Astragalus insularis Kellogg, Bull. Calif. Acad. Sci.

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

48. Astragalus insularis Kellogg, Bull. Calif. Acad. Sci. 1: 6: 1884

Annual or biennal. Stems 1-few, up to 62 cm long, suberect, decumbent to prostrate, strigose, the trichomes up to 0.7 mm long, straight or appressed. Stipules 1–5 mm long, semi-clasping, triangular to deltoid, not connate. Leaves 2–13 cm long; leaflets 7–21, 3–19 mm long, lanceolate, oblong to elliptic, acute, obtuse or retuse, sometimes arched back, especially evident when folded, equally pubescent on both faces, subglabrate or glabrate. Peduncles 0.8–7 cm long, incurved, ascendant; the racemes 0.5–6 cm long, flowers 3–9, horizontal to pendulous. Flowers purple-reddish, darkpurple, magenta, blue-violet, blue, sometimes turning violet when dry; the calyx 3.1–4.6 × 1.8–2.3 mm, strigose, the trichomes white and black mixed, the tube 1.6–2.9 mm long, campanulate to sub-turbinate, with purple tones; the teeth 1.3–3 mm long, subulate, the ventral pair the longer; the banner 5.5–7.4 × 3.9–5.3 mm, recurved, distally notched; the wings 5–6.5 × 1.1–2.2 mm, the claw 1.6–2.2 mm long, the blade 3.5–4.7 mm long, oblanceolate to obovate, slightly incurved; the keel 4.8–6 × 1.6–2.1 mm, the claw 1.8–2.4 mm long, the blade 3–3.7 mm long, semi-obovate. Pod 0.9–2.4 × 0.5–1.5 cm, spreading to deflexed, sessile o diminutely elevated 0.1 mm above receptacle, ovoid to elliptic, sub-symetric, rarely lanceolate-elliptic or subglobose, inflated bladder-like, scarcely or strongly beaked, beak 2–7 mm long, the valves tan to pale-ochre or sometimes with purple tones, strigose, semi-diaphanous, somewhat lustrous, softly reticulate, septum absent; ovules 12–14; seeds 2.3–3.8 mm long, mitten shape, brown ochre or rose-brown.

Comments:— Astragalus insularis physognomically resembles to A. aridus and A. comonduensis , however A. aridus and A. comonduensis have ascending pod with 3–9 ovules.

The three infraspecific categories are recognized based on the shape of the pod and the shape and pubescence of the leaflets.

1. Pod sub-symetric, ovoid to subglobose, the beak up to 2.5 mm long, ventral suture equally convex than dorsally one; Baja California (Vicente Guerrero y San Quintín (30°39’ N – 115°32’ W), through El Rosario, to Rosario de Abajo de San Carlos , Santa Catarina and Canoas (29°28’ N – 115°11’ W) ...................................................................................................................................... var. quentinus

- Pod obliquely ovoid, the beak 2.5–7 mm long, ventral suture prominent, less convex than than dorsally one.................................2

2. Stems up to 30 cm long; leaflets acute and mucronate, adaxially glabrate, but few scattered trichomes all over the surface or along midvein abaxially or sometimes densely pubescent abaxially in individuals of Cedros Island; close to the coast (29°17’N – 114°49’W), also in the continental mass, through Mina Columbia, Punta Prieta , San Juan, to San Luis (28°20’N – 113°20´W), Cedros and San Lorenzo Islands, in west coasts of Baja California Sur, in close proximity to Puerto Nuevo (27°28’N – 114°30’W), through San Cristóbal, El Dátil, El Batequi, La Ballena, to San Juanico and Cedros Island (26°15’N. 112°34’W)............................ ........................................................................................................................................................................................ var. insularis

- Stems up to 55 cm long; leaflets obtuse or retuse, pubescent in both faces, sometimes adaxially glabrescent; northwest Sonora (San Luis Rio Colorado, Desierto de Altar and areas of El Pinacate, at south along the coast, from Puerto Peñasco, through Álvaro Obregón, Puerto Lobos, Puerto Libertad, Tordilla, Cabo Tepoca to Bahía Kino and San Clemente; south end of California Norte, La Guarda Island (29°21’28’’ N – 114°11’5.4’’ W), adjacent to San Lorenzo Island , close to Misión San Borja (28°44’36’’ N – 113°45’27.7’’ W), adjacent to Bahía San Felipe (31°04’33’’ N –114°51’00’’) and Misión Calamajué (29°25’27.8’’N – 114°11’42’’W ............................ ...................................................................................................................................................................................... var. harwoodii