Astragalus gruinus Barneby, Mem. N. Y. Bot. Gard.

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

33. Astragalus gruinus Barneby, Mem. N. Y. Bot. Gard. 13: 848. 1964

Type:— MEXICO, Baja California, Vallecitos, Sierra San Pedro Martir , 21 September 1930, Wiggins & Demarée 4969 NY00005797!; isotype: CAS 0000954 digital image!, GH00059414 digital image!, LA00000099 digital image!).

Perennial. Stems 30–65 cm long, hard, commonly branched at base, erect to ascending, sometimes decumbent, spreading, tiny strigose, the trichomes up to 0.6 mm long, appressed, straight. Stipules 2–5 mm long, clasping o semiclasping, not connate, papery with age, triangular. Leaves 6–13 cm long, leaflets 9–25, 5–16 mm long, lanceolate, oblong to elliptic, acute, obtuse or retuse distally, glabrate or pilose adaxially. Peduncles 5–9 cm long, curved and ascending; the racemes 2–5 cm long, flowers 10–18. Flowers purple, lavender, cream but with considerable blue and lavender tints on wings and banner, sometimes the banner lavender and the wing and keel white or the flowers blueviolet; the calyx 5.3–6.9 × 2.2–3.2 mm, densely strigose, the trichomes black and few white mixed, sometimes only white trichomes, the tube 3–4 mm long, the teeth 2.3–3 mm long, subulate; the banner 8.4–11 × 5.3–7 mm, recurved, rhombic to ovate, narrowed basally, wide retuse apically; the wings 8.2–10.6 × 2–2.5 mm, the claw 3.2–3.8 mm long, the blade 5.5–7.2 mm long, oblong, half lunate; the keel 7–8.6 × 2–2.7 mm, the claw 3.3–3.8 mm long, the blade 4–5.3 mm long, triangular, strongly incurved. Pod 1.8–2.8 × 1–1.5 cm, sessile, subglobose to ovoid, inflated bladder-like, rounded basally, apically contracted and ending in a 2–2.5 mm long beak, slightly sulcate ventrally, the valves tiny strigose pale green or with purple spots, papery, sublustrous, softly reticulated, septum absent; ovules 24–26; seeds 2.6–2.9 mm long, mitt-shaped, the notch shallow to deep, brown, opaque.

Distribution:— Endemic to Mexico. Restricted to the Sierra San Pedro Mártir (Yerbabuena, Vallecitos, La Encantada, near the Observatory), and the Sierra La Asamblea and Rancho San Luis) in Baja California ( Fig. 9 ).

Habitat:— Rocky slopes, gravelly, sandy and granitic soils; granite boulders; steep walled canyons; shaded crevices and bases of outcropings; dry sands in canyon floor; dry sandy soils of meadow; hillsides and outwash slopes, grasslands, oak-forest, pine - oak forest; pine - manzanita; pine - fir; pine forest, associations with pine - manzanita; 1750–3213 m.

Comments:— Astragalus palmeri and A. gruinus are sympatric and converge at the same altitudes in both, oak and conifer forests of the Sierra San Pedro Mártir, although A. palmeri inhabits mostly in lower elevation plant communities. Both species share several characters in common such as purple flowers, (sometimes pink-purple or shiny-pink in A. palmeri ), sessile and inflated pods, however, A. palmeri has commonly longer racemes, reaching up to 21 cm long, and the pedicel is persistently attached to the plant when fruit ripens and fall, while in A. gruinus the pedicel (together with calyx and fruit) is detached from the plant falling as a unit. Astragalus douglasii also has sessile and inflated pods, but differs significantly from the two aforementioned species by its white, yellow, or ochroleucous flowers.

