Astragalus emoryanus (Rydb.) Cory var. emoryanus, Rhodora

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

22. Astragalus emoryanus (Rydb.) Cory var. emoryanus, Rhodora 38(455): 406.1936

Type:— USA, Texas, El Paso , 1 January 1852, C. Wright s.n. (holotype (under Hamosa emoryana ): GH 00058725 digital image!; isotype: US 01108182 digital image!, NY 00011919 digital image!, MO 2196410 digital image!).

Hamosa emoryana Rydb., Bull. Torrey Bot. Club 54(4): 327. 1927.

Astragalus monterreyensis Rydb., Bull Torrey Bot. Club 54(4): 326. 1927.

Annual or bienal. Stems prostrate, creeping, with radial or sub-dradial growth; minute strigose or villous, the trichome up to 1 mm long, appressed. Stipules 1.5–5.5 mm long, triangular to ovate, glabrate o with scattered trichomes, semi or completely clasping, not connate. Leaves 1–8 cm long, leaflets 7–21, 2–14 mm long, nearly adjacent to each other, obovate, oblanceolate, retuse or truncate apically, pubescent adaxially and abaxially, only marginaly pubescent or subglabrate adaxially. Peduncles 1–10 cm long; the racemes 0.3–3.5 cm long, flowers 1–12. Flowers purple, reddishviolet with white center, dark pink to pink-purple; calyx 3.6–6 × 1.5–2.8 mm, pubescent with black and white trichomes, sometimes only black ones, the tube green-purple to purple, 1.9–3.5 mm long, the teeth 1.2–2.9 mm long, subulate; the banner 6–11.4 × 5.3–9.5 mm, recurved, obovate to spathulate, occasionaly deeply retuse at apex, with a striated, pale patch on the fold; the wings 5.1–10 × 1.1–3.4 mm, the claw 1.8–2.1 mm long, the blade 3.1–6.6 mm long, oblong to oblanceolate; the keel 4.5–6.7 × 1.9–2.5 mm, the claw 1.9–3.3 mm long, the blade 2.3–4 mm long, obovate. Pod 12–22 × 2–3.4 mm, spreading, pendulous to ascendant when himistrate, linear to oblong, triquetrous, curved or semicircular coiled, compressed, obtuse basally, cuspidate apically, laterally convex, dorsally openly sulcate, the valves slightly reticulate, papery, glabrate, light brown; septum complete, thence the pod bilocular or almost so, persistent in the plant until it opens; ovules 8–17; seeds 4-angular o mitten shape, olive-green, brown-light or brown, sometimes with purple tones, smooth.

Distribution:— Distributed in northern Mexico, from the northern end (and the only locality) of Chihuahua (Praxedis Guerrero), Coahuila (municipality of Múzquiz, and areas adjacent to Saltillo and Candela), north and northwest Nuevo Léon and also in northern Tamaulipas (Nuevo Laredo), in close proximity to Nuevo Leon and Laredo, Texas. Two varieties of this species are recognized. The other var. terlinguensis (Cory) Barneby is found locally in Texas. Also, in Texas ( USA) ( Fig. 6 ).

Habitat:— Gravelly, clayey, clay-gypsic, and calcareous soils; alluvial fans; roadside; disturbed scrubs; mesquitales; desert and crassicaul scrublands with creosote bush, acacia, mezquite,guapilla, maguey, prickle pear, granjeno, ocotillo; associations of mahogany, silktassel, juniper, ash, monilla, oak; 500–1600 m.

Comments:— Morphologically similar to A. nuttallianus , although in this later species the pods is pubescent (very rarely glabrous) and detach from the plant when opening.

Specimens examined:— CHIHUAHUA: 10 April 1983, Sierra San Ignacio (including and in the Sierra La Esperanza ), canyon 6.5 km SSW of Esperanza, R. D. Worthington 9745, R. Díaz ( NY, TEX) . COAHUILA:; 15 March 1973, 3 km N of Rancho Lechuguillal , M. C. Johston, T. L. Wendt, F. Chiang 10207 ( CAS, MEXU, TEXLL) ; 15 March 1973, Puerto de La Carroza (on Nuevo Leon border), M. C. Johnston 10199, T. L. Wendt, F. Chiang ( MEXU, NY) ; 28 February1946, Coahuila, About 40 km southwest of Monterrey , J. C. Johnson 16243 M. & F. A. Barkley ( NY) . NUEVO LEÓN: 20 March 1983, La Mesa (abandonada), Lampazos, O. Briones 1045, 1045 ( ANSM) , 13 March 1966, Carretera China-Monterrey, al lado de la Carretera, I- Domínguez G, s.n. ( ANSM) ; km 185, carr. Cuota Monterrey-Nuevo Laredo, 5 March 2004, E. Estrada et al. 15945 ( CFNL, CIIDIR, ENCB) ; 17 March 1973, Minas “Manto Blanco” y “Sabana Blanca”, just N of the Cañon de Potrerillos, M. C. Johnston 10248 E, T. L. Wendt, F. Chiang ( MEXU, NY, TEX) ; 16 March 1973, 3 km N of Rancho Lechuguillal , M. C. Johnston 10207, T.L. Wendt, F. Chiang ( CAS, NY, TEX-LL, MEXU) ; 22 March 1970, Ca. 34 mi south of Nuevo Laredo, N. D. Atwood 2053 ( NY) ; 22 March 1970, Ca. 34 miles south of Nuevo Laredo along hwy 85, L. C. Higgins 2674 ( ENCB, NY) ; 15 April 1946, Nuevo-Leon , Monterrey, J. Roybal 204 ( US) ; 3 February 2001, Rancho Santa maría ( CEMEX) , Mpio. Lampazos, J. J. Medellín n.n ( CFNL) ; October 1946, Mirador , near Monterrey, J. J. Roybal 669 ( MEXU) . TAMAULIPAS: 15 March 1988, San Carlos , Sierra de San Carlos, ca. 5 mi S of San Carlos, N side of Bufa El Diente, G. Nesom 6278, L. Hernández S, M. Martínez, J. Jiménez ( MEXU, TEX-LL) .

Figures

FIGURE 6. Map showing the distribution of Astragalus diphacus, A. douglasii var. glaberrimus, A. douglasii var. parishii, A. douglasii var. persitricuts, and A. emoryanus var. emoryanus in Mexico.