Name
Mariosousa acatlensis (Bentham) Seigler & Ebinger
Synonymy and types
Acacia acatlensis Bentham, London J. Bot. 1:513. 1842. - Senegalia acatlensis (Bentham) Britton & Rose, N. Amer. Fl. 23:112. 1928. - TYPE: Mexico, Puebla, Acatlan, May 1830, G.Andrieux 396 (holotype: K!, F photo!, MICH photo!, NY photo!, TEX photo!, isotypes: G!, US!).
Senegalia submontana Britton & Rose, N. Amer. Fl. 23:113. 1928. - TYPE: Mexico, Oaxaca, cerro San Antonio, alt. 1800 m, 12 Oct. 1907, C.Conzatti 2046 (holotype: US!, isotypes: F!, MEXU!, NY!). Britton and Rose (1928) listed the type as Conzatti 25,346. On the NY isotype, Britton wrote "the number of this specimen was erroneously printed 25,346".
Formal description
Shrub or small tree to 15 m tall. Bark dark gray, shallowly furrowed. Twigs light brown to greenish brown, not flexuous, glabrous to lightly puberulent. Short shoots absent. Leaves alternate, 50-150 mm long. Stipules herbaceous, light brown, narrowly linear, to 3 x 0.5 mm near the base, usually glabrous, persistent. Petiole adaxially shallowly grooved, 15-40 mm long, glabrous or nearly so, but commonly with minute purple glands; petiole gland solitary, located between the lower pinna pairs or along the upper half of the petiole, sessile, nearly circular to slightly elongated, 0.7-2.3 mm long, saucer-shaped to cup-shaped, glabrous, rarely absent. Rachis adaxially grooved, 20-110 mm long, glabrous to lightly puberulent and usually with minute purple glands, a sessile, cup-shaped gland, 0.4-0.9 mm across, between the upper pinna pair. Pinnae 7 to 30 pairs per leaf, 25-60 mm long, 3-7 mm between pinna pairs. Petiolules 1.0-2.4 mm long. Leaflets 36 to 60 pairs per pinna, opposite, 0.5-1.2 mm between leaflets, linear, 2.5-4.8 x 0.7-1.1 mm, glabrous and commonly light greenish-purple above, lateral veins obvious, a midvein and 1 to 2 smaller veins from the base, base oblique, margins ciliate, apex narrowly acute to acuminate. Inflorescence a loosely flowered cylindrical spike 40-100 mm long, 1 to 4 from the leaf axil. Peduncle 5-10 x 0.5-1.0 mm, glabrous to lightly puberulent and commonly with scattered minute purple glands. Involucre absent. Floral bracts linear, to 1 mm long, early deciduous. Flowers sessile, creamy-white; calyx 5-lobed, 1.0-1.6 mm long, lightly appressed pubescent; corolla 5-lobed, 2.1-2.8 mm long, lightly appressed pubescent; stamen filaments 4.5-6.5 mm long, distinct; ovary glabrous, on a stipe to 0.4 mm long. Legumes light to dark brown, straight, flattened, not constricted between the seeds, oblong, 80-170 x 13-25 mm, cartilaginous, transversely striate, glabrous, eglandular, dehiscent along both sutures; stipe to 20 mm long; apex broadly acute. Seeds uniseriate, no pulp, dark reddish-brown, oval, strongly flattened, 7-10 x 4.5-7.2 mm, smooth; pleurogram U-shaped, 1.2-2.3 mm across. Flowers: March-June. Chromosome number: Not determined.
Distribution
Dry, deciduous, tropical forests and thorn -scrub forests between 500 and 2100 m elevation in the states of Chiapas, Guerrero, Jalisco, México, Michoacan, Oaxaca and Puebla, Mexico.
Additional info
Mariosousa acatlensis is very similar morphologically to M. centralis. Both are widely distributed in southern Mexico, although M. centralis has been collected more frequently in the very south of Mexico and, unlike M. acatlensis, it occurs across the border in Guatemala and countries to the south. These two taxa are difficult to separate, and it is possible that they should be considered as subspecies of a single species. The two can be separated based on the presence or absence of minute purple glands that are common at the base of the leaflets, in the grooves of the rachis and petiole, and not uncommonly along the axis of the inflorescence in M. acatlensis. On young leaves these glands are extremely common, becoming less abundant on mature leaves, some becoming deciduous as the leaves mature. Rarely these glands are clear, lacking the purple color, but are easily observed under magnification. None of these glands were found on specimens of M. centralis examined. No other characteristic could be found that consistently separate these two species, though most specimens of M. centralis have leaflets with long hairs at the base on the ventral surface. These hairs are particularly evident on young leaflets, sometimes falling-off as the leaflets mature.
