Astragalus purpusii M. E. Jones,

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

78. Astragalus purpusii M. E. Jones, Contr. W. Bot. 14: 34. 1912

Type:— MEXICO, Coahuila, Sierra de Parras , 9000 ft. alt., July 1910, Purpus 4582 (holotype: POM (not found at CCH1 or may be, it is RSA0003071 digital image!; isotype: GH00059430 digital image!).

Atelophragma purpusii (M. E. Jones) Rydb., Bull. Torrey Bot. Club 55: 164. 1928.

Perennial. Stems 5–27 cm long, diffuse, prostrate, procumbent or extended, forming radial colonies, minute strigose, the trichomes up to 0.7 mm long. Stipules 1–5 mm long, clasping, connate, constituting a loose sheath, attached for a half of 2/3 its length around the stem´s circumference. Leaves 1.5–5.8 cm long, leaflets 13–23, 1.5–6.4 mm long, oblong to obovate, truncate o retuse, adaxially glabrate. Peduncles 1.5–4.5 cm long; the racemes 0.5–1.6 cm long, flowers 7–22. Flowers purple, purple with white tones; the calyx 2.4–3.6 × 1.3–1.6 mm, strigose, the trichomes black, the tube 1.5–2.2 mm long, campanulate, the teeth 0.7–1.6 mm long, subulate, one pair shorter than the rest; the banner 4.5–7.6 × 3–5 mm, recurved, obovate to suborbicular, basally narrow, wide notched apically; the wings 4.1–5.7 × 0.9– 2 mm, the claw 1.5–2.2 mm long, the blade 2.8–4.5 mm long, oblanceolate to narrow obovate, oblique, incurved; the keel 3.5–4.3 × 1.3–1.5 mm, claw 1.5–2.2 mm long, the blade 2–2.5 mm long, obovate, apically oblique. Pod deflexed or spreading, 5–8 × 2.2–3.4 mm, sessile or subsessile, triquetrous, oblique, elliptic-trigonous to obovate-trigonous, base slightly cuneate, distally abruptly cuneate and contracted in a small, conic, 1 mm long beak, ventrally carinate, dorsally flattened or slightly sulcate, the valves minute strigose, papery, ochre, reticulate, septum complete or almost so; ovules 6–12; seeds 1.5–1.9 x 1–1.2 mm, mitten shaped, brown to pale brown, smooth, opaque.

Distribution:— Restricted to northeastern Mexico, southern Coahuila (Parras and Saltillo), central Nuevo León (Galeana) and northeastern Zacatecas (Concepción del Oro and Mazapil) ( Fig. 23).

Habitat:— In clayey, alluvial, stony and calcareous soils; open areas; wet gullies; dwarf oak shrubland; chaparral; pinyon pine forest with maguey; burned areas with juniper and madrone; subalpine meadow, dwarf pine scrubland; pine-juniper dwarf scrubland; cold conifer forest with fir, Douglas fir, pine, oak; pine forest; roadside; 2500–3650 m.

Comments:— Within the range of A. purpusii , another seventeen species of Astragalus can be found, but in spite of this rich diversity, many of those species are associated with shrublands of arid and semi-arid zones, few are associated with oak forests or cold coniferous forests communities obove 2,500 m in elevation. Among these species are A. hypoleucus , A. sanguineus , and A. legionensis . Out of these four species, A. hypoleucus can be easily distinguished by its dolabriform trichomes and A. sanguineus by its large red flowers. A legionensis is distinguished from A. purpusii by its racemes with fewer flowers (1–5), calyx almost twice the length (6.5–7.9 mm long), larger petals (banner 9.6–14 mm, wings 6.5–8.8 mm, the keel 7.4–8.4 mm) and oblong to elliptic (not triquetrous), 14–15 mm long, stipitate (stipe 2–2.5 mm long) pods.

