The genus Astragalus (Leguminosae: Papilionoideae: Galegeae) in Mexico Author Castillón, Eduardo Estrada 0000-0003-1061-9862 Universidad Autónoma de Nuevo León, Facultad de Ciencias Forestales, A. P. 41, 67700, Linares, Nuevo León, Mexico aeduardoestradac@prodigy.net.mx Author Quintanilla, José Ángel Villarreal 0000-0001-9672-8693 Universidad Autónoma Agraria Antonio Narro, Departamento de Botánica, Saltillo, Coahuila, Mexico javillarreal00@yahoo.com Author Delgado-Salinas, Alfonso 0000-0002-9322-9968 Universidad Nacional Autónoma de México, Instituto de Biología, 21068 adelgado@ib.unam.mx Author Rebman, Jon P. 0000-0002-4150-7356 San Diego Natural History Museum, P. O. Box 121390, San Diego, California, 92112 jrebman@sdnhm.org text Phytotaxa 2023 2023-03-07 586 1 1921 1935 http://dx.doi.org/10.11646/phytotaxa.586.1.1 journal article 10.11646/phytotaxa.586.1.1 1179-3163 7703999 54. Astragalus lyonnetii Barneby, Mem. New York Bot. Gard. 13(1): 162. 1964 Type:— MEXICO , Morelos , Toro , 9000–9800 feet , 5 August 1924 , G. L. Fisher 260 ( holotype : US00004205 digital image!) . Perennial . Stems up to 30 cm long, decumbent or suberect, strigose and pilose, the trichomes up to 0.6 mm long, appressed, subappressed or completely straight. Stipules 1–8 mm long, the lowest ones connate and amplexicual, bidentate, the upper ones connate, attached to the middle of its length or less, pubescent. Leaves 3–7 cm long, leaflets 9–27, 2–12.3 mm long, linear, oblong to oblanceolate, distally truncate o retuse, adaxially glabrate. Pedunucles 3–11 cm long, almost always with black trichomes, rarely few with ones; the racemes up to 2.5 cm long, dense, with black trichomes, flowers 11–20. Flowers ochroleucous, turning pale yellow when drying, ascending, but deflexed with age; the calyx 5.2–7.4 × 2.2–2.8 mm , pilose, with black trichomes, sometimes mixed with few white trichomes, the tube 2.9–4.4 mm long, campanulate, the teeth 2.3–3.8 mm long, subulate; the banner 10–12.5 × 4.1–5.2 mm , rhombic, elliptic to oblanceolate, slightly retuse; the wings 9.5–9.8 × 1.6–2 mm , the claw 4–4.6 mm long, the blade 6.6–7.1 mm long, linear to oblanceolate; the keel 7.7–8.7 × 2.1–2.4 mm , the claw 4–4.7 mm long, the blade 4.5–5 mm long, obovate, abruptly incurved. Pod reflexed, stipitate (stipe 2.8–3.1 mm long), the body oblong to elliptic, 10–14.3 × 3.2–3.9 mm , obtusely triquetrous, basally cuneate, distally contracted in a short, straight beak, ventrally convex, dorsally openly sulcate, the valves thin, strigose, with black trichomes, becoming papery, ochre with age, reticulate; seeds not seen. Distribution:— Endemic to Mexico ; recorded around Mexico City , State of Mexico and Morelos ( Fig. 16 ). Habitat:— In conifer forest, 2500–2700 m . Comments:— The areas around Mexico City , adjacent areas with the State of Mexico, and Morelos harbor at least 11 species of Astragalus , however only two of these have triquetrous stipitate pods, A. lyonnetii and A. micranthus var. micranthus . The later species can be distinguished by its larger racemes ( 10–16 cm long, rarely 3–8 cm ), more flowers per raceme (30–60), smaller petals (banner 4.9–7 mm , wings 6.1–7.9 mm , the keel 4.8–7 mm ) and shorter stipe ( 0.1–0.5 mm ). In higher mountains ( 3000 m or more in elevation), A. harshbergeri inhabits the same areas that A. lyonnetii , but are easily distinguished by the creeping beahivor and the much wider stipules, which are double the stem´s width. There is a asample collected at Michoacán identified a A. lyonnetii ( B. Farfán H. 186, IEB), however it does not have pods and the racemes have only two flowers; perhaps a misidentification. Specimens examined:—MEXICO CITY: VIII-1927 , Pedregal de San Angel , E. Lyonnet 176 ( NY , US ) ; 11 July 1984 , C. Nieto P., A. Colín PR.1 ( IBUG , MEXU ) . MORELOS: 11 July 1976 , Tres Cumbres , sobre la carr. Federal a Cuernavaca, A . Delgado S. 252 ( MEXU ) ; 5 June 1972 , Autopista, J . Vázquez 3639 ( MEXU ) ; 1 August 1987 , M. Diaz G. 11, E. Cedillo ( ENCB ) . STATE OF MEXICO: 3 September 1967 , D. E. Hernández s.n. ( MEXU ) ; 11 August 1978 , R. Vega A. 381 ( ENCB ) .