Oxytropis
Oxytropis riparia
crazyweed, locoweed, oxytrope
oxus locoweed, riparian oxytrope
spreading to ascending, usually pubescent, rarely glabrescent or glabrous.
basally clustered or cauline, alternate, mostly odd-pinnate;
stipules present, sometimes persistent, adnate to petiole, often connate-sheathing;
petiolate, petiole sometimes persistent as marcescent thatch on caudex, rarely as pungent spines;
leaflets 1–45(–70), usually opposite, subopposite, scattered (irregularly spaced), or fasciculate, rarely alternate or verticillate, usually jointed to rachis, blade margins entire, surfaces usually pubescent, sometimes glabrous.
subsessile, 5–15 cm;
stipules foliaceous, light tan or grayish proximally, green distally, well separated on stem, 5–10 mm, sparsely to densely appressed to spreading pilose abaxially, margins ciliate;
leaflets 11–17, alternate to subopposite, blades broadly lanceolate to oblanceolate, 10–38 × 3–12 mm, apex acute or subacute, surfaces sparsely to densely appressed to spreading-pilose abaxially, margins ciliate.
(18–)20–50-flowered, elongate, lax, subsecund.
1–50-flowered, axillary, racemes (sometimes subcapitate);
bract 1;
bracteoles usually absent, rarely 2.
8–15 cm, surpassing leaves, axis 3–20 cm in fruit, sparsely strigose to moderately pilose;
bract linear-lanceolate, sparsely to densely pilose.
papilionaceous;
calyx usually campanulate or cylindric, rarely inflated-urceolate, lobes 5, sometimes inflated and enclosing legumes, usually ruptured by legume;
corolla pink to blue-purple or white to yellowish, 5–25 mm, keel petals shorter than wing petals, tip elongated into porrect beak;
stamens 10, diadelphous;
anthers dorsifixed;
ovary enclosed in staminal sheath;
style glabrous.
purplish, 6–7 mm.
scarcely enlarging in fruit, campanulate, white-strigose;
tube 2–2.5 mm, lobes 1.2–1.5 mm.
legumes, sessile or stipitate, sometimes tumid or bladdery-inflated, straight, oblong to ellipsoid, ovoid, ovoid-ellipsoid, ovoid-oblong, lanceoloid-ovoid, cylindric, or subcylindric, abaxial suture usually rounded, adaxial suture often sulcate, dehiscent apically or throughout, unilocular or bilocular, or partially bilocular by intrusion of adaxial suture, usually pubescent, rarely glabrous.
pendulous, stipitate, stipe 1–2.5 mm, sulcate adaxially, narrowly oblong, 15–20 × 4–5 mm, unilocular, papery, white- and/or black-strigulose.
3–25, light to dark brown or black, somewhat reniform.
= 8.
= 16, 32.
Oxytropis
Oxytropis riparia
Species ca. 300 (22 in the flora).
Separation of Oxytropis from Astragalus has long been argued, and the history of the discussion was outlined by R. C. Barneby (1952b) and S. L. Welsh (1989). The main distinctions lie in the inequilateral leaf bases of Oxytropis (as opposed to equilateral in Astragalus), and the porrect keel petals found in all species of Oxytropis and not in Astragalus. Molecular phylogenetic studies have supported the distinctness of the two genera (M. F. Wojciechowski 2005; A. D. Tekpinar et al. 2016).
Several relatively recent treatments of the taxonomy and nomenclature of Oxytropis differ greatly in their conclusions. Among these are the revision by S. L. Welsh (2001), publications by B. A. Jurtzev (1986, 1993b), J. M. Gillett et al. (2007), and the Pan-Arctic Flora (http://panarcticflora.org/).
At least some species of Oxytropis are highly toxic to grazing animals, due to the presence of swainsonine in their tissues (L. F. James et al. 1989).
