Astragalus sanctorum Barneby, Brittonia, 1976

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

86. Astragalus sanctorum Barneby, Brittonia 28: 275. 1976

Type:— MEXICO, Baja California, TYPE: MEXICO. Baja California, SE slope of Banda Peak, Punta Banda , occasional in sage scrub, 250 m, 4 June 1975, Reid Moran 22395 (holotype: SD 283312 !; isotype: 00005840 NY!) .

Perennial. Stems, up to 55 cm long, erect or incurved or radially scattered minute strigose, the trichomes up to 0.5 mm long, straight, appressed. Stipules 2–5.5 mm long, semi-clasping, decurrent, not connate, acuminate to triangular. Leaves 6–12.5 cm long, leaflets 17–31, 11–17 mm long, lanceolate, lanceolate-oblong to elliptic, acute or obtuse apically, retuse and mucronate, somewhat bicolored. Peduncles 4.5–12 cm long; the racemes 1.5–4 cm long, flowers 9–15. Flowers white to whitish, turning ochroleucous when dry, occasionally with purple tones distally in banner and keel; the calyx 5–7.8 × 2.5–3.8 mm, strigose, the tube 3–4.3 mm long, campanulate, basally inequilaterous, the teeth 1.5–3.5 mm long, subulate; the; banner 14.4–17.8 × 6.5–8 mm, rhombic to oblanceolate recurved; the wings 12.3–14.2 × 2–2.6 mm, the claw 5–5.9 mm long, the blade 8.3–9.5 mm long, apically oblique, elliptic to obovate; the keel 9–11.5 × 2.3–3.2 mm, the claw 5–6 mm long, the blade 4.8–5.7 mm long, distally obliquely-obovate. Pod 2.3–3.4 × 0.8–1.3 cm, sessile, laceolate-oblong, wide oblong to ovate, inflated like a bladder, basally rounded or slightly narrowed, distally ending in a contracted triangular long beak up to 11 mm long, the valves thin, pale green or lightly purple tinted, papery, ochre with age, sub-diaphanous, septum absent ovules 23–43; seeds 2.4–2.8 mm long, mitten shaped, dark brown, with purple tones, smooth.

Distribution:— Endemic to Mexico, a restricted microendemic of Baja California, recorded only from Punta Banda (31°44’N, 116°43’W), approximately 18 km south of Ensenada, and La Bufadora (31°43’30”N, 116°43’24”) ( Fig. 24 ).

Habitat:— Scrublands; adjacent to coastal dunes; cliffs or plains; 40– 250 m.

Comments:— In this small area comprising the southern portion of the bay adjacent to Ensenada, several other Astragalus species can be associated with this vegetation near to coast including, A. didymocarpus var. didymocarpus , A. palmeri , A. pomonensis , A. sanctorum and A. trichopodus var. lonchus . Although all of them have widened or inflated bladdery pods, A. didymocarpus is easily distinguished by its minute (2–4 mm long), didymous pods, A. trichopodus var. lonchus is the only one of these remaining species with a stipitate (stipe 5–15 mm long) pod. Astragalus palmeri is easily separated by its purple to pink-shiny smaller flowers (banner 7–10.3 mm long, wings 6.7–9.2 mm long) and small (9–23 mm long) pods. Astragalus pomonensis and A. sanctorum have white petals, but A. pomonensis has larger leaflets (larger ones up to 30–37 mm) and more than twice the number of flowers per raceme (average 20–40).

Specimens examined:— BAJA CALIFORNIA: 11 May 1964, South slope of Banda Peak , Punta Bunda, R. Moran 15929 ( ENCB, JEPS, NY, TEX-LL) ; 9 May 1986, Punta Banda: SE of Peak and W of La Bufadora , R. F. Thorne 62035, J. Delgadillo ( NY) ; 4 June 1975, SE slope of Banda Peak, Punta Banda. Alt. 250 m, R. Moran 22395 ( CAS, MEXU, NY) ; 26 August 1976, Southeast slope of Banda Peak , Punta Banda, R. Moran 23715 ( SD) .

Figures

FIGURE 24. Map showing the distribution of Astragalus regiomontanus, A. rupertii, A. sabulonuum, A. sagitticarpus, and A. sanctorum in Mexico.