Vachellia gentlei (Standley) Seigler & Ebinger, Phytologia 87: 158. 2005.syn. Acacia gentlei Standley, Publ. Field Mus. Nat. Hist. Bot. Ser. 22: 77. 1940.
Synonymy and types
Basionym: Acacia gentlei Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 22: 77. 1940. - TYPE: BELIZE: P. Gentle 185 (holotype: F).
Tree to 20 m tall. Bark not seen. Twigs dark reddish brown, not flexuous, densely puberulent. Short shoots absent. Leaves alternate, 70-180 mm long. Stipular spines reddish to dark brown, most commonly black, mostly symmetrical, terete, suberect to recurved around the stem, stout and inflated, 35-80 x 3.5-6.0 mm near the base, usually lightly puberulent. Petiole adaxially grooved, 9-20 mm long, densely puberulent; petiolar glands 1(2), located near the base to the middle of the petiole, sessile, narrowly volcano-shaped and usually laterally compressed, base 2-3 mm long, apex nearly circular, 0.6-1.2 mm across, puberulent and lightly striate. Rachis adaxially grooved, 50-170 mm long, puberulent, a narrow, sessile, volcano shaped gland located along the rachis between the pinnae pairs. Pinnae 5 to 12 pairs per leaf, 55-90 mm long, 13-20 mm between pinna pairs. Petiolules 1-2 mm long. Leaflets 20 to 35 pairs per pinna, opposite, 1.7-2.4 mm between leaflets, linear, 7-14 x 1.8-3.1 mm, glabrous, lateral veins obvious, 3 to 5 veins from the base, base oblique, margins ciliate, apex obtuse to acute; beltian bodies 1-2 mm long. Inflorescence a densely flowered cylindrical spike nearly the same thickness throughout, 15-40 x 4-6 mm, commonly in racemes on fertile branchlets with usually one (2-4) spike in the axil of a reduced leaf. Peduncles 16-22 x 0.7-1.1 mm, puberulent. Involucre 4-lobed with 2 lobes longer, located near the middle of the peduncle, puberulent, persistent. Floral bracts peltate, 0.7-1.0 mm long, apex circular and usually puberulent, deciduous. Flowers sessile, yellowish; calyx 5-lobed, 0.5-0.8 mm long, puberulent; corolla 5-lobed, 1.3-1.8 mm long, twice as long as the calyx, puberulent; stamen filaments 1.6-2.6 mm long, distinct; ovary glabrous, subsessile. Legumes black to dark brown, straight to slightly curved, elliptical in cross section, not constricted between the seeds, linear, 160-300 x 9-14 mm, coriaceous, reticulately striate, glabrous, eglandular, dehiscent along both sutures; stipe 10-30 mm long; apex beaked 10-40 mm long. Seeds uniseriate, imbedded in a white to yellowish pulpy material, light brown, ovoid, slightly flattened, 7.0-9.5 x 3.8-5.5 mm, smooth; pleurogram oval to elliptic, 3.3-4.5 mm across. Flowers in January to May. Chromosome number: Not determined.
Rain forests, wet successional area where the vegetation is 15-20 years of age, wet disturbed sites, swamps, and river edge vegetation in the lowlands of Belize, northern Guatemala, and extreme southeastern Mexico (Seigler and Ebinger 1995).
Vachellia gentlei is a common species in wet sites at lower elevations in Belize, Guatemala, and extreme southeastern Mexico. It is distinguished easily from all other ant-acacias by the combination of its elongate inflorescence, laterally compressed, volcano-shaped glands scattered along the leaf rachis, very thin spines (usually less than 6 mm thick), and relatively large leaflets (7-14 mm long) with obvious secondary veins.
Unlike many of the wet forest ant-acacias, Vachellia gentlei is a common species in areas of human disturbance. It appears as a successional species after logging, and in many parts of its range is found along roadsides. Unlike most wet forest ant-acacias, it has relatively large Beltian bodies (1-2 mm long) on most of the leaflets. Like most of the other ant-acacias, it usually lacks cyanogenic glycosides in the leaflets. Of the specimens examined, only one, Lundell 16903, from Guatemala, was weakly cyanogenic.