Oxytropis revoluta Ledebour was attributed to Alaska by E. Hultén (1968) but has not yet been found in the flora area. It occurs in Russian islands immediately west of the United States/Russia border.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Oxytropis riparia evidently was first discovered on ranches near Waterloo and Twin Bridges, in the valleys of the Jefferson and Ruby rivers in Madison County, Montana. The species is currently spreading and is to be expected at widely distributed locations throughout much of the American West. Plants at the Seedskadee National Wildlife Refuge, Wyoming, are eaten by sage grouse; they seem to prefer the flower buds but eat all parts of the plant.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants usually caulescent (1+ internodes apparent); legumes subsessile or stipitate, pendulous or spreading-declined. | → 2 |
2. Leaflets 11–17, blades broadly lanceolate to oblanceolate, apices acute or subacute; racemes 20–40-flowered; introduced, Idaho, Montana, North Dakota, Utah, Wyoming. | O. riparia |
2. Leaflets (9–)15–41, blades ovate, lanceolate, or lanceolate-oblong, apices acute to obtuse; racemes (2–)4–25[–30+]-flowered; native, widespread in w North America. | O. deflexa |
1. Plants acaulescent or appearing acaulescent (internodes concealed by leaf bases); legumes sessile, subsessile, or stipitate, erect, spreading, or spreading-declined. | → 3 |
3. Legumes spreading-declined. | O. deflexa |
3. Legumes erect or spreading. | → 4 |
4. Base of herb sheathed with reddish, purplish, or purplish brown stipules. | → 5 |
5. Corollas yellowish. | O. maydelliana |
5. Corollas purplish. | → 6 |
6. Racemes 1–3-flowered; legumes stipitate, reclining on ground at maturity, usually at least 3 times longer than wide. | O. kokrinensis |
6. Racemes 5–8-flowered; legumes sessile, held aloft at maturity, to 3 times longer than wide. | O. kobukensis |
4. Base of herb with light tan or grayish stipules, sometimes black in O. campestris). | → 7 |
7. Leaflets usually 1 or 3, rarely 5, decurrent or obscurely articulated with rachis. | O. mertensiana |
7. Leaflets (1–)5–45(–70), jointed to rachis. | → 8 |
8. Plants glandular-viscid (especially stipules and calyces); bracts glabrous, except margins ciliate. | O. borealis |
8. Plants not glandular-viscid; bracts pilose or villous. | → 9 |
9. Racemes usually 1–5-flowered; corollas pink, purple, or bluish, not yellow, ochroleucous, or white (except in white morphs). | → 10 |
10. Corollas (14–)16–22 mm; leaflets 9+, alternate, opposite, subopposite, widely scattered, or fasciculate; stipular margins with clavate processes mixed with cilia. | O. arctica |
10. Corollas 6–20(–24) mm; leaflets 5–17, widely scattered or opposite, not fasciculate; stipular margins ciliate, without clavate processes (except in some O. nigrescens). | → 11 |
11. Legumes erect, usually black-pilose, rarely glabrous or white-pilose; stipules usually prominent, glabrous or sparsely pilose abaxially, stramineous; interior Alaska, Yukon, Northwest Territories, British Columbia. | O. scammaniana |
11. Legumes spreading to ascending, glabrous or pilosulous; stipules not especially conspicuous, pilose, silky-pilose, villous, or glabrous abaxially, whitish to light tan, grayish, or black; widespread. | → 12 |
12. Calyces usually conspicuously swollen or inflated at anthesis, investing legumes or nearly so (if not conspicuously inflated, O. lagopus var. atropurpurea, calyx villous to shaggy-villous); Alberta, Colorado, Idaho, Montana, Nebraska, South Dakota, Utah, Wyoming. | → 13 |
13. Legumes strigose-canescent, leathery, rigid at maturity; Wyoming. | O. nana |
13. Legumes villous, papery, not rigid at maturity; Alberta, Colorado, Idaho, Montana, Nebraska, South Dakota, Utah, Wyoming. | → 14 |
14. Bracts ovate to broadly lanceolate, flat; plants pulvinate-cespitose; Colorado, Nebraska, Utah, Wyoming. | O. multiceps |
14. Bracts ovate-lanceolate to lanceolate, margins involute; plants cespitose but not pulvinate; Alberta, Idaho, Montana, South Dakota, Wyoming. | O. lagopus |
12. Calyces slightly inflated at anthesis, not investing legume at maturity; n Canada to sw United States. | → 15 |
15. Legumes 10–18(–23) mm, sessile or subsessile, glabrous or minutely strigose or strigulose, unilocular; racemes 1 or 2 (or 3)-flowered; Alaska, British Columbia, Yukon. | O. huddelsonii |
15. Legumes (7–)9–38(–40) mm, sessile, subsessile, or stipitate, usually pilose, pilosulous, villous, villous-pilose, hirtellous, strigulose, or strigose-pilosulous, rarely glabrous, unilocular, subunilocular, sub-bilocular, or bilocular; racemes 1–12-flowered; widespread. | → 16 |
