Astragalus eremiticus

Title

Astragalus eremiticus

Authors

Rupert C. Barneby

Scientific Name

Astragalus eremiticus E.Sheld.

Description

163. Astragalus eremiticus

Of moderate stature, slender or quite stout, with a woody taproot and knotty root-crown or shortly forking caudex, densely to quite thinly strigulose with straight, appressed hairs up to 0.3-0.7 mm. long, the herbage green or cinereous, the leaflets commonly bicolored, of lighter and brighter green and commonly glabrous above; stems several, erect and ascending in clumps, more rarely ascending and diffuse, 1-5 dm. long, composed of ± 4-8 developed intemodes, simple or spurred at 1-3 of the lower axils; stipules 3-11 mm. long, the lowest papery- scarious, often loosely imbricated, mostly ovate, amplexicaul-decurrent around half or more of the stem’s circumference, the median and upper ones narrower, subherbaceous, with triangular or lanceolate, erect or recurved blades; leaves (3) 4.5-18 cm. long, the lower ones slender-petioled, the upper shortly so or subsessile, with 11-23 ovate, oblong, elliptic, or linear, obtuse or retuse, flat or folded leaflets 5-26 mm. long; peduncles erect, (1.5) 2.5-17 (24) cm. long, a little shorter or longer than the leaf; racemes (7) 10-26-flowered, either loose or compact at anthesis, the flowers ascending, spreading, or declined, the axis more or less elongating, (1.5) 2.5-18 cm. long in fruit; bracts membranous, ovate or lanceolate, 1.5—4 mm. long; pedicels at anthesis slender, 0.7-1.5 mm. long, in fruit thickened, 1.5-3.5 mm. long, spreading-ascending at an angle of ± 45°; bracteoles 0-2, commonly present; calyx 5.4—9.5 mm. long, strigulose with black or mixed black and white hairs, the subsymmetric or oblique disc 0.9-1.6 mm. deep, the deeply campanulate tube 4.4-8 mm. long, 2.2-4 mm. in diameter, the subulate teeth 1-2.6 mm. long, the whole becoming papery, marcescent unruptured; petals ochroleucous immaculate, ochroleucous with maculate keel-tip, or pale and dull purple to bright pink-purple with contrasting white or pallid wing-tips; banner recurved through ± 45°, rhombic-obovate or -oblanceolate, 12-20 mm. long, 5.6-10 mm. wide; wings 10.2-18 mm. long, the claws 5.3-8.2 mm., the narrowly oblong-oblanceolate, obtuse or emarginate, straight or slightly incurved blades 6-9 mm. long, 1.8-3.1 mm. wide; keel 9.4 14.4 mm. long, the claws 5.4-8 mm., the half-elliptic blades 5-7.3 mm. long, gently incurved through ± 80 (90)° to the bluntly deltoid apex; anthers 0.550.75 (0.8) mm. long; pod stipitate, erect or exceptionally deflexed, the stipe usually incurved-ascending to bring the body to vertical, 6-15 mm. long, the body narrowly oblong-ellipsoid, solid or sometimes a trifle tumid, 1.5-2.7 (3) cm. long, 3.5-8 (9) mm. in diameter, cuneately contracted at base and tapering into the stipe, abruptly contracted distally into a short, triangular, laterally compressed, porrectly cuspidate beak, otherwise bluntly triquetrous and a little dorsiventrally compressed, with low-convex lateral and openly grooved dorsal faces, keeled ventrally by the prominent, often purplish suture, the slightly or decidedly fleshy, green or purple-suffused or -speckled, glabrous valves becoming thinly or stiffly leathery, reticulate, brownish-stramineous, inflexed as a complete or partial septum 0.5—1.2 mm. wide; ovules 17—32; seeds (little known) olivaceous, smooth or sparsely pitted, 2.8—3.2 mm. long.—Collections: 89 (x); representative materials cited in the discussion.

Open valleys, foothills, rolling plains, barren clay hills, and sandy or clayey bluffs and knolls, commonly among sagebrush or (southward) in piñon-juniper forest, 2100—6800 feet, on diverse soils (noted in more detail below), widespread and locally plentiful from the foothills bordering the lower Snake River Plains in southwestern Idaho (southern Washington to Twin Falls County) and southeastern Oregon (extreme southern Baker and Malheur Counties) south through eastern Nevada to the Colorado River, extreme southwestern Utah (Washington and Kane Counties) and northwestern Arizona (Mohave County, on both sides of the Colorado; one station on the upper Verde River in Yavapai County). Map No. 65.—April to July, the fruit long persisting.

Astragalus eremiticus (dwelling hermitlike in desert on lonely places) Sheld. in Minn. Bot. Stud. 1: 161. 1894.—"Collected in the Beaverdam mountains, southern Utah, May, 1874, by Dr. C. C. Parry; also at Sprucemont, Nevada, July, 1891, by M. E. Jones ... ’’—Holotypus (Parry 45, from St. George), MINN! isotypi, GH, MO, NY, P!—A. arrectus var. eremiticus (Sheld.) Jones in Proc. Calif. Acad. Sci. II, 5: 665. 1895. Tium eremiticum (Sheld.) Rydb. in Bull. Torr. Club 40: 49. 1913. A. eremiticus var. typicus Barneby in Proc. Calif. Acad. Sci. IV, 25: 155. 1944.