Mariosousa acatlensis is also similar to M. usumacintensis, differing by having narrower leaflets (less than 1.1 mm across) and lacking the large flattened petiolar gland of that taxon. Mariosousa acatlensis is sympatric with M. sericea and M. mammifera in Oaxaca; these two taxa also have minute purple glands on the leaves. Mariosousa acatlensis is easily separated from M. mammifera, which has fewer than 33 pairs of leaflets per pinna, leaflets that are commonly more than 1.5 mm wide, and a stalked petiolar gland. The dense, erect pubescence of M. sericea petioles and fruits usually separates this species from M. acatlensis. These species may occasionally hybridize where they are sympatric. In the northern parts of its range in Guerrero, Jalisco and Michoacan, M. acatlensis is sympatric with, and possibly hybridizes with, M. salazari. The minute glands, the large number of leaflets per pinna pair (more than 36), and the short petiolules (less than 2.5 mm long) separate it from that taxon.
Flowering time
March-June.
Representative specimens
MEXICO:
Chiapas:
- a 4 km al SW de Tolimán, Mpio. Motozintla de Mendozo, alt. 750 m, 10 Mar 1981, M.Sousa, T.Ramamoorthy, L.Cortes & H.Hernández 11824 (MO, TEX);
Guerrero:
- Pasando el Puente del Río Amacuyac, en Atenango del Río rumbo a Copalillo, alt 780 m, 29 May 1976, A.Delgado S. .A.Campomanes & O.Téllez 181 (CAS, MICH);
- Coyuca-Rosario, 4 Apr 1934, G.B.Hinton 5874 (GH);
- Coyuca-Chamerito, 26 Apr 1934, G.B.Hinton 5955 (GH, NY);
- Chacamerito, Coyuca Dist., 13 Jul 1934, G.B.Hinton 6286 (GH, MICH, NY, UC);
- Pungarabato, Coyuca Dist., 10 May 1935, G.B.Hinton 7749 (GH, NY);
- Tario, Coyuca Dist, 11 May 1935, G.B.Hinton 7755 (DS, GH, MICH, Y, US);
- en el Puerto El Salado, a 7 km al N de Tlapa camino a Huamuxtitlán, alt. 1100 m, 25 Jun 1982, E.Martínez S. 1070 (MO, TEX);
Jalisco:
- canopy dominant, Reserva Biosfera Sierra de Manantlán. steep slope W side of Cerro Grande, alt. 1500-1800 m, 13 Aug 1994. T.S.Cochrana & F.J.Santana M. 13038 (WIS);
- 1 km E of the Puerto Vallarta, 13 May 1991, E.J.Lott, A.Sanders, B.Phillips, T.Daniels & M.Ayala 3502 (NY, TEX);
- limite entre Jalisco y Michoacán, mpio. de Jilotlán de los Dolores, alt. 400 m, 10 Aug 1987, R.Ornelas U., A.Flores M. & A.Alvarado C. 1112 (WIS);
- 2 km al W de El Mirador, 10 km al NE de El Corcobado, carr. Autlán-Guadalajara, 18 Mar 1980, J.A.S.Magallanes 2169 (MO);
- a 20 km al NW de San Patricio, 2 Jul 1980, A.S.Magallanes 2420 (MO);
- 20 km NE of Autlán, alt. 1200 m, 27 Mar 1965, R.McVaugh 23271 (MICH, MO, NY);
- cerro a W del crucero de Teocuitatlán, 26 Jul 1994, S. Valencia D. 38 (MEXU);
- Barranca de Los Tanques, desv. al camino San Martín de las Cañas, alt. 1100 m, 3 Mar 1974, L.M.Villarreal 6121 (MICH);
México:
- Pungarancho, Temascaltepec Dist., 5 Apr 1933, G.B.Hinton 3747 (F, GH, MO, NY, US);
- Chorrera, Temascaltepec, alt. 1100 m, 29 Dec 1933, G.B.Hinton 5417 (F, GH, NY, US);
Michoacán:
- Rivas du Río Balsas, Los Camarones, 30 Apr 1898, E.Langlasse 112 (F, GH, US);
- 3 km al S de Jungapeo, alt. 1550 m, 16 May 1985, J.C.Soto N., S.Aureoles C., G.Silva & C.Pzarras 8573 (MEXU);
