Thalictrum pubescens |
Thalictrum heliophilum |
|
---|---|---|
King-of-the-meadow, late meadow-rue, meadow-weed, muskrat-weed, pigamon pubescent, tall meadow-rue |
cathedral bluff meadow-rue |
|
Roots | fibrous. |
|
Stems | erect, coarse, 50-300 cm. |
14-50 cm, arising singly or in dense clusters of 2-3 from short, horizontal, fibrous-rooted rhizomes. |
Leaves | 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. |
blade ternately compound, cauline blades gradually reduced upward, distalmost 2-ternate; leaflets broadly obovate, apically 3-toothed, otherwise undivided, 5-8 × 4-5 mm, leathery, surfaces glabrous, glaucous. |
Inflorescences | racemes or panicles to corymbs, apically ± rounded, many flowered; peduncles and pedicels often pubescent. |
terminal, panicles, many flowered. |
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. |
sepals 4, color unknown, lanceolate to ovate, 2-3 mm; filaments brownish, 2-3 mm; anthers 2-3 mm, apiculate; stigma color unknown. |
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. |
4-5(-6), not reflexed, nearly sessile; stipe 0.1-0.2 mm; body oblique-obovate, strongly laterally compressed, 4-5 mm, glabrous, glaucous, prominently 3-veined on each side, veins converging near apex, rarely branched or sinuous, not anastomosing-reticulate; beak ca. 1.5 mm. |
2n | = 126. |
|
Thalictrum pubescens |
Thalictrum heliophilum |
|
Phenology | Flowering late spring–summer (mid Jun-early Aug). | Flowering summer–summer (Jun–Aug). |
Habitat | Full sun to deep shade, rich woods, low thickets, swamps, wet meadows, and stream banks | Decomposing shale of Green River Formation |
Elevation | 15-1500 m (0-4900 ft) | 2500 m (8200 ft) |
Distribution |
AL; AR; CT; DC; DE; GA; IL; IN; KY; MA; MD; ME; MI; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; NB; NF; NS; ON; PE; QC; SPM
|
CO |
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). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. In a genus of primarily mesophytic plants, Thalictrum heliophilum is notable for its relatively xeric habitat. Known only from Garfield and Rio Blanco counties, northwestern Colorado, it is similar to the widespread T. fendleri; it may be distinguished by its smaller, leathery, glaucous leaflets and fewer achenes. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Ranunculaceae > Thalictrum > sect. Leucocoma | Ranunculaceae > Thalictrum > sect. Heterogamia |
Sibling taxa | ||
Synonyms | T. carolinianum var. subpubescens, T. polygamum, T. polygamum var. hebecarpum, T. polygamum var. intermedium, T. polygamum var. pubescens, T. pubescens var. hebecarpum | |
Name authority | Pursh: Fl. Amer. Sept. 2: 388. 1814, not T. pubescens Schleicher ex de Candolle (1817) | Wilken & DeMott: Brittonia 35: 156. (1983) |
Web links |