Name
Vachellia bravoensis (Isely) Seigler & Ebinger, Phytologia 87: 146. 2005.syn. Acacia schaffneri (S. Watson) F. J. Hermann var. bravoensis Isely, Sida 3: 383. 1969.
Synonymy and types
Basionym: Acacia schaffneri (S. Watson) F. J. Herm. var. bravoensis Isely, Sida 3: 383. 1969. - TYPE: UNITED STATES. TEXAS: San Patricio Co., 7 miles S of Taft in clay loam soil, 29 Mar 1950, F. B. Jones 100 (holotype: SMU).
Formal description
Shrub or small tree to 4 (6) m tall. Bark grayish brown, shallowly furrowed. Twigs dark purplish brown to dark brown, slightly flexuous, glabrous to very lightly pubescent with erect hairs. Short shoots commonly present above the stipular spines, to 5 mm long, covered with acuminate stipules and old leaf bases. Leaves alternate, commonly clustered on the short shoots, 5-20 mm long. Stipular spines light to dark brown, usually becoming light gray with age, symmetrical, terete, straight, thin to stout, to 15(30) x 1.5 mm near the base, usually pubescent at least near the base. Petiole adaxially grooved, 2-8 mm long, usually densely pubescent with erect to ascending hairs; petiolar gland solitary, located at or just below the lower pinna pair, sessile, circular, 0.2-1.1 mm across, doughnut-shaped, glabrous. Rachis adaxially grooved, 0-18 mm long, pubescent, usually a sessile, circular gland 0.1-0.3 mm across, between the terminal and occasionally the other pinna pairs. Pinnae 1 to 3(4) per leaf, 7-28 mm long, 2-8 mm between pinna pairs. Petiolules 0.4-1.0 mm long. Leaflets 10 to 24 pairs per pinna, opposite, 0.5-1.1 mm between leaflets, oblong, 2.0-4.2(5.0) x 0.6-1.1 mm, glabrous, lateral veins sometimes obvious, only one vein from the base, base oblique, margins ciliate, apex broadly acute to obtuse. Inflorescence a densely flowered globose head, 8-11 mm across, solitary or in clusters of 2 to 5 on the short shoots. Peduncles 7-24 x 0.3-0.9 mm, densely pubescent, and small, red, deciduous glands also present. Involucre 4- to 5- lobed, located at the base of the globose head, lightly pubescent, persistent. Floral bracts spatulate, 0.8-1.3 mm long, puberulent, deciduous. Flowers sessile, yellow; calyx 5-lobed, 0.8-1.6 mm long, the lobes glabrous to puberulent; corolla 5-lobed, 2-3 mm long, the lobes glabrous to puberulent; stamen filaments 3.2-4.2 mm long; distinct ovary glabrous to densely pubescent, on a stipe to 0.2 mm long. Legumes dark brown to black, straight to slightly curved, nearly terete, usually constricted between the seeds, linear, 70-160 x 6-9 mm, coriaceous, recticulately striate, densely pubescent with erect hairs, glandular with minute, red, deciduous glands, indehiscent; stipe to 10 mm long; apex acute to obtuse. Seeds uniseriate, no pulp, light to dark brown, ovoid, slightly flattened, 6.0-9.1 x 5.0-6.5 mm, smooth; pleurogram oval, 3.1-5.0 mm across. Flowers in February to April. Chromosome number: 2n = 26 (Turner and Fearing 1960)
Distribution
Mostly disturbed sites between sea level and 1500 m elevation from southeastern Texas to Tamaulipas, Nuevo León, eastern Coahuila and northern San Luis Potosí, Mexico.
Additional info
Vachellia bravoensis is separated from V. schaffneri by the characteristics mentioned in the key, as well as the appearance of flowers before the leaves, smaller overall size, glabrous to only lightly pubescent twigs, and mostly glabrous petiolar glands. Though the number of pinna pairs found on V. bravoensis leaves is usually 3 or fewer, occasionally primary leaves have 4 pinna pairs. By far, however, the majority of the leaves have only 3 pinna pairs, whereas in V. schaffneri, the primary leaves mostly have 4 pairs of pinnae, with 5-6 common, and 7 rarely encountered. Also, the more northerly distribution of V. bravoensis, being extremely common in southern Texas and northeastern Mexico, helps to separate the two species. Though the two species are sympatric in a limited area of northeastern Mexico, only a few specimens were encountered that could not be assigned easily to a particular species; these were sterile individuals. Like V. schaffneri, all specimens of this variety tested were strongly cyanogenic.
Isely (1969) resolved the status of this taxon when he described it as a variety of Vachellia schaffneri. Turner (1959), as well as many others, placed this material with V. tortuosa as the fruit of these two taxa are similar, being constricted around the seeds, relatively long and narrow, and pubescent. Vachellia bravoensis, however, is easily separated from V. tortuosa by the presence of a circular petiolar gland located between to just below the first pinna pair, the fewer pinna pairs (1-3 vs. 4-6), the obscure lenticels, and the straight twigs.
