Astragalus prorifer

Caulescent annual or perhaps sometimes perennial of short duration flowering the first season, variable in stature, villosulous throughout or nearly so with spreading, widely ascending, or more narrowly incurved-ascending hairs up to 0.5-0.75 (0.9) mm. long, the stems and herbage canescent at first or permanently, the leaves sometimes greenish-cinereous in age, the leaflets pubescent on both sides or medially glabrescent above; stems incurved-ascending from the root-crown at soil-level, (0.7) 1-5.5 dm. long, in precociously flowering plants few and slender, simple, in more robust plants stout, numerous, and spurred or branched at several nodes preceding the first peduncle, floriferous from near or above the middle, stipules 2-6 mm. long, the lowest ones early becoming papery, strongly amplexicaul-decurrent but free, the upper ones firmer, ovate, broadly deltoid, or triangular- acuminate, thinly villousulous dorsally; leaves 3—11 cm. long, the lower ones shortly petioled, the upper subsessile, with 13—21 oblong, lance-oblong or -elliptic, or broadly lanceolate, obtuse, obtuse and mucronulate, or in some lower leaves emarginate and in some upper ones subacute, flat or loosely folded leaflets (3) 5-21 mm. long; peduncles stout or quite slender, 2.5-9 cm. long, mostly a little shorter than the leaf; racemes rather densely to quite openly 10—35-flowered, the flowers ascending at a wide angle or horizontal in age, the axis a little elongating, 4-10 cm. long in fruit; bracts submembranous, ovate or lance-acuminate, 1-2.5 mm. long; pedicels at anthesis 0.2-1 mm. long, in fruit somewhat thickened, arched outward, 0.5-1.4 mm. long, persistent; bracteoles 0-2; calyx 4-5.2 mm. long, densely villosulous like the herbage with white or partly black hairs, the subsymmetric disc 0.6-1 mm. deep, the campanulate tube 2.4-3.3 mm. long, 2-3 mm. in diameter, the subulate to broadly triangular-subulate teeth 1.5-2.3 mm. long, the whole becoming papery, ruptured, marcescent; petals pink-purple, the color apparently variable in depth; banner recurved through ±45° (further in withering), ovate- or flabellate-cuneate, openly notched, 7.6-9 mm. long, 4.4-7.6 mm. wide; wings 6.6-8 mm. long, the claws 2.5-2.8 mm, the oblanceolate or narrowly obovate, obtuse or (when broad) obscurely erose-emarginate blades 4.5-5.7 mm. long, 1.8-2.6 mm. wide, one more strongly incurved than the other; keel 6-7.6 mm. long, the claws 2.7-3.4 mm., the lunately elliptic blades 3.5—4.8 mm. long, 2-2.3 mm. wide, incurved through 90-100° to the triangular but ultimately obtuse, sometimes slightly porrect apex; anthers 0.45-0.6 mm. long; pod loosely ascending, widely spreading, or declined, sessile on and disjointing from an incipient gynophore 0.4—0.7 mm. long, obliquely ovoid-ellipsoid or ellipsoid, 1-2.3 cm. long, 4—10 mm. in diameter, little or moderately inflated but relatively firm-walled and when small scarcely bladdery, rounded or broadly obconic at base, contracted distally into an erect or slightly declined, triangular, shortly cuspidate, laterally compressed beak ± 2—4 mm. long, carinate ventrally by the prominent but filiform, gently convex or nearly straight suture, the dorsal suture more strongly or even gibbously convex, the thin, inwardly glabrous valves becoming papery, stramineous, finely reticulate, thinly to densely and canescently strigulose-villosulous with sinuously ascending, spreading, or subappressed hairs, not inflexed, the funicular flange obsolete or nearly so, not over 0.2 mm. wide; dehiscence apical, after falling; ovules 7-16; seeds orange-, purplish-, or chestnut- brown, smooth, dull or somewhat lustrous, 1.9-2.8 mm. long.—Collections: 10 (o); representative: Wiggins 9796, 9911 (DS); Brandegee (from San Luis) in 1889 (UC); Chambers 604, 604a (DS); Moran 11,076 (DS, NY).

Sandy flats, washes, and open slopes in pine-oak forest and xeric shrubbery, reported definitely from between 3500 and 6000 feet near its northern limit, perhaps lower and in desert environment southward, apparently local, known only from Sierra San Pedro Martir, Baja California, and south interruptedly to the northern extremity of the Southern District, lat. 27° 30'—31° 10' N.—Map No. 116.—April to June.

