Thalictrum pubescens

Pursh

Fl. Amer. Sept. 2: 388. 1814, not T. pubescens Schleicher ex de Candolle 1817.

Common names: Tall meadow-rue late meadow-rue meadow-weed muskrat-weed king-of-the-meadow pigamon pubescent
EndemicIllustrated
Synonyms: Thalictrum carolinianum var. subpubescens de Candolle Thalictrum polygamum Muhlenberg ex Sprengel Thalictrum polygamum var. hebecarpum Fernald Thalictrum polygamum var. intermedium B. Boivin Thalictrum polygamum var. pubescens (Pursh) K. C. Davis Thalictrum pubescens var. hebecarpum (Fernald) B. Boivin
Treatment appears in FNA Volume 3.

Stems erect, coarse, 50-300 cm. Leaves basal and cauline; basal and proximal cauline leaves petiolate, distal cauline sessile; petioles and rachises frequently pubescent. Leaf-blade ternately and pinnately decompound; leaflets light to dark green, cordate or nearly orbiculate to ovate or obovate, apically undivided to 2-3 (-5) -lobed or toothed, 11-68 × 5-70 mm, length 0.8-2.6 times width, membranous to firm, margins scarcely revolute, lobe margins entire, surfaces abaxially pubescent to glabrous. Inflorescences racemes or panicles to corymbs, apically ± rounded, many flowered; peduncles and pedicels often pubescent. Flowers unisexual or bisexual (sometimes bisexual with very few stamens); sepals 4 (-6), white to purplish, elliptic-rounded, 2-3.5 mm; filaments ascending, white to purplish, filiform to distinctly clavate, 1.5-7 mm, usually rigid; anthers 0.5-1.5 (-2.1) mm, usually blunt or only slightly apiculate. Achenes numerous, sessile to stipitate; stipe 0.5-1.5 (-2.4) mm; body ellipsoid, 3-5 mm, prominently veined, usually pubescent; beak usually persistent, straight or coiled distally, 0.6-2.5 mm, about 1/2 length of achene body. 2n = 126.


Phenology: Flowering late spring–summer (mid Jun-early Aug).
Habitat: Full sun to deep shade, rich woods, low thickets, swamps, wet meadows, and stream banks
Elevation: 15-1500 m

Distribution

St. Pierre and Miquelon, N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mich., Miss., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va.

Discussion

The ovaries change from white to purplish, becoming light green, then darker green, and finally brown as fruits mature.

Because of the polymorphic nature of Thalictrum pubescens, a proliferation of names for minor morphologic variants has resulted. Field studies (M. Park 1992) have shown that too much morphologic variation occurs within populations to support the recognition of previously described taxa. Plants in New England and northeastern Canada often have a corymbose inflorescence and longer filaments and achene beaks.

This species is often incorrectly treated in floras as T. polygamum Sprengel, an invalid name.

The Iroquois used Thalictrum pubescens medicinally a a wash for head and neck, to stop nosebleeds, and to treat gall (D. E. Moerman 1986).

Selected References

None.

Lower Taxa

None.
... more about "Thalictrum pubescens"
sessile +  and stipitate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
apiculate +  and blunt +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Marilyn M. Park +  and Dennis Festerling Jr. +
cuneate +, truncate +  and cordate +
Leucocoma +  and Undefined sect. Leucocoma +
straight +
persistent +
1/2 length of achene body +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
ellipsoid +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
globose;cylindric +
Tall meadow-rue +, late meadow-rue +, meadow-weed +, muskrat-weed +, king-of-the-meadow +  and pigamon pubescent +
St. Pierre and Miquelon +, N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Ga. +, Ill. +, Ind. +, Ky. +, Maine +, Md. +, Mass. +, Mich. +, Miss. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, S.C. +, Tenn. +, Vt. +, Va. +  and W.Va. +
15-1500 m +
white +  and purplish +
filiform +  and distinctly clavate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
sessile +  and pedicellate +
showy +  and inconspicuous +
bisexual +  and unisexual +
unisexual +
0 cm0 mm <br />0 m <br /> (41 cm410 mm <br />0.41 m <br />) +
stipitate +, sessile +  and aggregate +
falcate;ovoid;obovoid +
Full sun to deep shade, rich woods, low thickets, swamps, wet meadows, and stream banks +
compound +  and simple +
whorled +, opposite +  and alternate +
cauline +  and basal +
light +  and dark green +
1.1 cm11 mm <br />0.011 m <br /> (6.8 cm68 mm <br />0.068 m <br />) +
toothed +, 2-3(-5)-lobed +, undivided +, nearly orbiculate +  and ovate or obovate +
membranous +  and firm +
0.5 cm5 mm <br />0.005 m <br /> (7 cm70 mm <br />0.07 m <br />) +
palmate +  and pinnate +
crenate;entire +
distinct +
conspicuous +
reduced +
Flowering late spring–summer (mid Jun-early Aug). +
1 +  and 16 +
Fl. Amer. Sept. +
not arillate +  and stalked +
white;purplish +
not persistent +
distinct +
elliptic-rounded +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
ribbed +  and veined +
W1 +, Endemic +  and Illustrated +
50 cm500 mm <br />0.5 m <br /> (300 cm3,000 mm <br />3 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
persistent +
abaxially pubescent;glabrous +
Thalictrum carolinianum var. subpubescens +, Thalictrum polygamum +, Thalictrum polygamum var. hebecarpum +, Thalictrum polygamum var. intermedium +, Thalictrum polygamum var. pubescens +  and Thalictrum pubescens var. hebecarpum +
Thalictrum pubescens +
Thalictrum sect. Leucocoma +
species +
herbaceous +  and woody +