Astragalus adsurgens var. robustior

  • Title

    Astragalus adsurgens var. robustior

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Astragalus adsurgens var. robustior Hook.

  • Description

    190b.  Astragalus adsurgens var. robustior

    Habit of the species; leaves 4—17 cm. long, with (9) 11—25 leaflets (4) 8-27 (33) mm. long; peduncles (3) 4—14 (16.5) cm. long; racemes (7) 16-50-flowered, the axis (0.6) 1.5—9 (13) cm. long in fruit; calyx 5.8—10.5 mm. long, strigulose with mixed black and white, all white, or rarely all black, straight or crisped hairs, the tube (4) 4.4-7 mm. long, (2) 2.3-3.2 mm. in diameter, the teeth subulate or subulate-setaceous, 1.4—4.2 mm. long, often crowded toward the dorsal side, the ventral sinus wide and deeply cut back, the orifice thus oblique; petals magenta-purple, reddish-lilac, dull blue, pale milky-white (the keel then maculate), or whitish drying creamy; banner 13-19.5 mm. long, 4-7 (8) mm. wide; wings 10.6-17.5 mm. long, the claws 5-8.3 mm., the blades 5.8-10 mm. long, 1.5-2.5 mm. wide; keel (8.8) 9.5-15 mm. long, the claws 4.9-8.3 mm., the blades 4.2-7 mm. long, 1.7-2.5 mm. wide; pod sessile or nearly so, the narrowly ovoid-, oblong-, or lance-ellipsoid body 7-12 mm. long, 2.3-3.8 mm. in diameter, densely pubescent with shorter sinuous and often some longer, straighter, mixed white and black or all white hairs; ovules 9-14 (16).—Collections: 340 (viii); representative: Calder & Kukkonen 26,781, 27,569 (NY); Raup 2778 (NY); Cody 2663 (CAS); J. M. Macoun 59,575 (NY); Macoun & Herriott 70,478 (ND, NY); C. L. Hitchcock 16,612, 17,922 17,961 (NY, RSA, WS); Cronquist 6749 (NY, RSA, SMU, WS); Brenkle 4317 (CAS, SMU, TEX); Sheldon (from Lake Christina, Minnesota) in 1892 (NY, WIS); A. Nelson 646 (NY, RM, WS); Ripley & Barneby 7981 (CAS, RSA); Clokey 2809 (NY, WIS, TEX); Hitchcock & al. 4136 (CAS, WS, WTU); A. & R. Nelson 2199 (NY, RM, SMU).

    Plains, prairies, and dry hillsides, usually in bare rocky or gravelly places, northward on gravelly or shingly lake shores or river banks, in various soils but most abundant on sedimentary bedrock, widespread and locally abundant between 700 and 6400 feet along the east foothills of the Rocky Mountains and on the adjoining plains and prairies, from northeastern New Mexico to Alberta, and through the Peace River district into the northernmost Rocky Mountains in northeastern British Columbia, to Great Slave Lake in southwestern Mackenzie, and east (becoming less frequent) to northeastern and southwestern Manitoba, western Ontario, western (and one station in southeastern) Minnesota, and northern Iowa, in Colorado ascending westward into the higher valleys and parks up to 11,000 feet, where found on brushy hillsides, in mountain meadows, and in open pine forest; extending west of the Continental Divide to the Columbia Basin in southern British Columbia and northeastern Washington, to central Idaho, and to extreme northeastern and possibly central Utah; introduced in Yukon; reported from Kansas (Fernald, 1950, p. 911).—Map No. 77—May to August, fruiting into September northward and at great altitudes.Astragalus adsurgens var. (ß) robustior (stouter) Hook., Fl. Bor.-Amer. 1: 149. 1831. —"Common in the mountain-vallies, from the Kettle Falls to the sources of the Columbia, on the west side of the Rocky Mountains. Douglas."—Holotypus, labeled "Mountain vallies and subalpine hills on the banks of Flathead River, Douglas." K! presumed isotypus, labeled by Torrey "A. adsurgens P Hook.," NY!—A. nitidus (shining) Dougl. ex Hook., l.c. in syn., nom. nud., validated by Jones in Proc. Calif. Acad. Sci. II, 5: 646. 1895.—A Douglas spm. at BM is so named, but labeled "On the Blue Mountains and near Kettle Falls, 1826."—A. nitidus var. robustior (Hook.) Jones, Contrib. West. Bot. 10: 64. 1909. A. adsurgens ssp. robustior (Hook.) Welsh in Ia. State Jour. Sci. 37: 357. 1963.

    Astragalus striatus (striate) Nutt. ex T. & G., Fl N. Amer. 1: 330. 1838.—"Plains and hills of the Platte and Missouri.. . Nuttall"—The sp. was based partly on A. Laxmanni sensu Nutt., Gen. 2: 99, non Jacqu., partly on A. adsurgens var. robustior Hook., and partly on Nuttall material from the Platte; it might best be considered a nomenclatural synonym of the preceding. A spm. labeled "A. adsurgens. Louisiana. Nuttall, from Lambert’s Herb.," PH (herb. Pursh.)! is authentic for the first element; another, labeled "Astragalus *striatus. A. Laxmanni Nutt. Gen. R. Mts. Platte," is authentic for the third.

    Astragalus Hypoglottis var. robustus (stout) Hook, in Lond. Jour. Bot. 6: 210. 1847.— "High gravelly plains of the Upper Platte near Laramie’s Fork... ([Geyer] No. 126)."—Holotypus, K! isotypi, BM, G!

