Astragalus Palmeri

Vigorous, low and diffuse, with a potentially perennial taproot, even though of rapid growth and usually short duration, sometimes flowering the first season, densely to quite thinly strigulose with fine, appressed and commonly a few narrowly ascending, straight or partly sinuous hairs up to 0.35-0.6 mm. long, the herbage varying from silvery-canescent to greenish-cinereous or rarely green, the leaflets commonly pubescent on both sides, often more densely so above than beneath, rarely glabrous or medially glabrescent above; stems several or numerous, prostrate or weakly ascending distally, (1) 1.5-5 dm. long (or in some seedling but already fertile plants only 1-3, erect or ascending, and 0.5-1 dm. long), simple or either branched or spurred at 1-3, more rarely at all nodes preceding the first peduncle, cinereously strigulose or glabrate, mature plants forming leafy mats or low, depressed and flattened clumps; stipules submembranous, the small lower ones becoming papery and fragile, (1.5) 2-6.5 mm. long, triangular or deltoid-acuminate, about semiamplexicaul-decurrent, either glabrous or pubescent dorsally, the margins ciliate and often beset with a few minute processes; leaves (2) 3-13 (16) cm. long, all petioled or the uppermost subsessile, with (9) 11-21 oblong, oblong-ovate or -obovate, or broadly to narrowly elliptic, acute, obtuse and mucronulate, rarely retuse-emarginate, flat or loosely folded leaflets (3) 5-25 mm. long, the midrib prominent beneath; peduncles ascending or incurved, 4—13 cm. long, nearly always shorter than the leaf; racemes loosely (or at early anthesis subcompactly) (10) 20—40-flowered, the flowers widely ascending or spreading at full anthesis, the axis early elongating, (3.5) 4—21 cm. long in fruit; bracts submembranous, ovate-triangular or lanceolate, 0.8—2.6 mm. long; pedicels ascending and a little (at times strongly) arched outward in age, at anthesis 0.5—1.8 mm., in fruit a trifle thickened, 0.8—3 (3.4) mm. long, persistent; bracteoles nearly always 2, commonly minute, sometimes 0; calyx 3.6—6.6 mm. long, strigulose with all black, all white, or mixed black and white hairs, the slightly oblique disc (0.6) 0.7-1.1 mm. deep, the campanulate or ovoid-campanulate, pallid or purplish tube (2.2) 2.7—3.8 mm. long, (1.8) 2—3.4 mm. in diameter, the subulate or triangular-subulate teeth (0.9) 1—2.8 mm. long, the ventral pair either longer or shorter but commonly broader than the rest, the whole becoming papery, ruptured, marcescent; petals mostly bright pink-purple with striate eye in the banner, more rarely ochroleucous tipped or veined with dull, lurid purple; banner abruptly recurved through nearly 90°, ovate- or obovate-cuneate, shallowly notched, 7-10.3 mm. long, 5.2-8 mm. wide; wings 6.7-9.2 mm. long, the claws 3.7 mm., the obliquely oblong-elliptic, -oblanceolate, or -obovate, obtuse, gently incurved blades 4.4—6.2 mm. long, 1.7—3 mm. wide; keel 6.2—8.8 mm. long, the claws 2.5-3.7 mm., the lunately half-elliptic blades 4.1-5.5 mm. long, (2) 2.2-2.6 mm. wide, abruptly incurved through 90-95° to the triangular, obtuse or subacute, often slightly porrect and sometimes beaklike apex; anthers (0.4) 0.45-0.7 mm. long; pod ascending, spreading, or (when large) declined, sessile on the flat or conical receptacle, obliquely ovoid-ellipsoid or ovoid-acuminate, moderately to strongly inflated, 0.9-2.3 cm. long, (4) 5-15 (17) mm. in diameter, rounded or broadly to narrowly cuneate at base, contracted distally into a compressed, triangular or deltoid-acuminate, erect or slightly incurved beak 1/3-1/5 as long as the body (and 2-7 mm. long), the body either a little dorsiventrally or laterally compressed, the filiform sutures either depressed or prominent, the ventral one varying from nearly straight to a trifle less convex than the dorsal one, the lateral faces distended and plumply rounded, the thin, pale green or purple-speckled or -suffused, thinly to densely strigulose valves becoming stramineous, papery (but hardly diaphanous), not inflexed, the funicular flange narrow or obsolete (0-0.6 mm. wide); dehiscence both apical and basal, after falling; ovules (7) 12-31; seeds orange- or mahogany-brown, ± rugulose or punctate, dull, 2-3 mm. long.—Collections: 51 (iii); representative: S. B. & W. F. Parish 735 (DS, ND, NY); Moran 837 (CAS); L. S. Rose 35,700 (CAS, WS); Munz 15,128 (CAS, POM); Epling & Robison (from Box Canyon) in 1932 (CAS, NY); Ripley & Barneby 10,083 (CAS, RSA); Pringle (from Baja California) in 1882 (ND, NY); Gander 2630 (SD).

Open gravelly or sandy flats, hillsides, canyon benches and boulder-strewn slopes or washes, commonly with piñon, Joshua-tree, scrub-oaks or manzanitas, but sometimes brought down and vigorously flourishing on the desert floor, mostly on granitic bedrock, (500) 1000-4000 (5450) feet, rather common and locally abundant around the west and northwest edge of the Colorado Desert, from the head of Coachella Valley (foothills of the San Bernardino, Little San Bernardino and Eagle Mountains) south into northern Baja California in lat. 30° N.—Map No. 116.—December to June.