16. Legumes ovoid-ellipsoid or bladdery-inflated, stipitate; leaflet blades falcate. | O. podocarpa |
16. Legumes oblong, oblong-ellipsoid, lanceoloid-ovoid, ovoid, or bladdery-inflated, usually sessile, subsessile, or short-stipitate (stipitate in O. nigrescens var. lonchopoda); leaflet blades not falcate. | → 17 |
17. Corollas 12–20 mm; leaflet surfaces usually silky- or silvery-canescent, villous, strigose, or loosely pilose, rarely glabrous; n North America. | O. nigrescens |
17. Corollas usually 6–12.5 mm (to 17 mm in O. oreophila var. jonesii); leaflet surfaces pilose, villous-pilose, or silky-pilose; w United States. | → 18 |
18. Racemes 3–5-flowered; legumes ellipsoid, cylindroid, bladdery-inflated. | O. oreophila |
18. Racemes 1–3 (or 4)-flowered; legumes oblong to lanceoloid-ovoid or ovoid, not bladdery-inflated. | O. parryi |
9. Racemes usually 6–many-flowered; corollas pink, pink-purple, lavender, bluish purple, blue, purple, pinkish violet, if racemes fewer-flowered, then corollas yellow, ochroleucous, or white. | → 19 |
19. Hairs malpighian; corollas usually pink-purple, rarely white. | O. lambertii |
19. Hairs basifixed; corollas pink, pink-purple, lavender, bluish purple, blue, purple, pinkish violet, white, whitish, yellowish, or creamy white. | → 20 |
20. Corollas usually 6–12.5 mm (to 17 mm in var. jonesii); legumes bladdery-inflated; Arizona, California, Nevada, Utah. | O. oreophila |
20. Corollas (10–)12–27(–28) mm; legumes cylindric, subcylindric, ovoid, ovoid-oblong, or ovoid-acuminate, not bladdery-inflated; Canada, w United States, not including Arizona or California. | → 21 |
21. Calyces swollen at anthesis, accrescent and enclosing fruit. | → 22 |
22. Calyces villous to shaggy-villous, hairs mixed blackish and white, appearing gray; legumes villous, papery to nearly membranous; Alberta, Idaho, Montana, South Dakota, Wyoming. | O. lagopus |
22. Calyces densely shaggy-hirsute and subtomentose, hairs white; legumes strigose-canescent, firm; Wyoming. | O. nana |
21. Calyces not or slightly swollen in fruit, usually ruptured by fruit. | → 23 |
23. Corollas white or yellowish. | → 24 |
24. Corollas (10–)12–20(–23) mm; leaflets 7–45; legumes papery to leathery or membranous. | O. campestris |
24. Corollas (14–)16–27(–28) mm; leaflets 7–19(–21); legumes fleshy when fresh, becoming leathery or almost woody and rigid, or thinly papery. | → 25 |
25. Leaflets 7–19(–21), blade surfaces sericeous, often densely so; racemes subcapitate to elongate, 5–20+-flowered; legumes fleshy when fresh, becoming leathery or almost woody and rigid. | O. sericea |
25. Leaflets 11–17, blade surfaces pilose; racemes relatively short to subcapitate, 2–10-flowered; legumes thinly papery. | O. arctica |
23. Corollas pinkish or purplish (rarely creamy white in O. splendens). | → 26 |
26. Calyces with blackish hairs and long, white hairs, appearing gray; leaves 1–10 cm; Alberta, Idaho, Montana, South Dakota, Wyoming. | O. lagopus |
26. Calyces with white hairs, if with both blackish and white, then not from Wyoming or adjacent states; leaves 1.5–28 cm; Alaska east to Newfoundland and Labrador, south to New Mexico. | → 27 |
27. Corollas 17–25 mm; stipules papery or membranous, light tan or pale gray; Colorado, Idaho, Montana, Nevada, Saskatchewan, Utah, Wyoming. | O. besseyi |
27. Corollas 11–22(–23) mm; stipules rigid, fragile, or membranous, purplish, yellowish, or grayish; widespread. | → 28 |
28. Corollas (14–)16–22 mm; stipular margins ciliate, with clavate processes; n, w Alaska, Manitoba, Northwest Territories, Nunavut, Yukon. | → 29 |
29. Stipules firm, usually purplish, usually well separated on elongate caudex branches; leaflets not fasciculate; Kobuk River drainage, Alaska. | O. kobukensis |
29. Stipules fragile, grayish or yellowish, strongly imbricate; leaflets usually fasciculate; Alaska, Manitoba, Northwest Territories, Nunavut, Yukon. | O. arctica |
28. Corollas 11–20(–23) mm; stipular margins ciliate or not, with or without clavate processes; n, nw North America, seldom in arctic. | → 30 |
30. Leaflets fasciculate or not; corollas 11–20(–23) mm, calyces tubes (3.7–)4–9 mm; stipules glabrous, strigose, or pilose abaxially becoming glabrate, with or without marginal clavate processes; Alaska, se, n Yukon, Alberta, n, c British Columbia, North Dakota. | O. campestris |
30. Leaflets usually fasciculate, rarely verticillate; corollas 12–16 mm, calyces tubes 5–6.5 mm; stipules silky-pilose abaxially, without marginal clavate processes; e Alaska, s Yukon, e to Hudson Bay, s to Colorado. | O. splendens |
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