Astragalus Cusickii Rydb. in Bull. Torr. Club 26: 541. 1899.—“Malheur, 1885, W. C. Cusick 1238 ... ”—Holotypus, GH!—A. malheurensis (of Malheur, Oregon) A. Heller, Cat. N. Amer. Pl., Ed. 2, 7. 1900, a legitimate substitute (non A. Cusickii Gray, 1878). Tium malheurense (A. Heller) Rydb. in N. Amer. Fl. 24 : 391. 1929. A. eremiticus var. malheurensis (A. Heller) Barneby in Amer. Midl. Nat. 41: 501. 1949.

Astragalus boiseanus (of Boise, Idaho) A. Nels. in Bot. Gaz. 53: 223. 1912.—“C. N. Woods, No. 4, Caldwell, Idaho, May 1910; Francis Macbride, No. 257, Boise Hills, June 18; No. 112 (type) Big Willow, May 27, 1910.”—Holotypus, Macbride 112, RM! isotypi, GH, MO, NY, US, WIS! Paratypi, Macbride 257, MO, RM!—Cystium boiseanum (A. Nels.) Rydb. in Bull. Torr. Club 40: 50. 1913.

Astragalus eremiticus var. spencianus (of Spencemont, Nevada) Jones, Contrib. West. Bot. 10: 60. 1902.—“ ... the characteristic form of eastern Nevada ... ”—Lectotypus (Barneby 1944, p. 155), Jones (from Spencemont, Nevada) in 1891, POM!

The hermit milk-vetch, A. eremiticus, is a variable and perplexingly polymorphic species, composed of numerous races which I cannot for the present define in terms exact enough to serve taxonomic purposes. The variable features, variably correlated, are: density of vesture; width of leaflets with consequent alteration of the plant’s gross aspect; length and openness of the raceme; orientation of the flower at anthesis (the calycine disc oblique when nodding, symmetric otherwise); width of calyx-tube; color and, to some degree, length of petals; width of pod; and in one rare instance orientation of the pod which is ordinarily held vertically erect on a slender, spreading and distally incurved stipe. The racial problem in A. eremiticus has engaged my attention over a number of years, and I have maintained in the past a glabrescent, broad-leaved var. eremiticus (or var. typicus, l.c.) with open racemes of ascending, purple or bicolored flowers ranging (mostly calciphile) from Lincoln County, Nevada, to northwestern Arizona and adjoining Utah; a var. spencianus differing in its more compact racemes of declined, whitish flowers dispersed from eastcentral Nevada north to the limit of the species; and a var. malheurensis, supposedly distinguished by its linear leaflets and often purple flowers (an inexact concept), thought to be endemic to southwestern Idaho and adjoining Oregon. The situation as I had projected it has been shown by recently acquired material to be more complicated than I had supposed, and it will be necessary to reassemble all available material at one place before the evidence can be re-evaluated. A review of more complete data may reveal the existence of five or more varieties, ecologically as well as morpholgically isolated. As a basis for further study, I present here a tentative key to what I am obliged to call minor variants, although at least some of them are almost certainly of a higher category.

1. Body of the pod erect on a spreading, distally incurved stipe; widespread, from Mohave County, Arizona, northward (2)

2. Calyx-tube narrowly cylindric, 2.2-2.1 mm. in diameter; flowers ascending at anthesis (the calycine disc subsymmetric), relatively small, the keel 9.4-11 mm. long; petals ochroleucous with prominent purple keel-tip; leaflets linear, the widest on a plant 1-2.5 (3) mm. broad.—Hot, sandy bluffs and gullied clay hillsides or gravelly flats, mostly 2100-2500 feet, locally common along the Snake River and its immediate affluents in Washington and Payette Counties, Idaho, and adjoining Malheur County, Oregon. (A. malheurensis A. Hell.; A. eremiticus var. malheurensis Barneby, p. p.) = M. v. 5; collections: 9 (i); representative: M. & G. Ownbey 2761 (CAS, NY, RSA, SMU, WS), Peck 25,934, 25,936 (RSA); J. & C. Christ, 17,281 (ID, NY, RSA). Intergrades with m. v. 3 & 4.

2. Calyx-tube broader, (2.7) 3-3.8 (4) mm. in diameter; flowers mostly larger, the keel over 11.5 mm. long or, if shorter, then the petals purple; petals either ochroleucous and immaculate or bicolored, purple with pale wing-tips (3)

3. Calycine disc subsymmetric, the flowers ascending in lax, distantly flowered racemes, the fruiting axis 5-17 cm. long in fruit; pod relatively thin-textured. Leaflets mostly ovate-oblong, the widest about 6-8 mm. broad, thinly pubescent beneath; petals bicolored, exceptionally ochroleucous, the keel 10.6-12.6 mm long.—Low hills and open slopes in thin sagebrush or piñon-juniper forest, mostly on limestone, 3000-5550 feet, local, Muddy River Valley in Lincoln County, Nevada, east to the Virgin River in Washington County, Utah, south to Toroweap Point and Peach Springs near the Colorado River in Mohave County, Arizona. (A. eremiticus, sens. strict.) = M. v. 1; collections: 19 (iii); representative: Ripley & Barneby 4313, 4408 (CAS, RSA); Palmer 121 in 1877 (NY); Jones 5003, 5070, 5071, 5082b (all NY, POM).— Pod variable, sometimes decidedly tumid, 4—9 mm. in diameter.