Specimens examined:— COAHUILA: 12 May 1985, Sierra del Coahuilón, Arteaga , Coahuila G. B. Hinton 18830 ( CIIDIR, ENCB, MEXU); 14 July 2014, Sierra el Coahuilon , Coahuila J. A. Encina 3881, Z. A. Zamora, A. García M. ( ANSM); 27 May 1982, 6 km al SE de San Antonio de las Alazanas , Coahuila, J. A. Villarreal 1685 ( ANSM); 21 June 1976, McGill, Reeves and Nash , Coahuila, Road past San Antonio, ca. 30 mi E of jct. Rte. 57, McGill, Reeves, Nash, D. J. Pinkava P 13574 ( NY); 5 July 1941, On south slope of mountain, 24 kilo. northwest of Fraile, L. R. Stanford 417, K. L. Retherford, R. D. Northerall ( CAS, NY); 14 May 1973, Sierra de Parras ; footrail from W. part of town of Parras up to highest part of the Sierra, M. C. Johnston 10999, T. L. Wendt, F. Chiang (NY); 14 May 1973, Sierra de Parras ; footrail from W. part of town of Parras up to highest part of the Sierra, M. C. Johnston 1107 ( NY, TEX-LL) ; 6 August 1987, M. Vázquez 3813, J. A. Villarreal, M. A. Carranza ( CIIDIR, IEB) ; 3 March 1990, Cerro La Viga , Mpio. Arteaga, Coahuila, Hinton et al 20207 ( ENCB) . NUEVO LEÓN: 30 April 1989, Cerro el Potosí, Galeana , N.L, G. B. Hinton 19397 ( CIIDIR, ENCB, MEXU) ; 29 March 1988, A 500 m de la antena hacia el S, Cerro Potosí, Galeana , N.L, A. García 21 ( CIIDIR) ; 24 July 1977, Cerro Potosí, ca. 8 mi WNW of Galeana, C. Wells 217, 233, G. Nesom ( NY, TEX-LL) ; 7 July 1963, R. del Rosario, R. Segal, Nuevo Leon, Cerro Potosi. Near microwave tower, R. L. McGregor 255, L. J. Harms, A. J. Robinson, R. del Rosario, R. Segal ( NY) ; 17 July 1935, Las Canoas on Cerro Potosi, C. H. Muller 2195 ( NY) ; 31 May 1989, Cima del Cerro El Potosí, E. Estrada 1497, S. Favela ( CAS, MEXU, NY, TEX-LL) ; 16 September 1980, Ca. 110 mi S of Monterrey on upper road on east side of Cerro Potosi, J. S. Henrickson 18586 ( MEXU, NY, TEX-LL) ; 18 May 1982, Summit of Cerro Potosi, R. L. Dorr 2289, T. L. Atkins ( NY) ; 13 September 1960, Cerro Potosi; at northeast summit of mtn, J. H. Beaman 4458 ( NY) ; 24 July 1977, ca. 8 mi WNW of Galeana , NE face, C. Wells 229 ( NY) ; 1 July 1959, Cerro Potosi; top of mtn; in alpine meadow abundant, 3650 m J. H. Beaman 2669 ( NY) ; 2 July 1995, Cerro el Potosí, Galeana, N.L, Hinton et al. 25335 ( ANSM, TEX-LL) ; 7 July 1987, Cerro el Potosí, Galeana , N.L, S. González 4030 ( ANSM, CIIDIR) ; 30 April 1989, Cerro El Potosí, Mpio. Galeana , G. B. Hinton 19397 ( MEXU) ; 24 May 1974, Cerro Potosi, road from Galeana to microwave tower, between km 11 and the tower, east slope, T. Duncan 2394 ( ENCB) ; 2 May 1969, Cerro El Potosí, Mpio. Galeana, N.L., Hinton 17000 ( ENCB) ; 8 August 1970, Cerro El Potosí, Mpio. Galeana, Hinton 17293 ( ENCB) ; 20 July 1969, Cerro El Potosí, Mpio. Galeana, Hinton 17202 ( ENCB) ; 3 May 1987, Cerro EL Gallo, Mpio. Gtaleana, Hinton et al. 19121 ( ENCB) . ZACATECAS: 1 July 1973, 4 km. E. of Salaverna on the highway to Concepcion del Oro , M. C. Johnston 11549b ( NY, TEX-LL) ; 2 July 1993, 4 km. E. of Salaverna on the highway to Concepcion del Oro , M. C. Johnston, T. L. Wendt, F. Chiang 44558 ( CAS, MEXU) ; 2 July 1973, Sierra del Astillero (approached from southeast, from Tanque El Alto) M. C. Johnston 11555 ( NY) .