Geum rossii
Geum virginianum
alpine avens, Ross' avens, slender stem avens
cream avens, cream or Virginia or pale avens, cream-color avens
4–28 cm, glabrous or downy, hairs to 1 mm, sometimes septate-glandular.
25–110 cm, puberulent and hirsute to densely hirsute, some hairs 2–2.5 mm.
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 12–25 cm, blade simple or pinnate, major leaflets 3–5, plus 0–4 minor basal ones, terminal leaflet slightly larger than major laterals;
cauline 4–15(–23) cm, stipules ± free, 11–48 × 6–35 mm, blade 3-foliolate or simple and 3-lobed to unlobed.
1–3(–4)-flowered.
3–14-flowered.
woolly, sometimes glandular.
puberulent, sometimes with scattered hairs, eglandular.
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.
erect;
epicalyx bractlets 1–1.5 mm;
hypanthium green;
sepals spreading but soon reflexed, 3–6 mm;
petals spreading, cream, oblong to elliptic, (1.5–)2–3.5 mm, shorter than sepals, apex rounded.
sessile, glabrous.
sessile, densely bristly, hairs 1–2.3 mm.
wholly persistent, not geniculate-jointed, 2–5(–10) mm, apex not hooked, glabrous throughout or pilose only at base.
geniculate-jointed, proximal segment persistent, (3–)4.5–7 mm, apex hooked, glabrate, distal segment deciduous, 1–2 mm, pilose in basal 1/2, hairs much longer than diam. of style.
= 56.
Geum rossii
Geum virginianum
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.)
Geum virginianum has been confused nomenclaturally with G. laciniatum. B. L. Robinson and M. L. Fernald (1908) and J. K. Small (1933) misapplied the name G. virginianum to the species correctly named G. laciniatum, and they used the names G. flavum (Robinson and Fernald) and G. hirsutum (Small) for what is correctly named G. virginianum. Much of what is named G. virginianum in older herbarium collections is actually G. laciniatum.
In habit and leaf form, Geum virginianum is similar to G. canadense. Geum virginianum differs in having cream petals shorter than the sepals (versus white and usually equal to or longer), the largest stipules of the cauline leaves 20–48 × 10–35 mm (versus smaller), and the stems hirsute to densely hirsute (versus glabrate to downy with only scattered longer hairs). The variability within G. canadense is so great that for some specimens it is difficult to determine whether they belong to G. canadense or G. virginianum.
L. A. Raynor (1952) believed Geum virginianum to be an F1 hybrid between G. aleppicum and G. canadense. K. R. Robertson (1974) acknowledged that some herbarium specimens assignable to G. virginianum from the area where G. aleppicum and G. canadense are sympatric have mostly aborted pollen and may represent natural hybrids. He pointed out that farther south, where G. aleppicum is absent, specimens of G. virginianum appear fully fertile and seem to represent a valid species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- 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
Go Botany
IL Wildflowers
MD Biodiversity
MI Flora
MO Plants