- Chaa Creek, Cayo Dist., 30 Apr 1922, J.L.Brown & R.Cocon 27 (MO);
- Dist. Cayo, vicinity of Cuevas, S of Millionaria, alt. 1900 m, 29 May 1973, T.B.Croat 23546 (US);
- Toledo Dist., Maya Mts., alt. 100-200 m, 12 Mar 1987, G.Davidse & A.E.Brant 32402 (MO);
- Rio Frio Caves area near Augustine, 8 Jul 1972, J.D.Dwyer 10152 (MO);
- 28.5 miles NW of Belize, Northern hwy., Belize Dist., 24 May 1973, J.D.Dwyer 10729 (MO, US, WIS);
- 3-6 miles S of Belmopan, Cayo Dist., 30 May 1947, J.D.Dwyer 12544 (F, GH, MO);
- Southern Hwy., 14 miles N of Punta Gorda, San Antonio, alt. 300-500 ft., 11 Jun 1973, A.Gentry 8072 (MEX, MO, US);
- Maskall, Jan 1934, P.H.Gentle 1121 (F, GH, MICH, MO, NY, US);
- El Cayo Dist., near camp 6, 9 Mar 1938, P.H.Gentle 2311 (F, MO);
- near Condemn, Branch Pine Ridge, Toledo Dist., 27 Jan 1945, P.H.Gentle 5165 (F, MO);
- Toledo Dist., between Orange Point and Moho River, 9 Apr 1952, P.H.Gentle 7643 (MO);
- Hummingbird Hwy, Cayo Dist., 28 Apr 1956, P.H.Gentle 9078 (F, MICH, MO, NY);
- 7.3 miles NW of central X-road in Spanish Lookout settlement, Cayo Dist., 14 Apr 1970, R.R.Innes 271 (MO);
- 13.5 miles S Santa Elena on hwy from Ciudad Chetumal to Orange Walk, Corozal Prov., 30 Jun 1966, D.H.Janzen 575 (F, MO, US);
- near Gallon jug, alt. 400 ft., Mar-May 1958, D.A.Lancaster 31 (US);
- Little Cocquericot, Belize River, 27 Mar 1933, C.L.Lundell 4406 (F);
- El Cayo Dist., Valentin, Jun-Jul 1936, C.L.Lundell 6328 (NY);
- 75 miles NE from Bermudian Landing, W bank of Belize River, cattle pasture, 22 Mar 1992, V.Nickerson 62 (WIS);
- on Anderson Road, 0.5 miles S of Chiquibal Road, alt. 480 m, 31 Mar 1989, J.A.Northup 531 (WIS);
- Río Grand River, alt. 250 ft., 25 Mar 1933, W.A.Schipp 1142 (F, MO, UC);
- Boston, a 5 km al S de Corohead Creek, alt. 10 m, 4 Dec 1981, M.Sousa, T.P.Ramamoothy, G.Ibarra M., L.Rico & P.Basurto 12203 (MO);
- Caves Branch, Mountain Cow Hill, 25 Jul 1976, C.Whitefoord 1123 (MO);
- Cayo Dist., Chiquibal Road S of Guacamallo Bridge, 20 May 1981, C.Whitefoord 2871 (MO);
- Mountain Pine Ridge, Blancaneaux Lodge, 18 Aug 1970, J.R.Wiley 457 (MO).