Britton and Shafer (1908) first described this taxon as Acacia subtortuosa, recognizing that it is distinct from V. tortuosa, and citing its occurrence in Texas and adjacent Mexico. Though clearly describing V. bravoensis, the specimens cited (Palmer 11 and 510, from near Durango, Mexico) are clearly V. schaffneri.
Flowering time
February-April.
Representative specimens
UNITED STATES:
Arizona:
Pinal Co.:
- Boyce Thompson Southwestern Arboretum, 50 mi. E of Phoenix, alt. 777 m, 31 Jul 1992, J.Ricketson 4706 (MO);
California:
San Diego Co.:
- cultivated in San Diego, Oct 1949, C.R.Tower. s.n. (CDA);
Texas:
Atascosa Co.:
- roadside of farm road 140, 9 miles S of Jourdantown, 18 May 1980, S.G.Saupe & J.Koebrich 186 (ILL);
- 6 miles S of Jourdantown on hwy. 16, 20 May 1983 D.Seigler, J.Kramer & E.Carreira 11931 (ILL);
- S of Jourdantown, 29 Jun 1986, D.S.Seigler & B.Maslin 12670 (ILL);
- 9 miles S of Jourdantown, 15 Sep 1979, D.S.Seigler & D.A.Young 11382 (ILL);
Bee Co.:
- 4 miles SW of Skidmore, 28 Mar 1948, V.L.Cory 54134 (LL);
- S of Beeville, 17 Mar 1946, R.L.Crockett 1766 (LL);
Bexar Co.:
- 5 miles S of the bypass on S side of San Antonio, 22 May 1976, D.S.Seigler, S.G.Saupe & H.Welt 10054 (ILL);
- San Antonio, 1897, E.H.Wilkinson 55 (MO);
- 20 miles S of San Antonio, 20 May 1921, E.D.Schulz 481 (US);
Blanco Co.:
- 1 km E of LBJ State Park, hwy. 290, 14 Apr 1983, L.A.Johnston, M.C.Johnston & J.Henry 12756 (TEX);
Cameron Co.:
- Barreda, 7 Mar 1939, R.Runyon 2052 (F);
- Laguna Alascosa National Wildlife Refuge, 27 Apr 1961, R.J.Fleetwood 3678 (TEX);
Dimmit Co.:
- 3 miles S of Catarina, 1986, R.O.Albert s.n. (TEX);
- 11 miles W of Carizo Springs, 31 Mar 1959, M.C.Johnston 3840 (TEX);
Duval Co:
- 4 miles E of Bruni, 18 Mar 1963, D.C.Garcia 42 (LL);
Hidalgo Co.:
- N of San Juan, 6 Mar 1934, M.C.Ferguson & A.M.Ottley 4239 (UC);
- Santa Ann National Wildlife Refuge, 15 Feb 1960, R.J.Fleetwood 3183 (TEX);
- 13 miles N of Mission, 15 Nov 1943, C.L.Lundell & A.,A.Lundell 12685 (US);
Jim Hogg Co.:
- 2 miles N of Premont, 10 Mar 1963, J.H.Ramirez, N.Lopez & W.L.McCart 8771 (LL);
Jim Wells Co.:
- 5 miles S of Alice on hwy. 281, 25 Nov 1985, C.Coffey 1552 (WIS);
- gravel pit 9 miles N of Alice on U.S. route 281, 6 Jun 1991, D.Seigler, J.Ebinger, H.Clarke & K.Readel 13772 (EIU, ILL);
Karnes Co.:
- 4.8 miles SE of Falls City, 4 Jul 1952, J.C.Johnson 917 (TEX);
Kinney Co.:
- 5 miles E of Spofford, 9 Jun 1955, B.L.Turner 3875 (TEX);
Kleberg Co.:
- Riviera Beach, 9 Mar 1963, F.G.Gongora, J.D.Garcia & W.L.McCart 8797 (TEX);
- King Ranch, 16 Apr 1954, M.C.Johnston 54487 (TEX);
La Salle Co.:
- 8 miles N of Encinal, 2 Mar 1962, A.Alvarez, P.Guajardo, J.Salazar & W.L.McCart 7611 (LL);
- Mesquito flat 3 mi. S of Dilley, 26 Feb 1944, J.T.Painter & F.A.Barkley 14317 (MO);
Maverick Co.:
- 14 miles E of jct U.S. 277 & U.S. 57 near Eagle Pass, 21 May 1983, D.Seigler, J.Kramer & E.Carreira 11967 (ILL);
- 5 miles N of jct of interstate hwys. 57 and 277, 21 May 1976, D.S.Seigler, S.G.Saupe & H.Welt 9990 (ILL);
- 2 miles N of jct. of hwy. 57 & 277, 16 Sep 1979, D.S.Seigler & D.A.Young 11406 (ILL);
