Astragalus oxyrhynchus Hemsl., Biol.

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

66. Astragalus oxyrhynchus Hemsl., Biol. Cent.- Amer., Bot. 1: 265. 1880

Type: — MEXICO, South Mexico, Tizapan , valley of Mexico, 18 June 1865, Bourgeau 329 (holotype:, Bourgeau 329 K 000478274 digital image!; isotype: US 00004239 digital image!, P 00585130 digital image!, P 00585131 digital image!, P 00585129 digital image!, P 00585132 digital image!, S 09-5206 digital image!) .

Tragacantha oxyrhy ncha Kuntze, Revis. Gen. Pl. 2: 947. 1891. — Hesperastragalus oxyrhynchus Rydb., Bull. Torrey Bot. Club 53: 165. 1926.

Astragalus angelinus M. E. Jones, Rev. N.-Amer. Astragalus 286. 1923.

Perennial. Stems up to 26 cm long, decumbent or distally ascendant, strigose, the trichomes appressed, short, up to 0.4 mm long. Stipules 1.5–5 mm long, semi-clasping, triangular, ovate to lanceolate, papery. Leaves 2.5–10.5 cm long, leaflets 11–23, 2–16 mm long, linear, oblong to oblanceolate, sometimes separated from each other by spaces of 6–10 mm, distally obtuse to retuse, adaxially glabrate. Peduncles 3.5–10.5 cm long, curved or straight; the racemes 1.5–8 cm long, dense, flowers 15–37. Flowers pendulous, purple, or the banner purple veined; the calyx 3.2–4.6 × 1.9–2.4 mm, strigose, with black o black y white mixed trichomes, the tube 1.9–2.6 mm long, campanulate, the teeth 1–2.2 mm long, subulate, dorsal pair longer than ventral one or vice versa; the banner 5.1–6.4 × 4.2–5.5 mm, recurved, ovate or fan-shaped, deeply retuse; the wings 5–6.6 × 1.5–2 mm, the claw 2.2–2.6 mm long, the blade 3.4–4.5 mm long, oblong to obovate, incurved or straight; the keel 5–5.6 × 2–2.2 mm, the claw 2.3–2.7 mm long, the blade 2.7–3.5 mm long, incurved, obovate. Pod 5–9 × 2.8–5 mm, sessile, pendulous, trigonous to obscurely trigonous, widened, oblong, ovate to ovate to semi-ovate, straight o strongly curved, basally rounded or truncate, distally abruptly contracted in a triangular beak, rarely tenuously or, ventrally carinate, shallowly compressed, flattened, sometimes dorsally openly sulcate toward the base, laterally widely rounded, the valves slightly fleshy or hard papery, ochre or black with age, markedly reticulate, adpressed, with tiny trichoms 0.15–0.2 mm long, septum complete, the pod thnce bilocular; ovules 8–14; seeds 2–2.6 mm long, mitten shape, brown purple-black.

Distribution:— Endemic to Mexico, in southern Hidalgo (Sierra de Guadalupe, south of Tula, Tepeji del Río and El Salto) in close proximity to the State of Mexico, and in the northern part of the state of Mexico (between Atlacomulco and Jilotepec) ( Fig. 20 ).

Habitat:— Calcareous soils, mountains with oak-pine forest, and coniferous forest, farmlands; 2073–2800 m.

Comments:— The northern area of the State of Mexico in close proximity to the southern region of Hidalgo harbors at least 11 Astragalus species. Three species ( A. oxyrhynchus , A. strigulosus and A. tolucanus ) are characterized by the presence of wide-ovate elliptic, oblong, ellipsoid, inflated but not bladder-like, not markedly and laterally flattened triquetrous or triquetrous-lanceolate pods. Astragalus strigulosus has white petals, elliptic or oblong-ellipsoid, 12–20 mm long, pedicellate pod, while A. tolucanus has pink-purple flowers and oblong-elliptic, 10–15 mm long, pedicellate pod. When individuals of A. oxyrhynchus are only in fruit they can be confused with A. micranthus , sympatric with it, both species have short pods, occasionally A. oxyrhynchus shows obscurely triquetrous pods, however, A. micranthus has short but always stipitate pods.

Specimens examined:—HIDALGO: 16 September 1903, El Salto, J. N. Rose 7090, J. H. Painter ( NY) : 20- VII/ 6 August 1896, Near Tula, C. G. Pringle 6404 ( ENCB, MEXU, NY, TEX-LL, US) ; 17 August 1902, El Salto, C. G. Pringle 9722 ( CAS, NY, US); 3 / 4 July 1905, Near Tula, J. N. Rose 8353, J. H. Painter, J. S. Rose ( US) ; 5 June 1992, 500 m al O de Santiago de Anaya , A. M. Soriano M. 167 ( ENCB, MEXU) . JALISCO: 7 July 1968, Puente de Ocotlán , L. M. de Puga 1455 ( IBUG) . MEXICO CITY: VII-1937, Lomas D. F., E. Lyonnet 1554 ( MEXU, US). MICHOACÁN : 2 August 2001, Sierra Chincua, M. G. Cornejo T. 263, G. Ibarra M. ( MEXU) . SAN LUIS POTOSÍ: 5 August 1970, Centro Ovino Juan Sarabia, Mpiop. Santo Domingo, A. Gómez ( ENCB) . STATE OF MEXICO: 15 August 1951, C. Cuatepec, S. Guadalupe, Valle Mex., E. Matuda 21222 ( NY) ; 17 July 1986, Villa del Carbón , San Luis Loma Alta, G. González M 1 ( MEXU) ; 23 June 1968, 7 km al N de Zumapngo , A. Arcos M. 71 ( ENCB) ; 23 July 1974, Cerro de La Cruz , 5 km al NW de Tepotzotlán, Rzedowski 31940 ( ENCB) ; 12 June 1981, Cerro Gord, Mpio. Otumba, M. Castilla 1256 , D. Tejero ( ENCB) ; 26 June 1977, Cerro Ahumada, 6 km al N de Huehuetoca, Rzedowski 35004 ( ENCB) ; 7 August 1966, 7 km al N de Huehuetoca , R. Cruz Cisneros 863 ( ENCB) ; 27 August 1966, 5 km al S de Tequisquiac , cerca del Cerro Jalpan, R. Cruz C. 1005 ( ENCB) ; 7 July 1968, cerca de la Presa El Capulín, Fraccionamiento La Herradura , Mpio. Huixquilucan, Rzedowski 25886 ( ENCB) ; 24 June 1966, R. Cruz C. 552 ( ENCB) ; 24 August 1969, 1 km al SE de Coacalco , E. Vilchis s.n. ( ENCB) ; 13 July 1967, Alrededores de la Presa La Concepción , Mpio, Tepozotlán, L. Hilerio A. 250 ( ENCB) ; 3 August 1976, Vertiente W del Cerro Sincoque ,, Mpio. Huehuetoca, Rzedowski 34341 ( ENCB) |; 24 June 1966, Aprox. 5 km al W de Atizapán , de Zaraoza, R. Cruz C. 777 ( ENCB) ; 1 August 1990, Campo Experimental Chapingo, San Bartolo, Mpio. Texcoco, A. Alcántar A. s.n. ( IEB) ; 23 June 1968, 2 km al W de San Miguel Tequixquiac , Rzedowski 25837 ( IEB) .

Figures

FIGURE 20. Map showing the distribution of Astragalus orcuttianus, A. oxyphysopsis, A. oxyphysus, and A. oxyrhynchus in Mexico.