Astragalus calycosus Torr. ex S.Watson var. calycosus

Tufted or mounded, low and dwarf, the leaves 1—7 cm. long, the scapes either shorter than the leaves or, if longer, weakly ascending and reclinate in fruit; leaves often palmately trifoliolate, but as commonly with 1—2 lateral pairs, the rachis then not over 1 cm. long; racemes (1) 2—6 (8)-flowered, the axis 2—20 (25) mm. long in fruit; calyx 5.2—10.6 mm. long, the tube 4-6.4 (6.7) mm., the teeth (1) 1.5-4.2 mm. long; petals whitish to bright pink-purple, the banner10-16.5 (20.8) long; wings 10.2-17 (19.7) mm. long, the terminal lobes 1.1-4.5 mm. long, the intervening sinus naked or appendaged; keel 7.4-11.6 (12.7) mm. long.—Collections: 104 (xvi); representative: Hitchcock & Muhlick 8996 (CAS, NY, WS, WTU); J. & C. Christ 17,740 (ID, NY, RSA); Maguire & Holmgren 25,245, 25,927 (NY, RSA); M. & G. Ownbey 2869 (CAS, NY, RSA, SMU, WS); Clokey 8002 (CAS, NA, NY, OB, RSA, SMU, TEX, WIS, WS, WTU); Ripley & Barneby 4377 (RSA), 10,634 (CAS, RSA); Duran 3285 (CAS, NY, OB, WIS, WS); Wiggins & Rollins 563 (CAS); Eastwood & Howell 968 (CAS).

Dry open hillsides, knolls and ridges, in sandy or gravelly clay soils commonly derived from limestone, but also on granite, shale, sandstone, and probably other formations, in Idaho sometimes in volcanic sand, with piñon, juniper, and sagebrush, mostly 4200-8500, rarely (in Nevada) up to 11,300 feet, widespread and locally plentiful from Death Valley northwest along the east slope of Owens Valley to Mono Lake, California, northeast across Nevada to the Bear River in southwestern Wyoming and the head of the Lost Rivers in southcentral Idaho; southeastern Oregon (acc. Peck, 1941, p. 450); east in Utah (becoming rarer) to the Sevier Valley, and south (often intergrading with var. scaposus) to both rims of the Grand Canyon in northwestern Arizona.—Map No. 154.—May to early July.

Astragalus calycosus (with conspicuous calyx, not especially apt) Torr. ex Wats., Bot. King 66, Pl. X, figs. 4—7. 1871.—"Found in the West Humboldt, East Humboldt, and Clover Mountains, Nevada ... also by Dr. Torrey, in flower only, in Western Nevada ... (257)." Lectotypus, Watson 257, from the East Humboldt Mountains, July, 1868, US! isotypi, GH (in part, mixed with var. mancus), NY!—Tragacantha calycosa (Torr. ex Wats.) O. Kze., Rev. Gen. 943. 1891. Hamosa calycosa (Torr. ex. Wats.) Rydb. in Bull. Torr. Club 54: 17. 1927.

Astragalus brevicaulis (short-stemmed) A. Nels. in Bot. Gaz. 26: 9. 1899.—"...southern Wyoming ... Type specimen no. 4601, from near Fort Bridger, June 9, 1898."—Holotypus, RM! isotypi, NY, US!

The Torrey milk-vetch, var. calycosus, is most commonly encountered in the form of little tufted plants scattered among the sagebrush, each composed of some three to a dozen crowns which are clustered on a taproot rarely attaining the thickness of a pencil. Although decidedly perennial, plants of this type probably endure for only a few years; a prolific crop of flowers and seeds ensures propagation of their kind in favorable seasons. In central Nevada, particularly on calcareous knolls in the higher valleys, var. calycosus is represented by a pulvinate phase in which the older plants may consist of several hundred greatly congested leafy crowns. These are elevated on an elaborately forking, clay-impacted caudex and anchored to the ground by a thick trunklike caudex, which must require a decade or more to reach its full development. The mounded form of the Torrey milk-vetch is often associated with other polsterpflanzen (notably Lepidium nanum Wats., Leptodactylon caespitosum Nutt., Phlox species, and a parallel development of Oxytropis oreophila Gray—cf. Barneby, 1952, p. 214) and is interpreted as an ecotype or minor variant, since no difference can be found in the reproductive parts. From central Nevada northward and eastward the flowers of var. calycosus are most commonly whitish, although often faintly tinged or veined in early anthesis with flesh-pink or rosy-lavender; occasional forms with the banner margined or suffused with lively purple or magenta occur as far north as the Snake River and southwestern Wyoming, as in the typus of A. brevicaulis. Southward the flowers are almost consistently bicolored, with white or whitish wing-tips contrasting with a highly colored banner and keel-tip. No correlation has been found between pigmentation of the flowers and type of soil, although possibly the most brightly tinted forms occur only on sedimentary formations.

On the upper Humboldt River in Nevada, and thence northward and eastward, the wing- petals of var. calycosus nearly always bear a minute appendage in the sinus between the apical lobes. The appendage takes two forms, appearing either as a threadlike structure arising in the notch and directed forward between the lobes, or as a flat, subulate auricle produced from the base of the interior lobe and directed backward or more commonly across the opposite lobe on the petal’s inner face. Transitions between the two sorts are often observed, and the whole appendage varies from a rudiment up to 1.1 mm. long. Within the same northern area the flowers tend to be a little larger than they are southward, with banner 11-16.5 mm. and keel 8-11.6 mm. long; in eastern California and across central Nevada to Utah and Arizona, the banner is commonly only 10-13 mm. and keel 7.4—9.4 mm. long. While of some interest as evidence of incipient racial differentiation, the characters noted are too slight and too feebly expressed to be of taxonomic value, especially when occasional examples of small- flowered individuals or colonies are known from both sides of the Snake River Plains. A remarkably showy variant of var. calycosus, with banner up to 20.8 mm. long (and other petals, as noted parenthetically in the foregoing description, in proportion), has been collected near Pocatello, Idaho (Christ & Ward 7122, ID, NY); although the wings lack appendages, the plants appear not to differ significantly from sympatric forms of typical A. calycosus.

In southeastern Nevada and adjoining Utah and Arizona, var. calycosus passes by degrees into var. scaposus. While some colonies are precisely typical, occasional individuals or small colonies are characterized by unusually short calyx-lobes, or exserted (but commonly decumbent) scapes, or by leaflets and flowers abnormally numerous. Some of these can be assigned to a varietal category only by arbitrary judgment.

No specimen of A. calycosus actually collected by Torrey in Nevada has been seen either at GH or in the Torrey herbarium (NY), despite Watson’s report. The plant to which Torrey originally applied the epithet calycosus is probably that collected by Stretch at a place called the "Kaolin Hills" (NY), a name not found on modern maps.