Monographs Details: Astragalus francisquitensis M.E.Jones
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(2): 597-1188.
Family:Fabaceae
Discussion:

326.  Astragalus francisquitensis

Delicate, diffuse, annual or perhaps sometimes biennial, with a slender taproot, sparsely strigulose with straight, appressed hairs up to 0.3-0.5 mm. long, the herbage green or in youth cinereous, the leaflets bicolored, yellowish-green and glabrous above; stems rarely simple and erect, usually 3-numerous, weakly ascending or prostrate, (0.2) 0.4-4 (6) dm. long, simple or branched (spurred) from base up to the first peduncle, floriferous upward from near or below the middle; stipules (1) 1.5-5 mm. long, the lowest ovate, early becoming papery- scarious, the upper ones longer, lanceolate or linear-acuminate, thinly herbaceous, green or purplish, not more than semiamplexicaul; leaves (1.5) 2-8.5 cm. long, slender-petioled, with (7) 13-21 narrowly elliptic-oblong or oblanceolate, or (in some lower leaves) oblong-obovate, obtuse to shallowly retuse, rather distant and sometimes scattered, flat, thin-textured leaflets 2-11 mm. long; peduncles ascending, slender or almost filiform, (2) 4-12 cm. long, mostly much longer than the leaf, the earliest ones sometimes shorter; racemes loosely (2) 4—10- flowered, the flowers ascending, the axis a little elongating, (0.5) 1-4 cm. long in fruit; bracts scarious, often purplish, broadly to narrowly lanceolate, 1-2 mm. long; pedicels ascending, straight or nearly so, at anthesis 0.2-0.7 mm., in fruit 0.7-1.2 mm. long; bracteoles 2, mostly minute or setaceous, sometimes 0; calyx 4.6-5.6 mm. long, strigulose with mixed black and white hairs, the slightly oblique disc 0.6-0.9 mm. deep, the tube 2.6-3.2 mm. long, ± 2 mm. in diameter, the lance-subulate or broadly lanceolate teeth 1.4—2.5 mm. long, the whole becoming scarious, ruptured, persistent with the pedicel; petals pale purple; banner recurved through ± 50°, ovate-cuneate or oblanceolate, deeply notched, 8.2-10 mm. long, 3.4-6 mm. wide; wings 8-9.3 mm. long, the claws 3-3.4 mm., the linear-oblong or -oblanceolate, straight or slightly incurved blades 5.2-6 mm. long, 1.3-2 mm. wide, obtuse, truncate-emarginate, or shallowly retuse at apex; keel 5.5-6.4 mm. long, the claws 3-3.4 mm., the half-obovate blades 2.8-3.7 mm. long, 1.7-2.2 mm. wide, abruptly incurved through 100-110° to the bluntly or exactly deltoid apex; anthers 0.4-0.5 mm. long; pod erect or narrowly ascending, sessile, linear- oblong, nearly straight, 1-1.5 cm. long, 2.1-2.8 mm. in diameter, obtuse at base, tapering distally into a very short cusp, compressed-triquetrous, with nearly flat lateral and narrowly but deeply grooved dorsal faces, carinate ventrally by the suture, the thin, green, sparsely strigulose valves becoming papery, stramineous, finely reticulate, inflexed as a complete septum ± 1 mm. wide, the beak unilocular; ovules 6-12; seeds ± 1.3-1.6 mm. long.—Collections: 9 (o); representative: Jones 24,175 (ARIZ, CAS, NY, POM, SMU, TEX); Gentry 4287 (GH, K, US), 4376 (DS, MO); Carter & Ferris 3358 (DS).

Stony glades in oak-pine forest and open ridges with piñon, oak, and Arbutus, 3500-6000 feet, mountains of the South District of Baja California: Sierra Gi- ganta; Cape region (Sierras de la Laguna, El Taste, de San Francisquito, de la Victoria).—Map No. 142.—October to March, following seasonal rains.

Astragalus francisquitensis (of San Francisquito) Jones in Proc. Calif. Acad. Sci. II, 5: 666. 1895.—"Brandegee, San Francisquito, Lower California, October 18, 1891."—Holotypus, collected probably in 1890, CAS! isotypus, UC!—Hamosa francisquitensis (Jones) Rydb. in N. Amer. Fl. 24: 429. 1929.

Astragalus lagunensis (of Sierra de la Laguna) Jones, Contrib. West. Bot. 8: 11. 1898 ("Lagunensis").—"Lower California, Brandegee."—Holotypus, collected in Sierra de la Laguna, January 23, 1890, UC! isotypus (fragm. + phototypus), POM!—A. francisquitensis var. lagunensis (Jones) Jones, op. cit. 10: 61. 1902.

The Laguna milk-vetch, A. francisquitensis, is the only astragalus known to occur in the mountains of Baja California below the latitude of Loreto, and is the only species of its type other than the much smaller-flowered, desert-dwelling A. Nuttallianus and A. acutirostris recorded from the Peninsula. Like annual astragali everywhere it varies greatly in vigor and stature, depending on amount and timing of rainfall; and although the plant may be capable of ripening at least some fruits after only a few weeks growth, it will persist, granted sufficient moisture, until the stems reach a length of 6 dm. and the taproot attains the thickness of a pencil beneath the crown. An occasional individual seems to persist over a dry period and flower a second time, consequently appearing biennial, but the majority of specimens examined are clearly fugitive annuals. The two species described by Jones correspond with extremes of stature, the typus of A. francisquitensis being relatively lush, with long stems and long, wide leaflets, while that of A. lagunensis is somewhat depauperate, condensed, and smaller-leaved. Specimens collected by Brandegee in Sierra El Taste in 1902 are quite intermediate, and it was probably after examining these that Jones reduced A. lagunensis to varietal rank. After his visit to the Laguna Mountains in March, 1928, Jones (Contrib. West. Bot. 15: 134. 1929) came to question the value of the variety, and there seems no doubt that Rydberg (1929, p. 429 ) appraised the two proposals correctly as exact synonyms.

Jones’s identification of A. francisquitensis with the perennial white-flowered A. ervoides (mentioned further under the latter heading) is patently absurd. In several respects it does resemble one species of continental Mexico, A. Gentryi, but is easily distinguished by its very obtuse keel-tip and regularly graduated petals. These two astragali are similar nevertheless in gross aspect and ecology and may be more closely akin than their position in different subsections suggests.