Astragalus orcuttianus S. Watson, Proc. Amer. Acad. Arts

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

63. Astragalus orcuttianus S. Watson, Proc. Amer. Acad. Arts 20: 361. 1885

Type:— MEXICO, Baja California, Sierra Juárez, Cantillas Canon ( Cañón del Tajo ), 2 August 1883, C. R. Orcutt 937 (holotype GH 00059424 digital image!; isotype: UC (not found (at CCH 1)).

Tium orcuttianum Rydb., N. Amer. Fl. 24(7): 397. 1929. — Astragalus orcuttianus S. Watson var. gregorianus M. E. Jones, Contrib. W. Bot. 10: 63. 1902.

Perennial. Stems up to 40 cm long, few to abundant from base, minute strigose, trichomes up yo 0.6 mm long, appressed, straight. Stipules 1–4 mm long, triangular slightly amplexicual or triangular and semi-amplexicual, embarcing almost half of the stem circumference, not connate. Leaves 3–18 cm long, leaflets 13–25, 2–15 mm long, obovate to suborbicular to truncate or retuse, frequently gradually decreasing in size towards the apex, the pairs separated by 2–3 times the width of each other, sometimes some leflets subopposite or completely alternate along rachis. Peduncles 2–13 cm long, ascendant, incurved; the racemes 3–10.5 cm long, flowers 6–12. Flowers rosepurple; the calyx 4.8–6 × 2.7–3.2 mm, strigose, trichomes white o white and black mixed, the tube 2.6–3.8 mm long, campanulate, the teeth 1.6–2.2 mm long, triangular to subulate, one pair usually shorter and wider than rest; the banner 9–12 × 6–9.3 mm, recurved, ovate to suborbicular, slight or strongly retuse; the wings 8.1–10.4 × 1.8–3.6 mm, the claw 2.7–3.7 mm long, the blade 5.8–8.2 mm long, obovate to oblong, incurved; the keel 7.7–8.6 × 2.5–3.1 mm, the claw 3–3.7 mm long, the blade 4.8–5.6 mm long, incurved, triangular. Pod stipitate (stipe 1–3 mm long), the body linear to narrowly-obovate, 1.2–2.3 × 0.3–0.35 cm, straight o incurved, ascendant, rarely sigmoid-shaped and ascendant, triquetrous, basally narrow, distally contracted in a narrow triangular beak, compressed laterally, ventrally carinate, dorsally wide and openly carinate, lateral faces slightly concave and obtuse, the valves finely fleshy, greenish, turning papery and ochre with age, lustrous, slightly reticulate, septum incomplete; seeds 1.8–2.3 mm long, mitten shape, brown to light-brown.

Distribution:— Endemic to Mexico, exclusively on the Peninsula of Baja California, isolated in a few localities. In Baja Calfornia, in Sierras Juárez and San Pedro Mártir, Valle de los Cirios (28°19’N – 113°28’W) and Sierra Libertad (28°46’N – 113°49’W). In Baja California Sur, on the western coast between Pabellón and Francisco Villa (25°48’N – 112’01’W) ( Fig. 20 ).

Habitat:— Slopes, mountainous areas; rocky soils; desert scrubland with cacti, mezquite and palms; 305–1100 m.

Comments:— Of the28species registered from this Peninsula,only four of them( A.acutirostris , A.francisquitensis , A. nuttallianus y A. orcuttianus ) have triquetrous pods. Astragalus francisquitensis is isolated in the Sierra La Laguna (Baja California Sur), A. nuttallianus , with sessile pods. Astragalus orcuttianus and A. acutirostris converge in some low areas of the Sierra San Pedro Mártir, but, can be distinguished based on some particular characteristics, A. acutirostris is an annual with shorter racemes (1–4.5 cm long), few flowers (1–6) per raceme, smaller calyx (2.6–4.1 mm), smaller petals (banner, 4.7–7 mm, wings, 4.3–6.2 mm, the keel, 4.3–5.8 mm), shorter stipes (0.4–0.8 mm) and longer pods (up to 30 mm).

Specimens examined:—BAJA CALIFORNIA: 22 May 1996, Valle Las Flores; 11.9 millas al S de Bahía de Los Ángeles y 1.9 millas al SO de la carretera principal; lado este de Sierra la Libertad , J. Rebman 3154, J. Dunn, M. Polak ( BCMEX, SD) ; 22 April 1951, Cañon de Cantillas , C. F. Harbison s.n. ( CAS, SD) ; 30 March 1985, Cañon Carrizo, east side of Sierra de Juarez , the next major canyon N of C. de Guadalupe. Vicinity of major southward bend in the canyon, a couple of miles above its mouth, T. Dallman 33, M. Guzy ( NY) ; 7 July 1889, Cantillas Canon, C. R. Orcutt s.n. ( NY) ; 23–27 March 1957, Lower half of Canyon Diablito east face of San Pedro Martir Mountains , V. Stombler 130 ( CAS) ; 9 May 1941, Between La Huerta and El Cajon , Sierra San Pedro Martir, I. L. Wiggins 9824 ( CAS, US) ; 2 May 1889, Lower California , San Enrique, T. S. Brandegee s.n. ( US) ; 19 March 1960, Sierra San Borja , desembocadura del cañón en El Terminal, R. Moran 7938 ( SD) ; 15 March 1995, Cañón el Cajón, al oeste del camino de tierra principal que proporciona acceso al Cañón de Guadalupe , J. Rebman, A. Salywon, R. P. Martínez, G. Reinhardt, W. Hodgson 8743 ( SD) ; 22 February1986, Boca del Cañon de Guadalupe , E. Jonsson, D. Clemons 1305 ( SD) ; 12 April 2002, Misión de Santa Maria , M. Salazar 646 ( SD) ; 22 April 2009, Sierra La Libertad: vecindad de Las Cuevas; en Arroyo La Soledad y las laderas bajas circundantes, J. Rebman 17180, S. Bullock ( SD) ; 30 March 1991, Sierra La Asamblea, heading in from El Crucero off Hwy 1, 13.5 mi N of Jtn with main rd to Bahia de Los Angeles , in cyn SE side of Cerro La Gobernadora , S. Boyd 5554 ( MEXU) .

Figures

FIGURE 20. Map showing the distribution of Astragalus orcuttianus, A. oxyphysopsis, A. oxyphysus, and A. oxyrhynchus in Mexico.