Oaxaca:
- 5 km sobre la desv. a Barranca de Los Calabazos, alt. 1040 m, 14 May 1987, R.Aguilar S. 220 (NY);
- 3 km al NE de Tonala, carretera a Huajuapan, alt. 1320 m, 9 Feb1993, J.I.Calzada & A.Campos 18320 (CAS, MICH, MSC);
- 5.5 km al NW de San Sebastián Frontera, alt. 1750 m, 14 May 1981, F.Chiang, F.G.Medrano, P.Davila, J.L.Villaseñor, P.Ruíz, R.Lemus, A.Valiente & F.Pliego F-1896 (MO);
- cerca San Antonio, alt. 1800 m, 12 Oct 1907, C.Conzatti 2046 (F, MEXU, US);
- cave area near Mitla, near Pass to Díaz Ordaz, alt. 1926 m, 6 May 1966, A.V.T.Kirkby 10 (US);
- 2.5 km al N de Yosocuta en la carretera Huajuapán-Juxtlahuaca, 5 Jul 1976, A.S.Magallanes, R.Ramos & E.S.Magallanes 11 (CAS, LL, MO);
- 3 km al NW de Santo Domingo Tonala, carretera a Huajuapan, alt. 1320 m, 27 Apr 1993, E.Ortíz-Bermudez 291 (MEXU);
- Tomellin Canyon, alt. 3000 ft., 17 May 1894, C.G.Pringle 5885 (GH, MICH, US, VT);
- cerca de Tonala, alt. 1350 m, 4 Jul 1977, J.Rzedowski 34920 (CAS, MO);
- a 12 km al N de Tonaltepec, alt. 1100 m, 25 Nov 1977, M.Sousa & A.S.Magallanes 8917 (UC);
- a 10 km al NW de Tamazulapán, alt. 1800 m, 14 Apr 1976, M.Sousa, O.Téllez & A.S.Magallanes 5432 (UC);
- 7 km al SW de Huajuapán de León, alt. 1600 m, 15 Apr 1976, M.Sousa, O.Téllez & A.S.Magallanes 5444 (CAS, US);
- 18 km al SW de Tamazulapán, alt. 1760 m, 29 Apr 1976, M.Sousa, O.Téllez & A.S.Magallanes 5689 (US);
- a 4 km al NW de Tamazulapán, alt. 1900 m, 18 Oct 1977, M.Sousa, O.Téllez & R.Grether 8235 (CAS, UC);
- Subida a las Ruinas del Cerro Guiengola, 29 Jun 1987, M.L.Torres C., R.Torres, L.Cortez & C.Martínez 928 (MO);
- Ladera oriente del Cerro Guiengola, alt. 720, 13 Jun 1986, M.L.Torres C., R.Torres, O.Téllez & C.Martínez 400 (MO);
- Puente Río del Oro, 3 km al NW de Tamazulpán, alt. 1900 m, 12 Apr 1987, R.Torres C., A.García M. & L.Cortes 9582 (MO);
- "La Junta", 8 km al SW de Huajuapán de Leon, 3 Apr 1982, R.Torres C. & P.Tenorio L. 172 (MO);
- ca 10 km al N de Tamazalapán, a Río del Oro, 11 May 1981, R.C.Trigos, D.Lorence & A.García M. 793 (F, MO);
- 14 km al SW de Huajuapán, carretera Huajuapán a San Antonio Atenango, alt. 1600 m, 18 Jun 1982, R.C.Trigos & R.Torres1419 (CAS, MO);
Puebla:
- Sn. Sebastian Tenango, 15 May 1966, W.Boege 94 (GH);
- Tepeji de Rodríguez, alt. 1575 m, 20 Jan 1985, R.S.Felger 85-38 (MO);
- Paraje Caballo Pintado, Cerro Teponaxtle, Mpio. Izucar de M., alt. 1340 m, 25 Jul 1982, E.Guizar 932 (MEX);
- Puente de Dios, 2 km al W de Molcaxac, 28 Jun 1982, F.G.Medrano, B.González & D.Nava 12733 (MO);
- Puente de Dios, 2 km al W de Molcaxac, 28 Jun 1982, F.G.Medrano, B.González & D.Nava 12736 (CAS, MO);
- 3.6 km, 11o al SE de Tepeyahualco, alt. 1950 m, 29 Jul 1982, D.Nava, F.Nava & F.Castillo 28 (MO);
- 3 km al SW de Hirziltepec, alt. 1900 m, 10 Oct 1982, D.Nava, A.Alazanez & S.Jardon 97 (NY);
- 20 miles NW of Acatlán on hwy. 190, 5 Jul 1986, D.S.Seigler & B.Maslin 12690 (EIU, ILL);
- 20 miles NW of Acatlán on hwy. 190, 5 Jul 1986, D.S.Seigler & B.Maslin 12691 (EIU, ILL);
- 29 miles SE of Acatlán on hwy. 190, 5 Jul 1986, D.S.Seigler & B.Maslin 12692 (EIU, ILL);