Astragalus hornii A. Gray var. minutiflorus M. E. Jones,

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

43. Astragalus hornii A. Gray var. minutiflorus M. E. Jones, Proc. Calif. Acad. Sci. II. 5: 677. 1895

Type:— MEXICO, Baja California, San Jorge , 17 March 1889, T. S. Brandeee s.n. (holotype: CAS0000952 digital image!; isotype: UC not seen) .

Astragalus bajaensis E. Sheld. , Minnesota Bot. Stud. 9: 169. 189.— Astragalus hornii var. bajaensis M. E. Jones, Rev. N. -Amer. Astragalus 104. 1923.— Phaca bajaensis (E. Sheld.) Rydb., N. Amer. Fl. 24: 358. 1929.

Astragalus miserandus Greene, Erythea 3: 76. 189.

Annual. Sometimes forming patches 5 m wide and 0.5 m high. Stems up to 60 cm long, hollow, with tan, *reddish or purple tones, minute strigose, the trichomes up to 0.5 mm long. Stipules 2.5–7 mm long, the lowest connate, the upper ones semi-clasping, or only a tiny narrow line around stem´s circumference, triangular, deltoid to lanceolate. Leaves 1.5–13 cm long, leaflets 18–33, 3–23 mm long, oblong, elliptic to obovate, distally notched, adaxially glabrate. Peduncles 2–15 cm long, ascendant, incurved or straight; the racemes 1–3.5 cm long, dense when young, somewhat lax with age, subglobose or oblong, flowers 8–20. Flowers white, whitish or cream, sometimes with lilac tones or rose; the calyx 3.8–6 × 2–2.9 mm, lax strigose, trichomes up to 1.1 mm long, white o white and black mixed, the tube campanulate, 2.2–4.4 mm long, the teeth 1.5–2.5 mm long, subulate to triangular; the banner 7.2–10.4 × 3.5–8 mm, recurved, spathulate, elliptic to rhombic, slightly obcordate apically; the wings 6.8–9.9 × 1.4–3.1 mm, the claw, 2.7–4.5 mm long, the blade 4.5–7 mm long, linear, oblong, to oblanceolate, obtuse or emarginate; the keel 5.7–8.4 × 1.9–2.8 mm, the claw 2.9–4.5 mm long, the blade 2.8–4.6 mm long, semi-circular or semi-obovate. Pods close together to each other around rachis and forming a dense oblong raceme head-like), the body 0.9–1.8 × 0.4–0.9 cm, spreading or somewhat ascending, sessile, ovoid to obovate, persistent for a time, not quickly caducous, inflated bladder-like, rounded basally, symmetric, very rarely gibous, distally contracted in a narrow beak, ventrally straight o almost so, very rarely arquate, dorsally gibous, the valves membranous, papery, ochre, minute strigose, trichomes 0.4–0.7 mm long, appressed or ascending, turning glabrate with age, softly reticulate, sometimes with light pink tones; ovules 10–17; seeds 1.4–2.3 mm long, brown with purple tones. * R. V. Moran 29432 (ENCB, MEXU, NY).

Distribution:— This variety is endemic of the the peninsula of Baja California, in both states, in Baja California at the western end of the Sierra San Pedro Martir, also, along the western coast, 30°19’– 30°42’N (Vicente Guerrero, Punta Gorda, 5–6 km to the NNW of Prof. Graciano Sánchez, between Campo Sarabia and La Salina, Venustiano Carranza and Nueva Odisea), apparently absent to the south, but appearing in the political limits of Baja California Sur, 27°52’ (lagoons and bays, Guerrero Negro), again absent and appearing on the coasts 26°03’N – 26°17’N, (adjacent to coasts in San Juanico and Buenaventura). Also, in California ( USA) ( Fig. 12 ).

Habitat:— Plains; sandy soils; cemented terraces; saline lagoons adjacent to coastal dunes; just behind coastal dunes; small drainages and flats; associated with riparian-halophytic vegetation; creosote bush scrub; associated with saltgrass, pickleweed, as well as mesquite, psamophilic vegetation; 0– 15 m.

Reported also in elevations of 1100 m NW San Pedro Mártir (I. L. Wiggins 9179, NY) .

Comments:— The saline areas where this species occurs are also inhabited by other Astragalus with purple, lavander, white, lilac or pink flowers and with sessile, inflated bladder-like, longer than 7 mm pods, such as A. harbisonii , A. insularis var. quentinus , A. magdalenae var. magdalenae and A. trichopodus var. lonchus . Astragalus insularis var. quentinus is easily recognized by its racemes with very few flower (3–9). The other three ones are almost identical among them. However, A. hornii var. minutiflorus can be recognized and differentiated from the other species by its stipules being connate and by the oblong to head-like racemes. Ecologically, A. hornii var. minutiflorus inhabit in hard coastal terraces and saline lagoons, adjacent but behind the coastal dunes.

Specimens examined:—BAJA CALIFORNIA: 5 July 1980, El Socorro, R. V. Moran 28968 ( NY, SD) ; 19 October 1980, north of Laguna Mormona , R. Moran 29432 ( CAS, ENCB, MEXU, NY, TEX-LL, US); 2 October 1938, Los Pozos, northwestern end of Sierra San Pedro Martir, I. L. Wiggins 9179 ( CAS, NY, US); I-1889, San Quentin Bay, E. Palmer 646 ( NY) ; 16 December 1953, Camino de Playa Colonia Guerrero , Harbison, Higgins s.n. ( CAS, SD) ; 10 May 1886, San Ramon, C. R. Orcutt 1324 ( NY, US). BAJA CALIFORNIA SUR: 13 February1973, La Bocana de San Gregorio , R. V. Moran 20095 ( NY, US); 3 July 2016, Pequeño drenaje en pisos a lo largo de la carretera al este de Adolfo López Mateos; al oeste de Ciudad Insurgentes y al este de Bahía Magdalena, J. Rebman 31152, R. Domínguez, J. F. Pio León ( SD) ; 13 February1973, La Bocana de San Gregorio, R. Moran 20095, J. L. Reveal ( SD) .

Figures

FIGURE 12. Map showing the distribution of Astragalus hintonii var. hintonii, A. hintonii var. cofrensis, A. hornii var. minutiflorus, A. humistratus var. humistratus, and A. humistratus var. sonorae in Mexico.