Astragalus crotalariae (Benth.)

Castillón, Eduardo Estrada, Quintanilla, José Ángel Villarreal, Delgado-Salinas, Alfonso & Rebman, Jon P., 2023, The genus Astragalus (Leguminosae: Papilionoideae: Galegeae) in Mexico, Phytotaxa 586 (1), pp. 1921-1935 : 1921-1935

17. Astragalus crotalariae (Benth.) A. Gray, Proc. Amer. Acad. Arts 6: 216. 1864

Type:— USA, California, Monterey, California, Coulter 436 K (holotype K) not seen.

Phaca crotalariae Benth., Pl. Hartw. 307. 1848. — Tragacantha crotalariae (Benth.) Kuntze, Rev. Gen. 2: 944. 1891.

Astragalus limatus E. Sheld. , Minnesota Bot. Stud. 1(3): 126–127. 1894. A. preussii A. Gray var. limatus (E. Sheld.) Jeps., Man. Fl. Pl. Calif. 566. 1925.

Perennial, hard, with bad smell. Stems up to 70 cm long, striate, hollow, green-yellowish, strigose to pilose, the trichomes up to 1.3 mm long. Stipules 3.7–13 mm long, ovate, wider than longer, clasping to semi-clasping, not connate. Leaves 5–16 cm long, the leaflets 5–17, 5–36 mm long, elliptic, oblong, obovate to spathulate, rarely suborbicular, retuse, glabrate or scarcely pilose adaxially. Peduncles, 5–17.5 cm long, straight, hard; the racemes 2–9 cm long, flowers 10–27, ascendant. Flowers rose, purple, magenta, turning violet when dry, rarely totally white; the calyx 7.5–12.4 × 3.5–6.7 mm, papery, strigose or pilose, the trichome black and white, the tube campanulate to subcylindrical, 6.3–6.7 mm long, reddish or with reddish-purple tones, the teeth triangular to subulate, 1.2–2.7 mm long; the banner 21–28 × 8–14 mm, rhombic to spathulate, entire o slightly emarginated apically; the wings 19–25 mm × 3–5 mm, linear to oblong, to oblong-obovate, the claw 8.5–11.4 mm long, the blade 10.6–15 mm long; the keel 17.3–22 × 3–5.2 mm, incurved, the claw 8.6–11.4 mm long, the blade 8.6–11 mm long. Pod estipitate, the stipe 1–1.4 mm long, the body 2–3 × 1–1.6 cm, spread or ascendant, somewhat compressed laterally, elliptic, ovoid, abruptly or gradually narrowed at base, inflated but somewhat leathery, the apex with a curved ot straight short beak, the valves sparsely or densely strigose, yellowish, light-brown, brown to dark-brown, lightly reticulate, septum absent; ovules 24–38; seeds 3–4.4 mm long, brown or brown-purple, opaque.

Distribution:— In Mexico, known only in the extreme north of the state of Baja California, adjacent to the border with the USA. New River (apparently translated from Río Nuevo, river located near Mexicali). Also present in Arizona and California ( USA) ( Fig. 5 ).

Habitat:— Rare, only one record, registered in scrubland areas. Also in Arizona and California ( USA).

Comments:— A. crotalariae is distinguished by its large flowers (23–28 mm long) and restricted distribution in Mexico.

Specimens examined:— BAJA CALIFORNIA: 2 April 1905, Plains of New River , T. MacDougal 223 ( NY) .

Figures

FIGURE 5. Map showing the distribution of Astragalus crotalariae, A. daleae, A. coccineus, A. didymocarpus var. didymarpus, A. didymocarpus var. dispermus, and A. didymocarpus var. obispoensis in Mexico.