Astragalus guanajuatensis Rzed. & Calderón, Acta Botanica Mexicana, 2015

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

34. Astragalus guanajuatensis Rzed. & Calderón, Acta Botanica Mexicana 110: 2. 2015

Type:— MEXICO, Guanajuato, San Agustín, municipio de Victoria, sitios húmedos en el pastizal, 30 Juyl1998, S. Zamudio, E. Pérez y L. Hernández 10772 (holotype: IEB) .

Perennial. Stems up to 20 cm long, creeping, diffuse, strigose, trichomes 0.2–0.5 mm long. Stipules up to 5 mm long, triangular, ovate to lanceolate, clasping, not connate, embracing completely the stem´s circumference, green, appressed, scattered pubescent, erect. Leaves 1.3–4 cm long, leaflets 15–27, 3–7 mm long, elliptic, oblong, linearoblong to oblanceolate, obtuse or truncate, glabrate adaxially, pilose to densely pilose abaxially. Peduncles up to 6 cm long; the racemes 2–3 cm long, flowers 12–18. Flowers yellow-greenish, ascending when young, soon deflexed; the calyx 3 × 1.7–1.9 mm, strigose, the trichomes black, the tube 2–2.6 mm long, campanulate, the teeth 1.2–1.5 mm long, triangular; the banner 9–11.2 × 5–6.1 mm, obovate, retuse, recurved, cuneate basally; the wings 4.8–6 × 2–2.5 mm, the claw 2 mm long, the blade 3–4.2 mm long, oblong; the keel 7–8 × 2.2–2.8 mm, the claw 2.4–3.1 mm long, the blade 4.5–5 mm long, incurved. Pod 9–13 × 2.5 mm, sessile, pendulous, straight or almost so, triquetrous, lateral faces subrounded or compressed, oblong, basally rounded to obtuse, distally contracted in a straight cuspidate, triangular beak, the valves yellowish, strigose, stiff, reticulate; ovules 8; seeds 1.5–1.8 mm long, mitt-shaped, square to sub-squared, brown, opaque.

Distribution:— Endemic to Mexico. Restricted to Guanajuato, Cañada de Moreno-Xichú, Municipality, between San Agustín and Puerto de Palmas (Rzedowski y Calderón, 2015) ( Fig. 9 ).

Habitat:— Open areas in oak-pine forest and grassland in Sierra Gorda.

Comments:— Of the several species of Astragalus with triquetrous pods and simple pubescence that are found in Guanajuato and adjacent areas, only A. guanajuatenesis and A. strigulosus (white, white-yellowish flowers) do not have purple, blue or a red-lilac combination in the flowers. These species can be separated based on their pod morphology since, A. strigulosus is stipitate and little longer, 1.7–2 cm long.

Specimens examined:—GUANAJUATO. 30 July 1998, San Agustín, municipio de Victoria, S. Zamudio, E. Pérez y L. Hernández 10772 ( IEB) ; 15 July 2011, Puerto del Aire , km 28 carr. Cañada de Moreno-Xicho, Mpio. Vicrtoria, P. Carrillo-Reyes,E. Carranza 6355 ( IEB) ; 15 July 2011, 1 km al SO de Derramaderos sobre el camino San Agustin-Puerto de Palmas , Mpio. Victoria, P. Carrillo-Reyes,E. Carranza 6339 ( IEB) .

Figures

FIGURE 9. Map showing the distribution of Astragalus goldmanii, A. greggii, A. gruinus, and A. guanajuatensis in Mexico.