Symplocos austromexicana Almeda (1976: 365)

Kelly, Lawrence M., Almeda, Frank & Fritsch, Peter W., 2016, A taxonomic revision of Mexican and Central American Symplocos (Symplocaceae), Phytotaxa 264 (1), pp. 448-450 : 448-450

5. Symplocos austromexicana Almeda (1976: 365) . Type :— MEXICO. Oaxaca: ca. 27 mi N of Ixtlán de Juárez off of Hwy. 175 in wet pine-hardwood forests, ca. 2575 m, [17°27′15″N, 96°30′28″W], 20 December 1972, F. Almeda & J. Luteyn 1659 (holotype DUKE!, isotype CAS!)

Shrubs 1–4 m tall; juvenile branchlets and vegetative buds sparsely strigillose, trichomes 0.2–0.4 mm long, antrorsely appressed, light brown or whitish. Petioles (1–)2–3(–4) mm long; leaf blades slightly bicolorous, ovate to elliptic-ovate, (0.6–)1–1.7(–2.6) × 0.5–0.9(–1.1) cm, coriaceous, glabrous, secondary veins not adaxially impressed, base acute, margins entire, apex obtuse to rounded. Inflorescences 1-flowered; peduncles 2–4 mm long; bracts and bracteoles not readily distinguishable, caducous, 3–5, distributed from the base of the flower and farther down along peduncle, oval or oblong (rarely triangular or subulate), 1–1.5 × 0.5–1 mm, glabrous, margins finely ciliate. Hypanthium sparsely to moderately strigillose or occasionally glabrous. Calyx lobes 4 or 5, ovate to suborbicular, 2–3 × 1–2 mm, glabrous, margins finely ciliate, often glandular. Corolla purple or lavender, 6–7- lobed, 6–7 mm long; tube ca. 1 mm long; lobes adnate to filament tube for 2–3 mm, oblong, glabrous. Stamens triseriate; filament tube 2–4 mm long; distinct portions of filaments 0.5–2 mm × 0.25–0.5 mm. Disk pilose; style 5–7 mm long, glabrous; stigma shallowly to deeply 3-lobed. Fruits green maturing to dark bluish purple, broadly ovoid to oblong-ellipsoid, 9–12 × 4–8 mm, glabrous, apex gradually narrowed to base of erect calyx lobes; disk pulvinate, apex partly visible, surpassed by calyx; endocarp 3-locular, perimeter slightly undulate.

Vernacular name —None.

Illustration — Almeda (1976: 23).

Photographic images — Figures 1b , 2e .

Phenology —Flowering January, July, August, October, and November; fruiting March, May, July, and August.

Distribution and habitat — Mexico (north-central Oaxaca), in Quercus-Pinus forests and cloud forests at 2575–2880 m elev. Figure 7 .

Conservation status —This species is known only from about 12 localities in a narrow elevational band in the mountains north of Oaxaca, Mexico. The EOO is 352 km ² and the AOO is 44 km ². The area of occurrence is experiencing habitat destruction and deforestation and is therefore inferred to be in decline. We assign a classification of Endangered (EN): B1ab(iii).

Discussion —This Oaxacan endemic is easily distinguished from all other Mexican and Central American species by the combination of small leaves, solitary, glabrous flowers, and small fruits (9–12 mm long).

