Astragalus pringlei S. Watson,

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

75. Astragalus pringlei S. Watson, Proc. Amer. Acad. Arts 21: 449. 1886

Type:— MEXICO, Chihuahua, Plains near Chihuahua, 8 April 1885, Pringle 79 (holotype: H00059429 digital image!; isotype: E00383736 digital image!, US00001519 digital image!, UVMVT024923 digital image!, CAS0000806 digital image!, K000478269 digital image!, NY01268303! , F0058944F digital image!, MICH1107119 digital image!, P00585143 , BM000931687 digital image!, GOET004820 digital image!) .

Hamosa pringlei (S. Watson) Rydb., Bull. Torrey Bot. Club 54: 336. 1927.

Astragalus mexiae M. E. Jones, Contr. W. Bot. 18: 44. 1933.

Perennial. Stems several to many, up to 24 cm long, branched from base or a little higher, strigose, trichomes up to 0.5 mm long, straight, appressed. Stipules 1.5–3 mm long, semi-clasping, not connate, ovate to triangular. Leaves 1–4.5 cm long, leaflets 7–15, 1.5–6.2 mm long, elliptic to oblanceolate, obtuse, retuse to truncate, bicolored, adaxially darker and glabrate or glabrate adjacent to midvein, abaxially pubescent. Peduncles 0.5–5.5 cm long, erect or curved, decumbent with age; the racemes 0.5–4.5 cm long, flowers 3–12. Flowers pale purple, purple or also with lilac tones; the calyx 5.6–8.6 × 2.4–2.9 mm, strigose, trichomes white, the tube 4.1–5.7 mm long, campanulate to subcylindrical, somewhat basally inequilateral or gibbose, the teeth 1.5–2.8 mm long, subulate; the banner 12.1–16 × 3.4–4.3 mm, recurved, oblong to lanceolate, somewhat retuse; the wings 11.5–13.8 × 1.7–2.5 mm, the claw 4.7–5.6 mm long, the blade 7.2–8.7 mm long, linear to oblanceolate, straight or sometimes distally incurved; the keel 8.6–9.8 × 2–2.3 mm, the claw 4.7–5.8 mm long, the blade 4–4.6 mm long, elliptic or almost so, oblique. Pod 7–11.3 × 2.1–3.5 mm, sessile, humistrate with age, triquetrous, oblong, lanceolate, straight to somewhat curved, basally rounded, distally abruptly contracted in a short, triangular beak, ventrally carinate, laterally slightly convex, dorsally open and deeply sulcate, the valves green or with purple tones, strigose, finely reticulate, septum complete, the pod thence bilocular or almost so; ovules 11–15; seeds 1.9–2.3 mm long, mitten shaped, brown, sometimes with purple tones, shiny.

Distribution:— Endemic to Mexico. Northwest Mexico, local in Sonora (Yécora), in Chihuahua from northwest (Casas Grandes, through Galeana, Buenaventura, Madera, Namiquipa,Aldama, Gómez Farías, Chihuahua, Cuauhtémoc and La Junta), to the south to Balleza, local in Durango (Santiago Papasquiaro) ( Fig. 22 ).

Habitat:— High mountainous peaks and high palins and hills; stony, volcanic, white, light, alluvial, clayey, and compacted soil; grasslands; overgrazed areas; microphyllous scrubland; pine - oak forest; oak - juniper forest; oak fotrest with maguey and blue grama; mixed forests with oak, juniper, pine; oak-grassland; 1450–2286 m.

Comments:— The semi-arid and high mountain ranges regions in Chihuahua and Durango, comprising the A. pringlei distribution is assembled with the presence of other sixteen Astragalus species, but A. pringlei and three other species ( A. nuttallianus , A. quinqueflorus , and A. hypoxylus ) are characterized by purple, pink, lilac or white (with purple tones) petals and triquetrous sessile pods. For these only A. pringlei have relatively large leaflets (averaging 8–25 mm long). From de other species, none of them have the calyx greater than 7 mm or the banner larger than 11.2 mm long, and the wings larger than 11 mm. The pods of A. nuttallianus , A. pringlei and A. quinqueflorus are relatively similar in shape, consistency and size, but easily discernible with the flower size.

Specimens examined:—CHIHUAHUA: 8 April 1908 / 27 April 1908, Vicinity of Chihuahua , E. Palmer 89 ( NY, US); 1885, Near Chihuahua, T. C. Porter s.n. ( NY) ; 27 May 1929, Rancho Colorado, Y. Mexia 2563 ( JEPS) ; 3 May 1959, Vicinity of Rancho Ojito , D. S. Correll 21473, I. M. Johnston ( JEPS) ; 5 May 1959, in lower parte of Canyon along abandoned railroad, north of San Francisco del oro, D. S. Correll 21512, I. M. Johnston ( ENCB, JEPS) ; 18 August 1998, 2 km S of Santo Tomas in the Barrio San Ignacio, ca. ½ km S of Rio Papigochic , R. Spellenberg 12693, L. Brouillet, T. K. Todsen ( NY) ; 13 April 1984, Ca. 32 km SW of Matachic on road to Tesanachic, R. Spellenberg 7678, R. Soreng ( MEXU, NY) ; 13 May 1994, Alrededores de Chihuahua , E. Estrada 2484 ( NY) ; 8 April 1885, Plains near Chihuahua, C. G. Pringle 79 ( MEXU, NY) ; 26 October 1972, 6.0 mi W of Dolores Hidalgo just west of Los Hernandez , R. W. Spellenberg 2972 ( NY) ; 20 March 1984, Sierra Madre Occidental, 10½ miles southwest of the highway at San Jose de Babicora on a dirt road over the mountains to Highway 16 and Madera, A. C. Sanders 4734, West, Charlton, McIntosh, Vanway, Gilbeaut, Gould ( NY) ; 24 March 1984, 16.1 miles northwest of Balleza on the dirt road toward Rocheachi (60 miles) and Creel, A. C. Sanders 4784, West, Charlton, McIntosh, Vanway, Gilbeaut, & Gould ( NY) ; 1/ 8 April 1908, Vicinity of Miñaca , Chihuahua, J. N. Rose 11641 ( US). DURANGO : 25 March 1906 / 16 April 1906, Collected at Tepehuanes, E. Palmer 18 ( NY, US) & 26 ( JEPS) ; 5 May 1959, Vicinity of Rancho Ojito , D. S. Correl 21475, I. M. Johnston ( NY) ; 19 March 1983, 3–5 km al Oeste de La Soledad , 11 km NW Santiago Papasquiaro, R. C. Díaz 112 ( NY) ; 19 March 1983, 3–5 km al Oeste de La Soledad , 11 km NW Santiago Papasquiaro, R. Corral D. 112 ( MEXU) .

Figures

FIGURE 22. Map showing the distribution of Astragalus pomonensis, A. pomphocalyx, A. potosinus, A. pringlei, and A. prorifer in Mexico.