Astragalus purpusii M. E. Jones,

78. Astragalus purpusii M. E. Jones, View in CoL 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. View in CoL 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 P13574 ( 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) .