70 mm. | var. triflorum |
1. Basal leaves with larger leaflets cleft more than 1/2 their lengths; fruiting styles: proximal segments persistent, 15–40 mm, distal segments tardily deciduous, 3–7 mm. | var. ciliatum |
- Local floras:
BC, 
OR, 
WA - Local Web sites:
CalFlora, CalPhotos, 
Flora NW, 
IL Wildflowers, 
MI Flora, 
MN Wildflowers, 
PNW Herbaria, 
SW CO Wildflowers, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras: BC, WA
- Local Web sites: Flora NW,
Go Botany, IL Wildflowers, 
MD Biodiversity, MI Flora, MN Wildflowers, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
