Name
Vachellia californica (Brandegee) Seigler & Ebinger, Phytologia 87: 146. 2005.syn. Acacia californica Brandegee, Proc. Calif. Acad. Sci. II. 3: 221. 1892.
Synonymy and types
Basionym: Acacia californica Brandegee, Proc. Calif. Acad. Sci. II. 3: 221. 1892. Acacia pringlei Rose subsp. californica (Brandegee) Lee, Seigler & Ebinger, Syst. Bot. 14: 99. 1989. Acaciopsis californica (Brandegee) Britton & Rose, N. Amer. Fl. 23: 96. 1928. - TYPE: MEXICO. BAJA CALIFORNIA SUR: La Palma, 31 Mar 1892, T. S. Brandegee s.n. [lectotype, designated by Lee et al. (1989): UC].
Acacia sonorensis Rose, Contr. U. S. Nat. Herb. 8:31. 1903. Acaciopsis sonorensis (Rose) Britton & Rose, N. Amer. Fl. 23: 95. 1928. - TYPE: MEXICO. SONORA: near Guaymas, 5-11 Jun 1897, J. N. Rose 1247 (holotype: US).
Formal description
Tree to 8 (12) m tall. Bark dark gray to brown, shallowly furrowed. Twigs dark purplish brown to dark gray, slightly flexuous, densely pubescent. Short shoots commonly present above the stipular spines, to 8 mm long, covered with acuminate stipules and old leaf bases. Leaves alternate, also commonly clustered on the short shoots, 4-10 mm long. Stipular spines light to dark purplish brown, usually becoming light gray with age, symmetrical, terete, straight, thin, to 35 (50) x 1.5 (3.0) mm near the base, lightly pubescent throughout. Petiole adaxially grooved, 4-10 mm long, densely pubescent; petiolar gland solitary, mostly located medially on the petiole, sessile, circular to elliptic, 0.4-1.8 mm long, apex depressed, glabrous to puberulent, sometimes absent. Rachis absent. Pinnae 1 pair per leaf, 15-35 mm long. Petiolules 3-18 mm long. Leaflets 2 to 3 pairs per pinna, subopposite to alternate, 5-18 mm between leaflets, ovate to obovate, terminal leaflet 11-25 x 6-18 mm, the lateral leaflets mostly smaller, densely pubescent on both surfaces, lateral veins obvious, 2 to 4 vein from the base, base oblique, margins densely ciliate, apex obtuse and usually mucronate. Inflorescence a loosely flowered elongated spike, 30-130 mm long, solitary or in clusters of 2 to 8 on the short shoots. Peduncles 0-6 x 0.6-0.9 mm, densely puberulent. Involucre usually 4-lobed, at the base of the peduncle, persistent. Floral bracts spatulate, 0.7-1.2 mm long, puberulent, deciduous. Flowers sessile, white to cream-colored; calyx 4-lobed, 0.7-1.4 mm long, glabrous and striated; corolla 4-lobed, 1.5-2.0 mm long, glabrous or nearly so; stamen filaments 2.5-4.0 mm long puberulent to glabrous, distince; ovary glabrous, on a stipe to 0.4 mm long. Legumes dark reddish brown, straight to slightly curved, flattened, sometimes slightly constricted between the seeds, linear, 60-200 x 5-8 mm, coriaceous, reticulately striate, glabrous, eglandular, dehiscent; a chartaceous pericarpic strip lining each valve; stipe to 12 mm long; apex acuminate and sometimes beaked. Seeds uniseriate, no pulp, dark gray to dark brown, oblong, strongly flattened, 6.3-10.0 x 3.5-4.5 mm, smooth; pleurogram oblong to U-shaped, 1.1-2.0 mm across. Flowers in March to July. Chromosome number: Not determined.
Distribution
From Baja California Sur to Sinaloa and Sonora.
Additional info
The species Vachellia pringlei and V. californica, though disjunct, are closely related and specimens are sometimes difficult to place. The species are usually easy to distinguish, however, by the presence of the dense pubescence on the smaller leaflets of V. californica. In addition, petioles are consistently very short in V. californica (less than 10 mm), the leaflet margins are strongly ciliate, and most parts of the plant are densely pubescent. The species are also similar in that a few specimens of V. californica tested positive for cyanide production if emulsin was used in the test (Lee et al. 1989).
Vachellia californica specimens from Baja California Sur differ in some respects from the material in Sonora and Sinaloa. Though possibly the result of the small number of specimens available for study, the calyx and floral bracts of these two groups of specimens differ slightly in size. In specimens from Baja California the calyx is 1.2-1.4 mm long, and the floral bracts are 1.0-1.2 mm long; Sinaloa and Sonora specimens have a smaller calyx (0.7-0.9 mm) and floral bracts (0.7-1.0 mm). They are similar in all other characteristics.
Flowering time
March-July.
Representative specimens
MEXICO:
Baja California Sur:
- La Paz and south, Santiago, 1 Apr 1936, L.H.Bailey 197 (F);
- Miraflores, 24 Mar 1892, T.S.Brandegee s.n. (F);
- Miraflores, 20 Mar 1939, H.S.Gentry 4357 (MO, UC);
- 4 miles S of La Rivera, alt. 150 ft., 19 Apr 1948, R.E.K.Peters 197 (UC);
- Arroyo de las Animas, Jan-Mar 1901, C.A.Purpus 273 (MO, NY, UC, US);
- 2 km S Santiago, 15 May 1980, M.J.Warnock 2077 (TEX);
Sinaloa:
- Sonora-Sinaloa boundary below Agiabampo, 17 Apr 1945, H.S.Gentry 7327 (F, GH, PH, NY, UC, US);
Sonora:
- 4 km N of Miraflores on hwy. 1, 19 Jun 1981, D.S.Seigler & P.M.Richardson 11778 (ILL);
- 9 km S of La Ribera, 20 Jun 1981, D.S.Seigler & P.M.Richardson 11783 (ILL);
- 5.9 miles NW of Soyopa, alt. 305 m, 29 Apr 1971, A.M.Carter, J.R.Hastings & R.M.Turner 71-83b (UC);
- 3.2 miles S of Soyopa, alt. 270 m, 29 Apr 1971, A.M.Carter, J.R.Hastings & R.M.Turner 71-85 (UC);
- 15 miles S of Bacanora along road to Tónichi, 16 May 1957, H.S.Gentry 16625 (US);
- 2 miles N of San Carlos Bay, 4 Jun 1962, P.C.Hutchinson 2454 (NY, TEX, UC, US);
- San Pedro Bay, 7 Jul 1921, I.M.Johnston 4333 (A, NY, UC, US);
- San Carlos Bay, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11707 (ILL);
- San Carlos Bay, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11708 (ILL);
- 2 km NW of Bahía San Carlos, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11711 (ILL);
- 2 km NW of Bahía San Carlos, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11712 (ILL);
- W of Bahía San Carlos, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11713 (ILL);
- 18 km N of the jct. of Hermosillo-Guaymas road, NW of Guaymas, 15 Jun 1981, D.S.Seigler & P.M.Richardson 11716 (ILL).