Astragalus hartwegii Benth., Pl. Hartw.

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

39. Astragalus hartwegii Benth., Pl. Hartw. 10. 1839

Type:— MEXICO, Aguascalientes, 1839, Hartweg 53 (holotype: K000478283 digital image!; isotype: P00585370 digital image!, E00383728 digital image!, LD1001510 digital image!

Hamosa hartwegii (Benth.) Rydb., Bull. Torrey Bot. Club 54: 333. 1927.— Tragacantha hartwegii (Benth.) Kuntze, Revis. Gen. Pl. 2: 945. 1891.

Hamosa hidalgensis Rydb, Bull. Torrey Bot. Club 54: 333. 1927.

Perennial. Stems up to 40 cm long, suberect, semi-prostrate, widely diffuse, minute strigose, trichomes up to 0.5 mm long, appressed or subappressed. Stipules 1–4 mm long, the lowest clasping, free, the rest semi-clasping, not connate, triangular, triangular-lanceolate to lanceolate. Leaves 2–15 cm long, leaflets 15–29, 3–21 mm long, linear, oblong, elliptic, obtuse or acute, rarely obovate and retuse, glabrate o softly pubescent adaxially. Peduncles 4–21 cm long, ascendant, straight or curved; largest racemes 4–15.5 cm long, dense when young, turning lax with age, flowers 15–62, soon deflexed. Flowers purple, at least the banner, turning pale-blue when dry or white to white-greenish; the calyx 3.2–4.8 × 1.7–2.5 mm, strigose, trichomes white or black, the tube 2.2–3.4 mm long, campanulate, basally inequilateorus, truncate, inequilateral at the base; the teeth 1–1.4 mm long, subulate to triangular; the banner 7–9.2 × 3.5–5.4 mm, ovate, narrow basally; wings 6.6–8.6 × 1.2–1.7 mm, the claw 2.5–3.2 mm long, the blade 4.5–6.3 mm long, incurved, lanceolate, distally obtuse; the keel 5.2–6.3 × 1.9–2.2 mm, the claw 2.5–3 mm long, the blade 3.1–4.3 mm long, semi-obovate. Pod 1–1.5 × 0.2–0.24 cm, sessile, deflexed, lanceolate, linear to oblong, straight o strongly incurved, triquetrous, basally rounded, distally narrow in a subulate beak, laterally compressed, ventrally carinate, dorsally widely sulcate, lateral faces straight to slightly rounded, the valves soft strigose, papery, ochre or turning black with age, soflty reticulate, septum complete, thence the pod bilocular; ovules 14–19; seeds 1.2–1.5 mm long, mitt-shaped, smooth, brown, green-olive, sometimes with purple spots.

Distribution:— Endemic to Mexico. From central (Cuauhtémoc, Guerrero, Carretas, Colonia Diaz), and northeastern (Nazareno, Chocolate and Zaragoza) mountains of Chihuahua, through central-eastern ( Guadalupe Victoria, Carlos Real, Morcillo, Durango, Nombre de Dios and Amado Nervo) and southern (Suchil, Mezquital, Temoaya, Baluarte, Ollitas, Amoles y Los Charco) Durango, southern Coahuila (Parras), western (Sombrerete y Chalchihuites) Zatacecas, in close proximity to Durango, northwestern (Charcas) and central (Ciudad del Maíz, Río Verde) San Luis Potosí, southern Aguascalientes to central-eastern Guanajuato ( Fig. 11 ).

Habitat:— Alluvial, yellow, white, clayey, deep, and stony soil; basalt; rocky slopes; river banks; plains with grasslands; open pastures along moist draw; halophytic grasslands; halophytic grasslands with masquite and grasses; dry grasslands; juniper-grassland; acacia - prickle pear associations; conifer forest, oak-pine forest; oak forest; stream banks; sometimes as weed in cultivated areas; arid xerophytic scrublands; riparian vegetation with pine douglas fir, oak, cypresss; 1000–2700 m.

