Astragalus brauntonii Parish var. lativexillum A. E. Estrada, Rebman, C. González & Villarreal, 2022

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

7. Astragalus brauntonii Parish var. lativexillum A. E. Estrada, Rebman, C. González & Villarreal , Phytotaxa 577(1): 1–13. 2022

Type:— MEXICO. Baja California, Municipio de Tijuana , 7 June 2022, C. González 106 (Holotype SD!; isotype MEXU!).

Perennial, herbaceous, caulescent, perennial with taproot. Stems several, hardened at base, straight, fistulated, striate, erect or ascending, up to 1.5 m tall, densely villose to tomentulose, the trichomes, 1–1.7 mm long, entangled, white. Stipules 2.8–3 mm long, subulate to linear, abruptly widened at base, amplexicaul, decurrent, dorsally pubescent, embracing up to one-half the circumference of the stem. Leaves 5–15 cm long, gradually decreasing in size from base to apex, leaflets 25–33 per leaf, 3–20 mm long, ovate, narrow elliptic to elliptic-obovate, acute to obtuse at apex, greenish to canescent, somewhat folded or flat, carinate adaxially by the midrib. Peduncles single or several at the top of the stems, closely spaced, 0.7–1.5 cm, always shorter than leaf, 2–9 cm long, straight to incurved, pubescent as stem, recemes 2–14 cm long in fruit, (23–)35–60 flowers. Flowers purple to pink-purple, dull, the calyx campanulate, 6.1–8.1 × 3–3.8 mm, the tube 3–4.1 mm long, the teeth 2.4–6 mm long, membranous or papyraceous, villous with white trichomes or with white, black and fuscous ones mixed, or only with ones in the tube and fuscous ones at the teeth; the banner 9–11.7 × 4.5–7.5 mm, subentire to retuse, obovate, the wings 7.2–10.2 × 2–3 mm, elliptic-obovate, the claw 3.2–4.6 mm long, the blade 5.5–6.6. mm long, slightly incurved, narrow oblong-oblanceolate, auriculate; the keel 6.3–8.5 × 2.2–2.5 mm, the claw 3.3–4.3 mm long, the blade 3.7–4.5 mm, semi-obovate, incurved, apex rounded, auriculate. Pod deflexed, 6.4–9 × 2.5–4 mm, caducous, sessile or upon a thinly gynophore 0.7 mm long or shorter, the body oblong to ovate-oblong, plumply, obtuse to cordate at base, apically acute in a incurved to subulate 1–1.5 mm long beak, openly triquetrous, ventrally keeled by the suture, the dorsal suture deeply grooved, the lateral faces widely rounded, the valves green, light-brown to stramineous, thinly fleshy, somewhat coriaceous to stiffly papery, villous to tomentose, perpendiculary reticulated below pubescence; septum 1–1.3 mm wide; seeds 1.2–2.2 mm long, brown to dark-brown, shallow wrinkled.

Distribution:— Only known from the type locality, at the south of the city of Tijuana, Baja California ( Fig. 3 ), coexisting with A. tijuanensis .

Habitat:— In disturbed and burned area, with arid shrublands as the main vegetation, inhabiting clayish coils, in hillsides, slopes and flats.

Comments:— Easily recognized by erect habit and congested infrutescences with oblong to ovate-oblong and less than 1 cm long fruits.

Specimens examined:— BAJA CALIFRONIA: 7 June 2022, Mpio. Tijuana, C. González 106 (Holotype MEXU!; isotype SD!) .

Figures

FIGURE 3. Map showing the distribution of Astragalus arizonicus, A. brauntonii var. lativexillum, A. brazoensis, A. carminis, A. cenorrhynchus, and A. circumdatus in Mexico.