- along Río Sebol between Sebol and Carrizal, N of Sebol, alt. 200-300 m, 18 Apr 1942, J.A.Steyermark 45762 (F);
- El Zapotillo, 1 km E El Estor (Lake Izabal), 16 May 1965, D.H.Janzen 657 (F, GH, MEX, MICH, MO, US);
- El Zapotillo, 1 km E El Estor (Lake Izabal), 18 May 1965, D.H.Janzen 659 (F, MO, US);
- El Zapotillo, 1 km E El Estor (Lake Izabal), 18 May 1965, D.H.Janzen 690 (F, MO, US);
- Finca El Zapotillo, N shore of Lake Izabal, 17 May 1966, G.C.Jones & L.Facey 3424 (F, LL, UC);
- 1-5 km from hwy. CA-9 on road to Mariscos, Lake Izabal, 26 Apr 1966, C.G.Jones, G.R.Proctor & L.Facey 3095 (F, LL);
- Río Dulce, 2-4 miles W of Livingston, alt. 1-3 m, 16 Apr 1940, J.A.Steyermark 39546 (F);
- Uaxactum, 18 Apr 1931, H.H.Bartlett 12578 (NY, TEX, UC, US);
- Uaxactum, 21 Apr 1931, H.H.Bartlett 12676 (UC, US);
- Dolores, km 82 on Machaquilla road, 17 May 1961, E.Contreras 2318 (F, MO);
- Santa Elena, on La Cueva de Jobitzinaj road, 12 Apr 1962, E.Contreras 3586 (F, MO);
- Tikal National Park, Tikal, in ramonal, Mar 1961, J.A.Ibarra 16 (LL);
- Fallaben-Yaxha road, Mar 1933, C.L.Lundell 2195 (F);
- La Libertad, 1 Apr 1933, C.L.Lundell 2379 (F);
- Chicbul, La Libertad, Apr 1933, C.L.Lundell 2611 (F);
- Chicbul, La Libertad, 7 Jun 1933, C.L.Lundell 3660 (F);
- Tikal, on top of temple in "H" group, 6 Mar 1961, C.L.Lundell 16903 (MO);
- Parque Nacional Tikal, 18 Mar 1970, R.T.Ortíz 786 (F, MO);
- Parque Nacional Tikal, 23 Apr 1970, R.T.Ortíz 999 (F, MO);
- Parque Nacional Tikal, 18 Mar 1970, R.T.Ortíz 1728 (F, US);
- Santa Elena, en el camino para Melchor, alt. 400 m, 10 Feb 1972, R.T. Ortíz 2261 (US);
- Laguna Petexbatum, alt. 50 m, 3 May 1942, J.A.Steyermark 46221 (F);
- San Luis, 20 Apr 1976, P.Ventur 197 (F);
- SE "Cerro Caubui", 14 May 1986, R.L.Walker 1390 (MO).
- Carretera a Tomás Garrido, 17 Mar 1999, M.Peña-Chocarro & J.Tun 478 (MO);
- km 10 camino N.C.P. Velasco Suárez-Nuevo Jalisco, alt. 500 m, 9 Mar 1977, J.I.Calzado 3111 (MO);
- a 20 km al SE de la desv. a San Javier-Frontera Echeverría, 12 Apr 1981, R.Durán, A.Chimal & J.Manuel s.n. (MO);
- a 3 km al S de Frontera Corozal, sobre el Río Usumacinta, alt. 120 m, E.Martínez S. 11433 (MEX, MO, NY);
- a 3 km al SE de Lacanjah Tzeltal camino Santa Domingo, 25 Jan 1986, E.Martínez S. 16795 (MO, WIS);
- a 15 km al NW de Boca Lacantum camino a Palenque, alt. 220 m, 10 Apr 1985, E.Martínez S. 11892 (MO);
- en Nvo. Guerrero a 100 km SE de Palenque camino a Boca Lacantum, alt. 350 m, 27 Jun 1986, E.Martínez S. 1907 (MO);
- a 2 km al N de Estero Franco, carretera Chetumal-La Unión, 24 Apr 1982, E.Cabrera & H. de Cabrera 2512 (MEX, MO);
- a 8 km al sur de Tres Garantias, sobre el camino a Tómas Gardido, 26 Apr 1982, E.Cabrera & H. de Cabrera 2520 (MO);
- a 8 km al N de la Unión, extreme S de Quintana Roo, 7 May 1982, M.Sousa, E.Cabrera, G.Davidse & A.Chater 12344 (MO);
- a 5 km al del Ingenio Álvaro Obregón, 10 Apr 1980, O.Téllez & E.Cabrera 1956 (MO);
- a 15 km al S de F. Carrillo Puerto, 6 May 1980, O.Téllez & E.Cabrera 2074 (MO);
- Carretera W-O por El Poblado de Apatzingán, Balancán, alt. 150 m, 2-4 Apr 1976, J.T.Calzada 2345 (F, MEX, MO).