Specimens examined:—BAJA CALIFORNIA: 28 June 1996, Sierra San Pedro Martir, Vallecitos area ; 1.7 miles north of turn to La Tasajera and 2.2 miles southeast of observatory road, J. Rebman 3254 ( BCMEX, SD) ; 30 August 1963, Sierra San Pedro Mártir. La Corona , R. V. Moran 11268 ( MEXU, NY, SD) ; 2 June 1975, San Isidoro, R. V. Moran 22306 ( NY) ; 15 July 1905, Vallicitos, San Pedro Martir Mountains , E. A. Goldman 1224 ( NY) ; 8 May 1986, Sierra San Pedro Mártir : a few miles below entrance to Parque Nacional, R. F. Thorne 62007, T. S. Elias, P. Rojas ( NY) ; 18 August 1967, Sierra San Pedro Mártir. La Encantada , R. V. Moran 14309, R. F. Thorne ( NY, SD, TEX-LL) ; 21 September 1930, Vallecitos , Sierra San Pedro Mártir, I. L. Wiggins 4969, D. Demarée ( NY) ; 18 June 1985, Vallecitos: near road to Observatory and camp-ground, R. F. Thorne 60837, R. Dahlgren, S. Boyd and D. Charlton ( NY) ; 19 June 1985, Parque Nacional San Pedro Martir, observatory Mt: Near Observatory , R. F. Thorne 60900, R. Dahlgren, S. & D. Charlton ( MEXU, NY) ; 18 September 1983, Rocky slopes around observatory near E crest of Sierra San Pedro Mártir, R. F. Thorne 57269, K. Kubitzki, P. Paterson, C. Annable ( CAS, NY) ; 4 September 1961, Sierra San Pedro Mártir. Southeast side of La Encantada meadow, I. L. Wiggins 16620 ( CAS, NY) ; 18 June 1981, On shoulder of new road to Observatory 6.1 miles west of Vallecitos Meadow , Sierra San Pedro Mártir, I. L. Wiggins 21485 ( CAS, ENCB) ; 24 September 1930, High peaks above La Grulla , Sierra San Pedro Martir, I. L. Wiggins 5035 and D. Demaree ( CAS, MEXU, NY) ; 16 June 1954, 7 miles from canyon mouth, Canyon del Diablo to the north and west of Picacho del Diablo ( Cerro La Encantada ) eastern flank of Sierra San Pedro Martir, K. L. Chambers 608 ( CAS) ; 18 September 1930, Margins of Meadow at La Encantada , Sierra San Pedro Martir, I. L. Wiggins 4890, D. Demaree ( MEXU, NY, US) ; 5 September 1961, Sierra San Pedro Mártir. On trail from La Encantada to rim of range, I. L. Wiggins 16627 ( CAS, NY) ; 16 August 1967, Sierra San Pedro Mártir. Yerba Buena, R. Moran 14133, R. F. Thorne ( CAS, ENCB, NY) ; 22 August 1972, Sierra San Pedro Mártir Natl. Park. ca. ½ mi inside park entrance; ca. 21 mi E of Meling Ranch, B. Moulis 554, L. McGill ( NY) ; 12 August 1979, Near pond by Río Santo Domingo north of Villa Guerrero , R. Moran 27984 ( CAS, NY, SD) ; 14 September 1968, Sierra San Pedro Mártir. On north slope of Cerro “2828”, R. Moran 15625 ( MEXU, NY, US, SD) ; 18 May 1972, La Encantada Meadows, San Pedro Martir , E. McMillan s.n. ( CAS) ; 20 September 1968, At the NW end of the Sierra San Pedro Martir 8 miles north of Vallecitos , Municipio of Ensenada , D. E. Breddlove 16347 ( CAS) ; 16 June 1954, 7 miles from canyon mouth, Canyon del Diablo to the north and west of Picacho del Diablo ( Cerro La Encantada ) eastern flank of Sierra San Pedro Martir, K. L. Chambers 608 ( CAS) ; 18 June 1971, Steep mountain side about 1 km W of teh Observatory above Vallecitos Meadow, Sierra San Pedro Mártir, I. l. Wiggins 21478 ( CAS, ENCB) ; 18 June 1971, On shoulder of new road to Observatory 6.1 miles west of Vallecitos Meadow , Sierra San Pedro Mártir, I. L. Wiggins 21485 ( CAS, ENCB) ; 16 August 1967, Sierra San Pedro Martir , above Yerba Buena, R. Moran 14227, R. F. Thorne ( SD) ; 27 June 1998, J. Rebman 5378, A. Russell ( SD) ; 2 July 1982, Sierra San Pedro Martir , near summit of Cerro de la Cupula (=C.2828), at roadside, R. Moran 30982 ( SD) ; 18 October 1980, Río San Rafael, Los Zaguaritos , on damp sandy flood plain, R. Moran 29398 ( SD) ; 9 August 1969, Sierra San Pedro Martir , meadow at Vallecito, H. Witham 373, F. Hommersand ( SD) ; 16 June 1988, Sierra San Pedro Martir, ‘ Corral Meadow’ , 7.5 km NW (340°) of the observatory; mountainous region of granite boulder-covered slopes with a meadow & small stream, A. C. Sanders 7912, R. Minnich, E. Franco, M. Salazar ( SD) ; 2 July 1973, ierra San Pedro Martir, near summit of Cerro Botella Azul, in gravelly soil, R. Moran 21077 ( SD) ; 3 July 1990. Sierra San Pedro Martir, west slope of Cerro Venado Blanco, in sandy bottom, R. Moran 31041 ( SD) ; 25 August 1968, Sierra san Pedro Martir, valley in upper Arroyo Copal , on dry forest floor, R. Moran 15492 ( SD) ; 28 July 1970, Sierra San Pedro Martir, El Alto de Corona , R. Moran 17910 ( SD) ; 1 July 1998, Sierra San Pedro Martir, Bajio de las Viejas, J. Delgadillo, s.n. ( SD) ; 21 July 1988, Sierra San Pedro Martir, Oak Meadow area below entrance station ( Cieneguita de Soto ), S. Boyd 2834 ( MEXU, SD) ; 24 April 2004, Sierra La Asamblea: northeast of El Crucero (junction of Hwy. 1 & the road to Bahia de Los Angeles ), NNW of Rancho San Luis; along the trail between the ranch & the camp called “Datilillo”, J. Rebman 10019 ( SD) ; 30 September 2008, Sierra San Pedro Martir: southeast of Vallecitos and approximately 3 miles south of the Observatory ; up a canyon with an intermittent stream en route to Pedro’s Dome, J. Rebman 15984, M. A. Kessler, V. Marshall, M. Dykens ( SD) ; 12 July 2013, Sierra San Pedro Martir (turnout N side or road, SE of Observatory), S. Ratay 200 ( SD) ; 8 July 1997, Parque Nacionale Sierra San Pedro Martir, Vallicitos Meadow , extreme western margin, J. M. Porter 11484 ( SD) ; 16 July 1988, Sierra San Pedro Martir , ca. 1.5 km N of Cerro Observatorio, vicinity of Base Camp number 1, R. F. Thorne 63376, A. Liston, D. Nordin ( SD) ; 9 June 2016, Sierra de San Pedro Martir : upper northeastern end of Santa Rosa Meadow, J. Rebman 31725, S. Vanderplank, A. Harper ( SD) ; 18 June 1985, Parque Nacional San Pedro Mártir : ca. 3 miles below entrance to parquet, R. F. Thorne 60805 ( MEXU) ; 29 September 1970, Vallecitos, Parque Nacional , Ensenada, A. May Nah 3442 ( MEXU) ; 14 September 1968, Sierra San Pedro Martir, R. Moran 15625 ( MEXU) ; 16 July 1988, D. Charlton 2198 et al. ( ENCB) .

Figures

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