Geum rossii
(synonym of Geum rossii var. depressum)
Geum triflorum
Ross' avens
old man's beard, old-man's whiskers, prairie smoke, three-flower avens, three-sisters, torchflower
4–28 cm, glabrous or downy, hairs to 1 mm, sometimes septate-glandular.
10–45 cm, downy to pilose, hairs 0.1–3 mm, sometimes septate-glandular.
basal 3–13 cm, blade pinnate to interruptedly pinnate, major leaflets 13–26, alternating with 0–14 minor ones, terminal leaflet slightly larger than major laterals;
cauline 0.7–2 cm, stipules adnate to leaf, indistinguishable from pair of lobes, blade bractlike, not resembling basal, alternate, simple, pinnatifid to 3-fid.
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.
1–3(–4)-flowered.
(1–)3–5(–7)-flowered.
woolly, sometimes glandular.
densely woolly, sometimes glandular.
erect;
epicalyx bractlets 1.5–7 mm;
hypanthium green, slightly purple-tinged to strongly purple;
sepals erect to erect-spreading, 3–10 mm;
petals spreading, yellow, obovate to nearly orbiculate, 5–12(–17) mm, longer than sepals, apex broadly rounded to irregularly emarginate.
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.
sessile, glabrous.
sessile, densely puberulent.
wholly persistent, not geniculate-jointed, 2–5(–10) mm, apex not hooked, glabrous throughout or pilose only at base.
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.
= 56.
Geum rossii
Geum triflorum
The variability accommodated here in Geum rossii was distributed by earlier monographers such as P. A. Rydberg (1913b) and F. Bolle (1933) among a half dozen species. W. Gajewski (1957) reduced them to two species, G. rossii and G. turbinatum; most recent taxonomists have recognized the two taxa as subspecies or varieties of a single species. The large geographic discontinuity between the Rocky Mountain and arctic ranges makes it easy for those wishing to follow this tradition. No one morphologic character or combination of characters neatly separates the arctic plants from those of the Rockies.
Where their ranges overlap in Alaska, Geum rossii hybridizes with G. calthifolium to form sterile plants known as G. ×macranthum (Kearney ex Rydberg) B. Boivin; see discussion under 4. G. schofieldii.
(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.)
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, 
PNW Herbaria 
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, 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
