Geum geniculatum

Michaux

Fl. Bor.-Amer. 1: 300. 1803.

Common names: Bent avens
Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 65. Mentioned on page 60.

Plants leafy-stemmed. Stems 50–84 cm, sparsely hirsute proximally, hirsute distally. Leaves: basal 14–30 cm, blade interruptedly lyrate-pinnate, major leaflets 1–5, mixed with 2–5 minor ones, terminal leaflet slightly to much larger than major laterals; cauline 4–12 cm, stipules ± free, 7–20 × 4–8 mm, blade pinnate, 3-foliolate, or simple and 3-lobed. Inflorescences 5–15-flowered. Pedicels densely pilose, some hairs septate-glandular. Flowers nodding; epicalyx bractlets 2.5–3 mm; hypanthium green with purple tinge at base to greenish maroon; sepals erect to erect-spreading, 5–8 mm; petals erect, white, pink, or lavender, spatulate-obovate, 5–7 mm, ± equal to sepals, apex rounded, truncate, or shallowly emarginate. Fruiting tori sessile, densely bristly. Fruiting styles geniculate-jointed, proximal segment persistent, 2–4.5 mm, apex hooked, septate-glandular hairs on basal 1/2, distal segment very tardily deciduous, 5–8 mm, pilose except apical 1–2 mm, with some glandular-hairs.


Phenology: Flowering summer.
Habitat: Mountain balds, seeps, stream banks, cliffs, wooded boulder fields
Elevation: 1600–1900 m

Discussion

Of conservation concern.

Geum geniculatum is enigmatic and is currently known from 15 populations in western North Carolina and eastern Tennessee. As a rare plant, it has attracted far less attention than G. radiatum, which is also known from the same region. Although G. geniculatum is not listed federally as endangered or threatened, it is listed as threatened by North Carolina and as endangered by Tennessee.

W. Gajewski (1957) speculated that Geum geniculatum is a hybrid, with one of the parents being G. rivale. K. R. Robertson (1974) pointed out that the nearest locality for G. rivale is in West Virginia and that pollen stainability of G. geniculatum is very high. Geum geniculatum may be of hybrid origin; it cannot be a first-generation hybrid. North American taxonomists have treated it as a valid species.

Selected References

None.

Lower Taxa

None.
... more about "Geum geniculatum"
emarginate +  and truncate +
Joseph R. Rohrer +
Michaux +
compound +  and simple +
opposite +  and alternate +
14 cm140 mm <br />0.14 m <br /> (30 cm300 mm <br />0.3 m <br />) +
greenish maroon +
simple +, 3-foliolate +  and pinnate +
3-lobed +
free +  and distinct +
4 cm40 mm <br />0.04 m <br /> (12 cm120 mm <br />0.12 m <br />) +
Bent avens +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
N.C. +  and Tenn. +
not +  and aggregated +
1600–1900 m +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (4.6 cm46 mm <br />0.046 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
tapered +, ovoid +  and fusiform +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Mountain balds, seeps, stream banks, cliffs, wooded boulder fields +
purple tinge +  and green +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
odd-pinnate +, lyrate-pinnate +, 3-foliolate +  and simple +
opposite +  and alternate +
winter-persistent +
cauline +  and basal +
cordate +, reniform +, orbiculate +, oblanceolate +, obovate +, oblong +, elliptic +  and rhombic +
palmate +  and pinnate +
crenate +, dentate +, laciniate +, 2-7-lobed +, flat +, lobed +, toothed +  and entire +
inferior +  and superior +
clustered +, biseriate +  and superposed +
purple-veined +
0 (?) +  and 4 (?) +
Lavender (?) +, Pink (?) +  and White (?) +
free +  and distinct +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Fl. Bor.-Amer. +
not arillate +
persistent +
free +  and distinct +
erect +  and erect-spreading +
deltate-lanceolate +, deltate-ovate +  and deltate +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
1 +  and 5 +
50 cm500 mm <br />0.5 m <br /> (84 cm840 mm <br />0.84 m <br />) +
palmate +  and pinnate +
0.7 cm7 mm <br />0.007 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
geniculate-jointed +  and entire +
persistent +
distinct +
elongating +
basal +, lateral +, subterminal +  and terminal +
hairy +  and glabrous +
not hooked +  and hooked +
accrescent +
10 cm100 mm <br />0.1 m <br /> (?) +
Acomastylis +, Erythrocoma +, Novosieversia +  and Stylypus +
Geum geniculatum +
species +
slightly to much larger +
inconspicuous +
hemispheric +  and cylindric +
enlarged +
geniculate-jointed +
hairy +  and glabrous +