Astragalus insularis var. insularis

Stems (0.3) 0.7-3 dm. long; leaflets rather distant, (7) 11-15 (17); pod 1-2.4 cm. long, 5-14 mm. in diameter, broadly turbinate at base, contracted into an erect or slightly incurved beak 2.5-4 mm. long, the ventral suture straight or nearly so, the dorsal one gibbous-convex, the funicular flange about 0.2-0.4 mm. wide.—Collections: 12 (o); representative: Palmer 685 (ND, NY, UC); Anthony 303 (ARIZ, DS, NY, POM, UC); J. N. Rose 16,151, 16,195, 16,904 (NY); Gentry 7576 (ARIZ, DS).

Washes, canyon beds, and dry sandy plains, sometimes in temporarily moist soil of ephemeral watercourses, 5-880 feet, apparently common locally on Cedros Island and on the mainland about San Bartolomé Bay, southern district of Baja California.—Map No. 116.—February to June.

Astragalus insularis (of Cedros Island) Kell, in Bull. Calif. Acad. Sci. 1: 6. 1884.— "Cedros Island... collected by D. J. A. Veatch."—Holotypus, collected June 4, 1877, CAS! —A. triflorus var. insularis (Kell.) Jones in Proc. Calif. Acad. Sci. II, 5: 637. 1895. Phaca insularis (Kell.) Rydb. in N. Amer. Fl. 24: 353. 1929.

Astragalus Pondii (Charles F. Pond, Lieutenant U. S. Navy) Greene, Pittonia 1: 288. 1889.—"San Bartolome Bay... in the month of March, 1889... on low plains around the southern shore of the Bay."—Holotypus, labeled in Greene’s hand "Astragalus Pondii Greene," but with no further data, ND!—A. insularis var. Pondii (Greene) Jones, Rev. Astrag. 104. 1923. Phaca Pondii (Greene) Rydb. in N. Amer. Fl. 24: 351. 1929.

The Cedros milk-vetch, var. insularis, is a pretty little astragalus, notable for the deep green color of the leaves, rather distant acute or subacute leaflets, tiny magenta-purple (when dry violet) flowers, and strongly asymmetric pod ventrally carinate by the prominent, nearly straight suture and speckled with anthocyanic pigment. The species was described from plants of diminutive stature which bore unusually small fruits, but more vigorous and leafy examples have since been obtained on Cedros (e.g., Haines & Hale in 1939, RSA) and these closely match the astragalus on the adjoining mainland described as A. Pondii Greene. Nevertheless, the insular race, however well nourished, has at least on the average smaller fruits than the populations around San Bartolome Bay. It should be noted that Phaca Pondii as interpreted by Rydberg (1929, p. 351) is in substance our var. quentinus described below.

The differential characters of A. piscinus, A. Vaseyi, and A. idrietorum, other species with small, purple flowers and bladdery fruits, which are native to Baja California and likely to be confused with A. insularis or its var. quentinus, are discussed under the heading of A. idrietorum.