Additional specimens examined — MEXICO. Oaxaca: between Oaxaca and Valle Nacional , 44 km N of Ixtlán de Juárez, 2750 m, [17°33′33″N, 96°31′05″W], 22 October 1985, Bartholomew et al. 3308 (CAS!, GH!, MEXU!, MO!, NY!) ; Mpio. Comaltepec, to the right of Hwy 175, just beyond first major switchback on descent from mirador below Cerro Humo Chico , 2740–2760 m, 17°35′15″N, 96°31′30″W, 1 November 1993, Boyle & Massart 2482 (CAS!, MO!) ; NW slope of Cerro Humo Chico, 43 km N of Ixtlán de Juárez jct. on rd to Valle Nacional , 2870 m, [17°35′07″N, 96°30′44″W], 9 November 1983, Breedlove & Almeda 59968 (C!, CAS!, F!, GH!) ; NW slope of Cerro Humo Chico, 43 km N of Ixtlán de Juárez jct. on rd to Valle Nacional , 2870 m, [17°35′07″N, 96°30′44″W], 9 November 1983, Breedlove & Almeda 60011 (CAS!, MEXU!, MO!, NY!) ; Sierra de Juárez, carretera Oaxaca a Tuxtepec , cerca de Cerro Pelón , a 300 m antes de la desviación a San Pedro Yolox , 2850 m, [17°34′33″N, 96°30′35″W], 19 January 1989, Cházaro B. et al. 5810 (CAS!, MEXU!) ; 10.8 km en línea recta al S de Santa Cruz Tepetotutla , 2660 m, 17°38′48″N, 96°31′26″W, 21 May 1994, Gallardo H. et al. 1127 ( MEXU!) ; 11.2 km en línea recta al S de Santa Cruz Tepetotutla , 2800 m, 17°38′49″N, 96°32′26″W, 12 July 1994, Gallardo H. et al. 1138 ( MEXU!) ; 2 km S of the summit of Cerro Pelón, ca. 46 km N of Ixtlán de Juárez, along hwy to San Pedro Yolox, ca. 100 m W of jct. with hwy from Valle Nacional to Oaxaca City, 2878 m, 17°34.510′N, 96°30.586′W, [17°34′41″N, 96°30′39″W], 11 January 2003, Kelly et al. 1304 (CAS!, MEXU!, NY!) . Cerro de Humo Chico–Comaltepec , 3000 m, [17°33′12″N, 96°31′20″W], 27 January 1963, MacDougall s.n. (CAS-2!, MEXU!) ; Cerro de Humo Chico, near Paso Cerro Pelón , 9500 ft, [17°35′N, 96°30′33″W], 2 September 1966, MacDougall 15 (NY!, US!) ; Dist. Ixtlán, Cerro Humo Chico, Comaltepec , 9500 ft, [17°34′51″N, 96°29′40″W], 27

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January 1967, MacDougall s.n. ( CAS!); Cerro de Humo Chico , [17°34′22″N, 96°30′22″W] , 8 February 1966, MacDougall 19 (NY!, US!); Mpio. Comaltepec , Dist. Ixtlán, Cerro Pelón , 14 November 1968, MacDougall 484S ( NY!); Llano de las Flores, Sierra de Juárez, [17°26′42″N, 96°30′06″W] , 3 January 1960, Miranda 9239 ( MEXU!); sobre la brecha 290, Macuiltianguis , 2950 m, [17°32′02″N, 96°33′04″W] , 20 March 1980, Pérez C. 67 ( MEXU!); Sierra Juárez , above Valle Nacional, 9000 ft, [17°46′30″N, 96°18′11″W] , 26 December 1970, Sharp 717 ( NY!); Cerro Pelón , desv. a San Juan Yolox, 2800 m, [17°34′54″N, 96°30′55″W] , 18 January 1989, Tenorio L. et al. 15452 (F!, MEXU!); Sierra Madre Oriental , ca. 0.5 mi S of Cerro Pelón, 3000 m, [17°34′45″N, 96°30′37″W] , 30 August 1975, Webster et al. 20292 ( MEXU!) .

Figures

FIGURE 1. Flowers of some species of Mexican and Central American Symplocos. a. S. longipes (photograph by Victor Steinman). b. S. austromexicana. c. S. breedlovei. d. S. coccinea. e. S. costaricana (photograph by Daniel Solano). f. S. hartwegii. g. S. nigridentata. h. S. povedae.

FIGURE 2. Flowers and fruits of some species of Mexican and Central American Symplocos. a. S. serrulata. b. S. speciosa. c. S. striata. d. S. tribracteolata. e. S. austromexicana. f. S. citrea. g. S. pycnantha. h. S. coccinea. i. S. serrulata. j. S. hartwegii.

FIGURE 7. Geographic distribution of Symplocos abietorum, S. austin-smithii, and S. austromexicana.