Astragalus prorifer (prowed. of the fruit’s prominent beak) Jones in Zoë 4: 275. 1893 ("proriferus").—"San Pedro Mártir, Lower California, May 5, 1893, Brandegee."—Cotypi, both labeled "type" in Jones’s hand, collected May 4 and May 16, 1893, the first from Santa Cruz Creek. UC! isotypus, labeled "April 16, 1893," NY!—Phaca prorifera (Jones) Rydb. in N. Amer. Fl. 24: 355. 1929.

Astragalus julianus (of San Julio) Jones in Proc. Calif. Acad. Sci. II. 5: 667. 1895. San Julio, Lower California, Brandegee, April 19, 1889."—Holotypus, UC! isotypi (fragments), NY, POM!

The prowed milk-vetch. A. prorifer, is closely related to A. Palmeri, perhaps not specifically distinct. The two species are almost identical in the form of the flowers and fruits and are subject to the same type and degree of variation in stature and duration of the plant, in density of vesture, and in size of the ripe pod. The extreme forms of A. prorifer are easily distinguished in practice by the villosulous or sometimes tomentulose pubescence of the leaves and stems: and when pods of the same size-range are compared, those of A. prorifer have fewer ovules or seeds. The material here referred to the prowed milk-vetch includes three superficially disparate types which deserve further analysis. The nomenclaturally typical phase of A. prorifer is a comparatively robust, canescently villous plant with dense racemes of 15-30 flowers borne on pedicels which are very short at anthesis. It was described by Jones as "shrubby at the base," but although probably perennial the root and caudex, if any, have not actually been collected. The typical pod is small (± 12-14 mm. long) and canescently villosulous with curly hairs. Brandegee’s plants, collected on the west slope of San Pedro Mártir in the neighborhood of Valladares and La Grulla, are closely matched by plants from Rancho La Suerte (Moran 11,076) and La Encinal (Wiggins 9796). The typus of A. julianus consists of several much more slender plants flowering in their first year. The racemes are looser and the flowers themselves fewer and slightly smaller, borne on pedicels at anthesis a trifle longer and developing into pods of the same size but less densely pubescent; their vesture of curled ascending hairs does not conceal the surface of the valves as in typical A. prorifer. The type- locality of A. julianus lies almost 250 miles southeastward along the Peninsula from San Pedro Martir, and it is easy to understand how Jones came to describe two species in the group. However, there is now a close match for A. julianus in plants collected at the south end of Sierra San Pedro Martir at Los Emes (Wiggins 9711), and a collection in flower from an intermediate station at San Luis (lat. 28° 25' N.) is similar except for the more thinly hirsutulous, mostly greenish herbage. What I take to be a third variant of A. prorifer is known from the precipitous west slope of San Pedro Mártir in Canon del Diablo (Chambers 604, 604a). Here the vesture of leaves and stems is ascending rather than spreading and the pod is larger than in the foregoing variants, up to 22 mm. long and up to 14-16-ovulate. These plants resemble A. Palmeri in almost all characters except the loose vesture and might be interpreted as forming a connecting link with that species, which reaches its known southern limit of dispersal at the north end of San Pedro Mártir.

According to Jones A. prorifer should differ from A. julianus in having the fruits borne in spikes rather than racemes, in its woolly rather than silky pubescence, and in dark purple rather than whitish flowers. The pedicels of typical A. prorifer are short at anthesis but become evident at the fruiting stage, so that the inflorescence is never a true spike and not fundamentally different from the looser, fewer-flowered one of A. julianus. The flowers of A. julianus were originally described as white tipped with purple, and in similar modern collections are clearly purplish. The difference in pubescence is one of density and not due to any fundamental difference in the quality of the hairs. Now that the geographical separation has broken down so completely, I feel confident that A. prorifer and A. julianus represent no more than two variants of one variable species.

Little difficulty should be encountered in recognizing A. prorifer, the only member of its section in Baja California characterized by villosulous leaves. On both slopes of San Pedro Mártir the species is sympatric with A. gruinus, but this is distinguished by its somewhat larger flowers, more numerous (24-26, not 7-16) ovules, and eventually by its larger, proportionately plumper, greatly swollen fruits which remain attached to the receptacle when ripe and fall to the ground together with the disjointing pedicels.