Astragalus anemophilus

Diffuse, trailing, or somewhat bushy-branching perennials, with a long taproot and at length basally indurated stems (often submerged in shifting sands), densely and softly tomentulose throughout with fine, curly, entangled hairs up to 0.6 mm. together with a very few longer, almost straight, ascending hairs up to 1 mm. long, the stems and herbage white, the leaflets sometimes becoming greenish- gray in age; stems about 2.5-3.5 dm. long, freely branching or spurred toward the base, flexuous distally; stipules thinly herbaceous becoming papery, 2.5-8 mm. long, all amplexicaul and connate through ± ? of their length into a dorsally tomentulose, sometimes finally ruptured sheath, with short, broadly triangular-acuminate, erect blades; leaves 4-9 cm. long, shortly petioled or the uppermost sub- sessile, with 19-35 (37) broadly elliptic, broadly obovate, or suborbicular, very obtuse or subretuse, flat or loosely folded leaflets (2) 4-14 mm. long; peduncles stout, incurved-ascending, 8-15 cm. long, commonly weighed down by the fruit; racemes rather closely 15-23-flowered, the flowers loosely ascending or spreading, the axis a little elongating, 3-7 cm. long in fruit; bracts papery-membranous, ovate, acute, 1.1-2.1 mm. long; pedicels ascending, straight or a trifle arched outward, at anthesis 1-1.5 mm., in fruit thickened, persistent, 2-3 mm. long; bracteoles rudimentary or 0; calyx 6-6.5 mm. long, tomentulose like the leaves but somewhat less densely so, the strongly oblique or subsymmetric disc 0.9-1.5 mm. deep, the campanulate or somewhat ovoid-campanulate, purple-tinged tube 4.3-5.2 mm. long, 3.5-4.1 mm. in diameter, the triangular or broadly triangular-subulate teeth 0.8-1.5 mm. long, the whole becoming papery, ruptured, marcescent; petals ochroleucous; banner abruptly recurved through ± 80°, 11.5-12.7 mm. long, the short, broadly cuneate claw expanded into a rhombic-ovate or -suborbicular, notched blade 6.8-8.8 mm. wide; wings as long or a trifle longer than the banner, 11.5-12.8 mm. long, the claws 5.2-6 mm., the broadly oblong, obtuse, nearly straight blades 7-8.6 mm. long, 2.8-3 mm. wide; keel 10-11 mm. long, the claws 5-6.2 mm., the half-obovate blades 5.4—5.7 mm. long, 2.7-3.2 mm. wide, abruptly incurved through 90—95° to the bluntly triangular, sometimes subporrect apex; anthers 0.55-0.85 mm. long; pod spreading or loosely ascending, sessile, obliquely ovoid, bladdery-inflated, (2.7) 3-4 cm. long, 1.5-2.2 (or when pressed seemingly up to 2.7) cm. in diameter, broadly obconic at base, contracted distally into a short, triangular, laterally compressed beak, shallowly sulcate ventrally and obscurely so dorsally, the ventral suture nearly straight or much less strongly convex than the dorsal one, the thin, pale green often purple-spotted but unmottled valves tomentulose with extremely fine, curly hairs, becoming stramineous, papery, delicately reticulate, not inflexed, the funicular flange ± 0.5-0.7 mm. wide; ovules 32-40; seeds brown, smooth but dull, 2.3—2.6 mm. long.—Collections: 7 (i); representative: Orcutt 1325 (NY); Raven, Mathias & Turner 12,418 (CAS); Harbison & Higgins (from Colonia Garcia) in 1953 (RSA); Wiggins 11,282 (DS), 11,884 (DS, UC).

Mobile and partly stabilized dunes below 30 feet, locally abundant around San Quintín Bay, Baja California.—Map No. 109.—December to May, probably intermittently through the year.

Astragalus anemophilus (wind-loving, "exposed to the incessant winds of that point of the coast") Greene in Bull. Calif. Acad. Sci. 1: 186. 1885.—"Cape San Quintín, Lower California, May 10, 1885."—Holotypus, collected by E. L. Greene, CAS! isotypi, DS, ND, NY!—A. Crotalariae var. anemophilus (Greene) Jones, Contrib. West. Bot. 10: 59. 1902.

Phaca vestita (clothed, of the dense tomentulose vesture) Bth., Bot. Sulphur 13. 1844. "Bay of Magdalena, and San Quintin."—Holotypus, collected by Hinds, doubtless at San Quintln and not at Magdalena Bay, K!—Astragalus vestitus (Bth.) Wats., Bibl. Ind. 202. 1878 (non Bss. & Heldr., 1849). Tragacantha vestita (Bth.) O. Kze., Rev. Gen. 949. 1891.

The San Quintín milk-vetch is an exceptionally handsome species, notable for the dense, soft tomentum clothing the whole plant up to the rather small, whitish flowers, the many short leaflets of broad outline, and the large size of the purple-dotted (in general effect pink-cheeked), rather firmly papery, but greatly swollen pods. The plants occur in quantity over the barrier dunes along the ocean near San Quintín and at Socorro, where they form entangling masses of white stems and foliage often partly engulfed by movements of the sand. The species was first collected by Hinds in flower only, but Phaca vestita is readily recognizable from Bentham’s description of the vesture, connate stipules, and other features. The attribution of P. vestita to Magdalena Bay as well as San Quintín is almost certainly incorrect, however. It is known that some of Hinds’ and Sinclair’s labels were transposed, and the dune astragalus common (and the only one of its sort since encountered) at Magdalena Bay is A. magdalenae, also first collected on the cruise of the "Sulphur" and described as Phaca candidissima by Bentham in the same work. The more southern plant differs greatly in its appressed, satiny pubescence, free stipules, and differently proportioned, purple flowers. Except for the closely related A. Harbisonii mentioned below, A. anemophilus is the only perennial astragalus with sessile and inflated fruit known from the west coast of northern Baja California.

The species was recorded by Rydberg (1929, p. 349) with a note of doubt from San Miguel Island off the coast of Alta California; but the only specimen so annotated in his hand at NY is an isotypus of A. miguelensis, a fact which serves to emphasize the close relationship between these two maritime vetches. The characters contrasted in the key to the section are not especially strong ones, but the average specimen of A. miguelensis is so easily distinguished by its smaller pod, more often than not narrowly septiferous within, and the more nearly ordinary graduation of the petals, that it seems reasonable to maintain them as specifically distinct.