Comments:— A sympatric and morphologically similar species to A. vaccarum , but it has a symmetrical calyx at the base and a shorter pod (6–12 mm long). In herbarium samples, A. hartwegii is frequently confused with A. ervoides . It is possible to recognize and distinguish them based on the attachment of the pod to the receptacle. In A. ervoides the pod is elevated from the receptacle by a stipe (0.5–1.5 mm long), even when small (0.5 mm long), the stipe is always present, but also can be discerned by inflorescences size, because, the peduncles (3–9 cm long) and the racemes (up to 4 cm long) of A. ervoides are shorter. When the plant is flowering and lacking fruits, A. hartwegii and A. micranthus are physiognomically very similar, but the most obvious characteristics to distinguish them are the stipules; A. micranthus has connate ones (at least the basal ones). When fruiting, the pods of A. micranthus are persistent on the receptacle until dehiscence, they have also thinner texture, almost straight or less curved, and more trigonous than triquetrous, the compression is less pronounced, with more rounded lateral faces, and proportionally fewer ovules, 8–14.

Specimens examined:—CHIHUAHUA: 29 July 1985, Los Arcos (Aprox. 11 Km. de La Guajolota ), I. Solís 74 ( CIIDIR, MEXU) ; 20–21 September 1899, At Colonia Diaz, E. W. Nelson 6448 ( NY) ; 3 August 1959, 12 miles W of Cuauhtemoc, 78 miles W of Chihuahua , F. W. Gould 8733 ( JEPS) ; 9 September 1887, River bluffs, Guerrero, E. Palmer 1217 ( NY) ; 9 September 1887, River bluffs, Guerrero, C. G. Pringle 1217 ( NY, US) ; 27 August 1887, River bluffs, Guerrero, C. G. Pringle 1217 ( NY) . COAHUILA: 1/10-1880, San Lorenzo de Laguna and vicinity22 to 27 leagues southwest from Parras, E. Palmer 235 ( US). DURANGO : 13 July 1990, 56 km al sur por el camino a La Flor, Mpio 005, A. García 4458, S. González ( CIIDIR) ; 16 July 1981, Villa Unión , 3.5 km al N de La Cieneguilla, S. González 1732 ( ANSM, CIIDIR, IEB, MEXU, NY) ; 13 July 1990, 56 km al S, por el camino a La Flor, A. García 4458, S. González, R. Spellenberg ( ANSM, CIIDIR, ENCB, IBUG, IEB, MEXU) ; 22 August 1995, Reserva de La Michiliam Ciénega de Los Caballos , Mpio. Súchil, J. A. Villarreal 8208, M. A. Carranza, A. García A. ( ANSM, CIIDIR, IEB, TEX-LL) ; 26 July 1982, Along hwy. Mex . 40, 3 km. SW of turnoff to Carlos Real, 32 km, G. Diggs 3040, M. Nee ( MEXU, NY) ; 25 July 1958, 19 miles northeast of Durango, route #31, D. S. Correll 20167, I. M. Johnston ( NY, MEXU, SD, TEX-LL) ; 7 September 1989, Mesa de Canalitas , A. A. Paredes 839 ( MEXU) ; 24 July 1990, Ca. 47 air km SSW of Vicente Guerrero on road to Las Margaritas, 6 rd km on main road S of the headquarters area called “Piedra Herrada of the Reserva de la Biosfera “La Michilia”, at km. marker 60, R. Spellenberg 10311, S. González ( MEXU, NY) ; 25 July 5 August 1906, Otinapa, E. Palmer 395 ( NY) ; IV November 1898, Collected at the city of Durango and vicinity, E. Palmer 290 ( NY) ; 19 August 1959, 10 miles south-east of Durango, U. T. Waterfall 15520 ( NY) ; 30 June 1984, 2 Km al W de Lechería, carr. a La Ciudad, P. Tenorio 6059, T. P. Ramomoorthy ( MEXU, NY) ; 30 July 1990, Km. 3 de la carretera Santiago, A. Benítez P. 1803 ( IEB, MEXU) ; GUANAJUATO: 4 August 1989, Guanajuato, E. Ventura 6978, E. López ( ENCB, IEB, MEXU) ; 26 October 1972, On the highway between Guanajuato and Dolores Hidalgo, 13.5 mi. w of Dolores Hidalgo, R. Spellenberg 2970 ( NY) 28 June 1982, El Madroño 64 km, al NW de Durango, P. Tenorio L. 682,C. Romero de T., R. Hernández ( MEXU) ; 30 July 1991, Guanajuato, E. Ventura 9355, E. T. López ( IEB, MEXU) ; 28 August 1994, 12 km al SW de Nuevo Valle de Moreno, Mpio. León, Rzedowski 52386 ( IEB) ; 24 September 1994, Sobre la carretera a San José, Rzedowski 52637 ( IEB, MEXU) ; 2 August 1990, 10 Km de Canelas , camno a Cuevecillas, A. Benitez 1763 ( MEXU) ; 7 September 1989, Mesa de Canalitas , A. Benitez P. 839 ( MEXU) ; 30 April 1998, La Mesa de los Hernández. Poblado de la Mesa, J. Martínez C. 973 ( MEXU) ; 28 August 1997, la Mesa de los Hernández, M. Cano M. 65 ( MEXU) ; 24 September 1994, Sobre la carretera a San José, Rzedowski 52637 ( IEB, MEXU) . JALISCO: 2 August 1987, R. Ornelas U. 896 ( IBUG) ; 3 August 1999, Papas de Arriba , aprox. 4.5 km al NO de Guadalupe Victoria, Mpio. Ojuelos de Jalisco, P. Carrillo R., M. Harker 836 ( IEB) ; 2 August 1987, 3 km. en la Desv. hacia el Novillo carret. a Lagos de Moreno a Ojuelos en campos de cultivo de maíz, M. L. Román M. 835 ( MEXU) ; 24 September 1994; 7 September 1973, La Calera , 11 km al N de Teocaltiche, Mpio. Teocaltiche, L. M. Villarreal 5192 ( ENCB) . MICHOACÁN: 31 July 1992, Cerro La Cinsinillas , J. M. Escobedo 2381 ( ENCB, IEB, MEXU) ; 5 July 1986, aprox. 2 km al NO de La Concepción, Mpio. Morelia , V. M. Huerta 557 ( IEB) ; 15 June 1986, Puerto de Los Tepetates , arox. 1 km al SE de Huajumbaro, Mpio. Cd. Hidalgo, S. Zamudio R. 3915 ( IEB) ; 5 August 2000, Estación Chincua , Reserva de la Biósfera Mariposa Monarca, (alrededores del vivero forestal), M. G. Cornejo T. 33 ( IEB, MEXU) ; 30 July 1984, aprox. 1 km al S de Francsico Villa, Mpio. Zinapécuaro , M. Díaz J. 209 ( IEB) ; PUEBLA: 12 August 1987, Camino lado sur Santiago Xalitzintla, Mpiop. Cholula, F. Ramos N. 2657 ( IEB) . SAN LUIS POTOSÍ: 16 September 1967, 9 km al E of Rioverde , sobre la carretera a Rayón, J. Rzedowski 24780, M. E. Sánchez, R. Cruz ( ENCB, NY) ; 31 May 1971, Just off Mex. 70, 0.4 mi. e. of e. edge of Rio Verde , D. B. Ward 7795 ( NY) ; 10 September 1960, Ciudad del Maíz , ± 4 km al SW de Tablas, F. Takaki 448 ( ENCB, NY) ; 12 September 1960, Rioverde , De San Bartolo a Progreso, F. Takaki 378 ( NY) ; 23 June 1962, La Gavia, A. Gómez 697 ( NY) ; V September 1911, Minas de San Rafael , C. A. Purpus 5195 ( NY) ; 2 June 1904 / 8 June 194, Media Luna, near Rio Verde , E. Palmer 81 ( NY) ; 14 May 1955, San Bartolo, cerca de la Laguneta, Mpio. Río Verde , Rzedowski 5818 ( ENCB) . SONORA: n.d., Los Nogales, E. K. Smith s.n. ( NY) . ZACATECAS: 8 August 1971, Along Mexico Highway 49 below San Francisco los Flores, a small village south of the highway about 8.5 miles northwest of Sombrerete, the road to San Francisco being opposite that to Providencia, about 1 mile south of Highway 49, J. L. Reveal 2672, W. J. Hees, W. Kiger ( NY, US) ; 16 October 1965, S. end of Sierra de Papanton east of El Calabazal , H. D. Ripley 14154, R. C. Barneby ( MEXU, NY, US) .

Figures

FIGURE 11. Map showing the distribution of Astragalus hartmanii, A. hartwegii, A. helleri, A. hidalgensis var. hidalgensis, and A. hidalgensis var. protensus in Mexico.