McMullen Co.:
- thorn-scrub pasture, 1 mile N of Texas route 791, 11 May 1991, D.Seigler, J.Ebinger, H.Clarke & K.Readel 13270 (EIU, ILL);
Medina Co.:
- 1 mile S of Devine on hwy. 81, 17 Mar 1963, A.Sanchez 65 (TEX);
Nueces Co.:
- Corpus Christi, 13 May 1900, V.Bailey 262 (US);
- Corpus Christi, 5-12 Mar 1894, A.A.Heller 1388 (ILL);
- Corpus Christi, 2 Jun 1894, A.A.Heller 1383 (F, US);
Refugio Co.:
- 3 miles SE of Austwell, 6 Apr 1959, D.S.Correll 20847 (LL);
San Patricio Co.:
- 1 mi. SE of St Paul, 5 Mar 1977, S.R.Hill 4652 (MO);
Starr Co.:
- 3.5 miles S of La Gloria, 8 Feb 1969, D.S.Correll 36751 (LL);
Uvalde Co.:
- along hwy. 90, W of Uvalde and 2.8 mi. E of the Nueces River, 18 Mar 1983, L.C.Barnett & L.J.Dorr 33 (MO, TEX);
- outskirts of Sabinal, 15 Mar 1934, M.C.Ferguson & A.M.Ottley 4360 (UC);
- along FM 1049 S of Knippa, 29 Mar 1983, T.M.Keeney 2434 (ILL);
- 10 miles S of Uvalde, 15 Jun 1945, C.H.Mueller 8081 (LL);
Victoria Co.:
- Victoria, 10 Apr 1900, H.Eggert s.n. (MO);
Wharton Co.:
- 3 miles SW of Louise, 17 Apr 1964, D.S.Correll 29342 (LL);
Webb Co.:
- Catarina, 1 Jun 1986, R.O.Albert s.n. (TEX);
- on Río Grande Plains, 30 miles N of Laredo on U.S. hwy. 83, 17 Apr 1973, T.Johnston 4 (WIS) 7 miles N of jct of U.S. 83 & I-35 on U.S. 83, 21 May 1983, D.Seigler, J.Kramer & E.Carreira 11958 (ILL);
- 30 miles S of Catarina on U.S. 83, 22 May 1976, D.S.Seigler, S.G.Saupe & H.Welt 10006 (ILL);
Zavala Co.:
- 11 miles N of Crystal City, 27 Mar 1964, J.Moore, A.Carrasco, H.G.Gongora &. W.L.McCart 8988 (LL).
MEXICO:
Coahuila:
- Hermanas, 20 Apr 1039, E.G.Marsh 1604 (TEX);
- Coahuila and vicinity, 1898, E.Palmer 33 (F);
- 22 miles W of Melchor Múzquiz, 1 Jun 1983, D.Seigler, J.Kramer & E.Carreira 12059 (ILL);
- Cañon de Aparicio, alt. 1300 m, 7 Jun 1991, J.A.Villarreal & R.Vásquez 6029 (TEX);
Hidalgo:
- Mission, Lomita Alta, Jun 1937, C.E.R.Cameron 27 (F);
- McCook, 30 Oct 1939, E.G.Marsh, Jr. 56 (F);
Nuevo León:
- roadside of route 60 between Linares and Galeana, above "Linares Canyon", alt. 1500-2000 m, 24 Dec 1987, E.M.Chittenden & T.Atkins 87 (MO);
- 5.1 km S of Allende, on hwy. 85, 1 Jul 1986, D.S.Seigler & B.Maslin 12675 (ILL);
- Open thorn -scrub just E of Cadereyta on Mexico route 54, 16 May 1991, D.Seigler, J.Ebinger, H.Clarke & K.Readel 13435 (EIU);
- Open thorn -scrub in pasture, 30 mile N of China on Mexico route 40, 5 Jun 1991, D.Seigler, J.Ebinger, H.Clarke & K.Readel 13757 (EIU, ILL);
San Luis Potosí:
- 22 miles S of Matehuala, alt. 4800 ft., 11 Feb 1960, J.Crutchfield & M.C.Johnston 5091 (TEX);
- Edge of Mexico 57, 37 km N of San Luis Potosí, 16 Dec 1990, D.Seigler, J.Ebinger, H.Clarke & K.Readel 13118 (ILL);
- 18 miles NE of San Luis Potosí, on hwy. 57-80, 20 May 1980, D.S.Seigler, P.M.Richardson & S.Thompson 11518 (ILL);
Tamaulipas:
- along hwy. Mex. 101, 8 km NE of Jiménez, 20 Jun 1980, M.Nee & B.F.Hansen 18311 (F, GH);
- SE outskirts of Ciudad Victoria, alt. 400 m, 22 Oct 1981, M.Nee 22217 (F);
- El Capason Ranch, 12-23 Jul, R.Runyon 411 (US);
- 25 miles SE of Matamoros, 11 Mar 1925, R.Runyon 3560 (TEX).