    Astragalus sulphurescens (turning sulfur-yellow, of the dried petals) Rydb. in Bull. Torr. Club 28 : 36. 1901.—"Colorado: Georgetown, 1895, P. A. Rydberg."—Holotypus, collected August 18, 1895, NY!

    Astragalus Crandallii (Charles Spencer Crandall, 1852-1929, professor of botany at Colorado State Agricultural College, 1889-1899) Gand. in Bull. Soc. Bot. France 48: xiv. 1902.— "Hab. Colorado, ad Larimer (C. S. Crandall), alt. 7-8000 ped."—Holotypus (presumably at LY), not examined.

    Astragalus adsurgens var. pauperculus (somewhat depauperate) Blank, in Mont. Agr. Coll. Sci. Stud. 1: 72. 1905.—"Billings, July 7, 1902 ... "—Holotypus (presumably at MONT), not examined; apparently collected by Blankinship, and described as the opposite extreme in vigor to var. robustior.

    Astragalus adsurgens var. albiflorus (white-flowered) Blank, in op. cit., p. 71. 1905.—"Field on 7-mile road, Helena, July 19, 1898, E. N. Brandegee."—Holotypus (presumably MONT), not examined; described as the white-flowered state.

    Astragalus Chandonnetti (Rev. Z. L. Chandonnet, "who works ardently and enthusiastically in the botanical field whenever season and sacerdotal duties permit") Lunell in Amer. Midl. Nat. 2: 127. 1911.—"... in dry soil at McHugh near Detroit, Minn., on June 16, 1911, by Rev. Father Z. L. Chandonnet."—Holotypus (Chandonnet 3135), MINN!—A. striatus fma. Chandonnetti (Lunell) J. W. Moore in Rhodora 59: 8. 1957.

    Astragalus sulphurescens var. pinicola (living among pines) Kelso in Rhodora 39: 150. 1936.—"Colorado: Dry hillsides in the rock pine association, Bryson’s Camp [Rocky Mountain National Park], alt. 8250 ft., August 8, 1836, L. and E. H. Kelso 319, 320 (Type in my collection)." —Holotypus (herb. Kelso.), not examined; isotypus (Kelso 320), GH!

    A formidable synonymy has grown up around the common American form of the standing milk-vetch, var. robustior, and it remains as an index of the polymorphism encountered everywhere in A. adsurgens, whether in the Old or New Worlds. Apart from variation in stature and amplitude of the foliage, which can safely be attributed to accidents of environment or season, the variable features of var. robustior are size of the flowers, length of the calyx- teeth, color of the petals and of the hairs in the inflorescence (including the pod), and density or dispersal of the pubescence considered either separately or together. In his summary monograph Rydberg maintained three American species in the complex, stressing differential characters which for purposes of comparison and discussion may be tabulated as follows (abstracted from keys and descriptions in Rydberg, 1929, pp. 441, 449, 450).

    A. striatus

    A. Chandonnetii

    A. sulphurescens

    Calyx

    tube

    4—6 mm.

    4 mm.

    4-5 mm.

    teeth

    3—4 mm.

    3—4 mm.

    as long as tube

    Petals

    purple rarely

    white or

    ochroleucous

    white

    ochroleucous

    Leaflets

    13-25, strigose

    13-19,

    11-19, glabrate

    or glabrate above

    silvery-silky

    Pod

    strigose

    white-hairy

    black-hairy

    It will be seen than no significant difference was claimed for A. Chandonnetti other than the more silvery foliage. It represents, in fact, a series of pale- or white-flowered forms such as occur commonly in populations of bluish- or purple-flowered plants as well as in colonies of uniformly pallid hue. Color of the petals is not correlated with density of pubescence, and pale coloring of the flowers is not correlated with a white-hairy inflorescence or pod. The case of A. sulphurescens is different, for this apparently coincides with an incipient racial differentia

    tion correlated with a range at comparatively high elevations in the Colorado Rocky Mountains. In the Front Range especially, but also farther southward, the leaflets of var. robustior are almost consistently glabrous above, a state unusual (though not unknown) elsewhere in the variety’s range. However the glabrescent and consequently green rather than ashen herbage of the Colorado populations does not go hand in hand with pallid petals. It must be emphasized further that the petals, even in the Front Range, are not truly ochroleucous, but white when fresh, fading yellowish (as the epithet sulphurescens literally means) in drying. In Colorado one finds concurrently with glabrescent foliage a tendency toward relatively long calyx-teeth, but similarly long teeth are found in silvery-pubescent plants sporadically northward. The presence of black (or fuscous) hairs on the pod, mixed with white in various proportions, is a common feature of the species, but it has no racial significance and no recognizable pattern of occurrence. The Colorado material that I have seen is quite heterogeneous in the technical characters singled out for emphasis by Rydberg, and is notable finally for commonly glabrate foliage, commonly long calyx-teeth (2.6-4.2 mm.), and commonly whitish petals, but all these characteristics are seldom associated in the same plant. The var. pinicola, of which the petals were described as "mostly white slightly yellow after drying," supposedly differed from A. sulphurescens in a slightly deeper calyx-tube and erect rather than "reflexed" (meaning, I suppose, distally recurved) teeth, but is only one of several minor variants in the Colorado mountains.

    The remaining synonyms of var. robustior have little but a historic interest. The typus of A. Crandallii has not been examined, and no duplicate has been identified as such in an American herbarium. I follow Rydberg in interpreting it as a white-flowered form of var. robustior similar to that described as A. sulphurescens. Blankinship’s var. pauperculus corresponds with a slender or depauperate phase found occasionally in the Rocky Mountain foothills and very commonly on outcrops in the higher prairies. Relatively small flowers and short racemes are commonly but not consistently correlated with dwarf stature and narrow leaflets.