Astragalus Palmeri (Edward Palmer, 1831-1911, widely traveled plant collector and ethnologist) Gray in Proc. Amer. Acad. 7: 398. 1868.—"Camp Grant, in southern Arizona, Dr. Edward Palmer, comm. Engelmann."—Holotypus, dated April 22, 1867, GH! isotypus, MO!— Tragacantha Palmeri (Gray) O. Kze., Rev. Gen. 947. 1891. Phaca Palmeri (Gray) Rydb. in N. Amer. Fl. 24: 355. 1929.

Astragalus Vaseyi (George Richard, son of agrostologist George Vasey) Wats. in Proc. Amer. Acad. 17: 370. 1882.—"At Mountain Springs, San Diego County, California, by G. R. Vasey, 1880...’’—Holotypus, Vasey 139, collected in June, 1880, GH! isotypi, NY, P, US!— Phaca Vaseyi (Wats.) Rydb. in N. Amer. Fl. 24: 354. 1929.

Astragalus metanus (of the border) Jones in Proc. Calif. Acad. Sci. II, 5: 666. 1895.— "Hanson’s Ranch, Lower California, near the border, Brandegee, April 18, 1885 ... The type is in the California Academy of Sciences."—No corresponding spm. found at CAS, and T. S. Brandegee is not known to have been in Baja California in 1885. Typus probably collected by C. R. Orcutt, who collected spms. at Hansen’s Ranch on April 18, 1885; presumed isotypi, ND (No. 138), NY, US (No. 510), WS!—Phaca metana (Jones) Rydb. in N. Amer. Fl. 24: 354. 1929. Astragalus Vaseyi var. metanus (Jones) Munz & McB. in Bull. S. Calif. Acad. 31: 66. 1932.

Astragalus Vaseyi var. Johnstonii (Ivan Murray Johnston, 1898-1960, world authority on Boraginaceae, student of American desert floras) Munz & McB. ex Munz in Bull. S. Calif. Acad. 31: 66. 1932.—Type from Keyes Ranch, Little San Bernardino Mts., Munz & Johnston 5271 ...’’—Holotypus, collected May 7, 1922, POM! isotypi, DS, NY (fragm.)! A. Palmeri var. Johnstonii (Munz 8c McB.) Barneby ap. Shreve & Wiggins, Veg. Fl. Son. Des. 702. 1964.

The Palmer milk-vetch is closely related to A. Douglasii, from which it differs in its smaller (ordinarily very much smaller) fruit, fewer ovules, and (with rare exception mentioned below) in its purple petals. The species is polymorphic, varying from one population to the next in size of the pod, length of the calyx-teeth, color of the calyx-hairs and of the petals, and in density and distribution of the pubescence. The variations are to a large degree correlated with a north-south trend in dispersal, for the smallest pods, most silvery herbage, and shortest calyx-teeth are constantly associated only southward; the opposite conditions, complicated by the occurrence of ochroleucous flowers, are encountered all together only about the north end of Coachella Valley. However, the variation is continuous and even though a given extreme may be confined to a small area and dominant within it, no single combination of characters excludes all others from its range. Thus in Morongo Valley and the Little San Bernardino Mountains, where A. Palmeri is represented most commonly by a robust, glabrescent phase with large pods described as A. Vaseyi var. Johnstonii, the leaflets vary, sometimes even within a small colony of plants otherwise alike, from glabrous to densely strigulose on the upper side; in the same area the 21-31-ovulate pod varies from 1.6 to 2.3 cm. in length, the calyx-teeth from 1.4 to 2.8 mm., and the petals from ochroleucous faintly veined with brownish-purple to bright magenta-purple. Between Palm Springs and Vallecito, in the foothills and up to 4000 feet in the Santa Rosa Mountains, the leaflets of the Palmer milk-vetch vary from thinly to canescently strigulose above, the 14-22-ovulate pod is 1.1-1.9 cm. long, the calyx-teeth mostly 1.4—2 mm. long, and the petals are consistently purple. Following the species southward from the Borrego Desert into northern Baja California, we find the pod on the average smaller, mostly 0.9-1.4 (rarely to 1.8) cm. long, and 12-17-ovulate; while the calyx- teeth are 0.9-1.7 mm. long, the herbage nearly always gray or silvery, and the petals once again always purple. The vesture of the calyx varies from black to white through the range of the whole species, and as usual the preponderance of hairs of one color has no taxonomic significance. The black-calyxed var. metanus is only one of many minor variants; in fact, Orcutt himself collected white-hairy plants in the type-station.

The identity of A. Palmeri with what has been known to California botanists as A. Vaseyi was first noted by Tidestrom (Fl. Ariz. & New Mex. 210. 1941). The distance between the supposed type-station in southeastern Arizona and the main range of the species in California is remarkable but not without precedent, for bicentric dispersals of a similar type are well known (cf. Kearney & Peebles, 1942, p. 8). Palmer was at Camp Grant (cf. McVaugh’s Life) at the day specified on the duplicate labels at MO and GH, and there seems no good reason to doubt the authenticity of the data. It is odd, nevertheless, that no further collections of A. Palmeri have since been made in Arizona, despite deliberate search around Camp Grant. A specimen cited by Kearney & Peebles (Mohr from the San Carlos River, US) is a mixture of genuine A. Palmeri (possibly a fragment of the typus) and A. arizonicus, a species common in southeastern Arizona. Palmer was in San Diego County, California, in the summer of 1861 while working for the State Geological Survey, and there is a bare possibility that the astragalus was actually collected in California during that season. Pending confirmation of its existence in Arizona, the type-station has been omitted from Map 115.