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alpine avens, Ross' avens, slender stem avens

heartleaf avens, spring avens

Habit Plants subscapose. Plants leafy-stemmed.
Stems

4–28 cm, glabrous or downy, hairs to 1 mm, sometimes septate-glandular.

20–70 cm, pilose or sparsely pilose, hairs septate.

Leaves

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 4–27 cm, blade simple or pinnate, leaflets 3–11, terminal leaflet larger;

cauline 2–7 cm, stipules ± free, 8–25 × 7–12 mm, blade pinnate to 3-foliolate.

Inflorescences

1–3(–4)-flowered.

3–13-flowered.

Pedicels

woolly, sometimes glandular.

glandular-downy, becoming glabrate in fruit.

Flowers

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 absent;

hypanthium green;

sepals reflexed, 1–3 mm;

petals spreading, yellow to cream, oblong to elliptic, sometimes obovate, 1–2 mm, equal to or shorter than sepals, apex rounded.

Fruiting tori

sessile, glabrous.

on 3–7 mm stipes, glabrous.

Fruiting styles

wholly persistent, not geniculate-jointed, 2–5(–10) mm, apex not hooked, glabrous throughout or pilose only at base.

geniculate-jointed, proximal segment persistent, 1.5–3 mm, apex hooked, nearly glabrous except for few septate-glandular hairs, distal segment deciduous, 0.7–1 mm, nearly glabrous except for short hairs.

2n

= 56.

= 42.

Geum rossii

Geum vernum

Phenology Flowering summer. Flowering spring.
Habitat Alpine and arctic tundra, rocky slopes, often in gravelly or peaty soil Moist woods, disturbed moist areas, flood plains, openings
Elevation 0–4000 m (0–13100 ft) 0–600 m (0–2000 ft)
Distribution
from FNA
AK; AZ; CO; ID; MT; NM; NV; OR; UT; WA; WY; BC; NT; NU; YT; Greenland; e Asia (Russian Far East)
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; DC; DE; GA; IA; IL; IN; KS; KY; MA; MD; MI; MO; NC; NE; NJ; NY; OH; OK; PA; TN; VA; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
Discussion

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 vernum is distinctive and is recognized by its early flowering, minute petals, lack of epicalyx bractlets, and heads of achenes soon elevated well beyond the recurved hypanthia and sepals. Recently, it has been expanding its range northward and has been collected with increasing frequency in southern Ontario, Massachusetts, Michigan, New York, and Wisconsin. No specimens could be located to confirm reports of G. vernum from Mississippi or Texas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 63. FNA vol. 9, p. 70.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum Rosaceae > subfam. Rosoideae > tribe Colurieae > Geum
Sibling taxa
G. aleppicum, G. calthifolium, G. canadense, G. geniculatum, G. glaciale, G. laciniatum, G. macrophyllum, G. peckii, G. radiatum, G. rivale, G. schofieldii, G. triflorum, G. urbanum, G. vernum, G. virginianum
G. aleppicum, G. calthifolium, G. canadense, G. geniculatum, G. glaciale, G. laciniatum, G. macrophyllum, G. peckii, G. radiatum, G. rivale, G. rossii, G. schofieldii, G. triflorum, G. urbanum, G. virginianum
Synonyms Sieversia rossii, Acomastylis rossii, G. rossii var. depressum, G. rossii var. turbinatum, G. turbinatum, S. gracilipes Stylypus vernus
Name authority (R. Brown) Seringe: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 2: 553. (1825) (Rafinesque) Torrey & A. Gray: Fl. N. Amer. 1: 422. (1840)
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