Astragalus accidens var. Hendersoni

Leaflets (15) 19-27, glabrous or often thinly pubescent above; peduncles 7-15 cm. long, mostly a little longer than the leaf; pod glabrous, the rather stout stipe 6-12 mm. long.—Collections: 34 (iii); representative: Constance & Rollins 2942 (NY, ORE, WS, WTU); Eastwood & Howell 1649, 1730 (CAS); L. F. Henderson 5972 (CAS, ORE); Ripley & Barneby 6700 (CAS, NY, RSA); Barneby & Howell 11, 486 (CAS, NY, POM, RSA).

Grassy and brushy hillsides, open woods, and oak thickets, on either volcanic or granitic bedrock, 700-4000 feet, locally plentiful but somewhat scattered, common in the upper Rogue River Valley in Jackson and immediately adjoining Josephine Counties, Oregon, north just into southeastern Douglas County (Jackson Creek, upper Umpqua River), and south along the Klamath River in northcentral Siskiyou County, California, thence rarely and interruptedly southward to the upper Trinity River in Trinity County (Weaverville) and to the Cascade foothills in Tehama and Butte Counties (Paynes Creek; Butte Creek).—Map No. 61.— Late April to July.

Astragalus accidens var. Hendersoni (Wats.) Jones, Rev. Astrag. 164, Pl. 39, 76. 1923, based on A. Hendersoni (Louis Forniquet Henderson, 1853-1942, sometime herbarium curator at ORE) Wats, in Proc. Amer. Acad. 22: 471. 1887 (non A. Hendersonii Baker, 1876). —"Open hillsides in the foothills of the Siskiyou Mountains, Josephine County, Oregon (L. F. Henderson, 1886)."—Holotypus, GH! isotypus, K!—A. Watsoni (Sereno Watson) Sheld. in Minn. Bot. Stud. 1: 23. 1894, a legitimate substitute. A. pacificus (of the Pacific) Sheld. in op. cit. 174. 1894, a superfluous substitute for the last, the supposed obstacle being A. Wat- sonianus (O. Kze.) Sheld. A. accidens var. pacificus (Sheld.) Jones, Rev. Astrag., Index. 1923, nomen. Hesperonix Watsoni (Sheld.) Rydb. in N. Amer. Fl. 24: 439. 1929.

Astragalus pruniformis (plum-shaped, of the pod) Jones in Proc. Calif. Acad. Sci. II, 5: 660. 1895.—"Butte County, Oregon [properly California], July, 1893, Mrs. Austin."—Holotypus, supposedly at US, not found there in 1960; isotypus (fragm.) POM!

Astragalus cymatodes (undulate, of the pod’s dorsal suture) Greene, Pittonia 3: 196, 1897.—"Somewhere in the upper part of the valley of the Sacramento in California."—No collector given, but the holotypus is labeled "Butte Creek, Butte County, N. California, Mrs. R. M. Austin," ND!

The var. Hendersoni is by far the more widely dispersed of the two varieties of the Rogue River milk-vetch, and for numbers of populations and of individuals the more important form of the species. Its extremely broken-up distribution in California carries suggestions of age, and I suspect that the nomenclaturally typical variety is the derived mutant.

The species proposed by Jones and Greene were described in ignorance of the genuine A. Hendersoni and have long been recognized as synonyms. The typi of A. pruniformis and A. cymatodes are apparently parts of the same collection.