Thalictrum occidentale |
Thalictrum debile |
|
---|---|---|
western meadow-rue |
southern meadow-rue |
|
Roots | yellow to medium brown or black, thin, fibrous. |
brownish, fusiform-tuberous with dried ribs. |
Stems | erect, 30-100(-120) dm, glabrous, often from well-developed rhizomes. |
reclining, branched and flexible proximally, 10-40 cm, glabrous. |
Leaves | blade 3-4x-ternately compound; leaflets orbiculate to obovate-cuneate or cordate, apically 3-lobed, 10-30 mm wide, lobe margins coarsely crenate, surfaces glabrous to glandular. |
blade: leaflets ovate or obovate to reniform or orbiculate, apically shallowly to deeply 3-7-lobed, rarely undivided, 4-15 mm wide, surfaces glabrous. |
Inflorescences | terminal (some flowers in axils of distal leaves), panicles, rather open, many flowered. |
terminal and axillary, panicles, elongate, few flowered. |
Flowers | sepals whitish or greenish or purplish tinged, ovate, 3.5-4.4 mm in staminate flowers, 1.5-2 mm in pistillate flowers; filaments purplish, 4-10 mm; anthers 1.5-4 mm, long-apiculate; stigma often purplish. |
sepals whitish, lanceolate to obovate, 1.5-2.7 mm; filaments colored, not white, 1.5-2 mm; anthers 1.7-2.5 mm, mucronate; stigma color unknown. |
Achenes | 6-9, spreading to reflexed, short-stipitate; stipe 0.4-1.2 mm; body fusiform, not laterally compressed, (4-)6-9(-10) mm, tapering at both ends, glandular, strongly 3-veined on each side, veins not anastomosing; beak 3-4.5(-6) mm. |
1-6, not reflexed, nearly sessile; stipe 0.1-0.3 mm; body oblong to elliptic-lanceolate, not compressed, 3-3.7 × 0.7-1.2 mm, glabrous, prominently 6-8-veined, veins not anastomosing; beak 1.3-2 mm. |
Thalictrum occidentale |
Thalictrum debile |
|
Phenology | Flowering early summer-mid summer (Jun–Aug). | Flowering in early spring (Mar–Apr). |
Habitat | Open woods, meadows, and copses | Rich, rocky, limestone woods, often in wet, alluvial soil |
Elevation | 200-3400 m (700-11200 ft) | 50-300 m (200-1000 ft) |
Distribution |
AK; CA; CO; ID; MT; ND; NV; OR; UT; WA; WY; AB; BC; SK; YT
|
AL; GA; MS |
Discussion | Thalictrum occidentale is similar to T. confine and T. venulosum; thorough field studies are needed to determine whether or not they should be maintained as separate species. Thalictrum occidentale can usually be distinguished by its reflexed achenes. Plants of northern British Columbia, sometimes called Thalictrum occidentale var. breitungii (B. Boivin) Brayshaw, appear to be intermediate between T. occidentale and T. venulosum (T. C. Brayshaw, pers. comm.); achenes are ascending, ± compressed, and beaks rather short (2-4 mm) (T. C. Brayshaw 1989). Some of the Native Americans used Thalictrum occidentale medicinally for headaches, eye trouble, and sore legs, to loosen phlem, and to improve blood circulation (D. E. Moerman 1986). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Thalictrum debile is closely related to T. arkansanum and T. texanum. The distinctions among the three species should be further studied. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Ranunculaceae > Thalictrum > sect. Heterogamia | Ranunculaceae > Thalictrum > sect. Heterogamia |
Sibling taxa | ||
Synonyms | T. occidentale var. macounii, T. occidentale var. palousense | |
Name authority | A. Gray: Proc. Amer. Acad. Arts 8: 372. (1873) | Buckley: Amer. J. Sci. Arts 45: 175. (1843) |
Web links |
|