Symplocos tacanensis Lundell (1939: 601)

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

30. Symplocos tacanensis Lundell (1939: 601) . Type:— GUATEMALA. N slope of Volcán de Tacaná , [15°09′N, 92°09′W], 2100 m, 2 April 1939, E. Matuda 2976 (holotype MICH-1192787-n.v., online image!, isotypes A!, CAS!, F!, GH!, K-644495-n.v., online image!, MEXU-2!, MO!, NY!, US!)

Trees 9–19 m tall; juvenile branchlets and vegetative buds densely hirsute, trichomes mostly 1.5–2.5 mm long, erect, ferruginous. Petioles 3–7 mm long; leaf blades bicolorous, oblong to lanceolate or lanceolate-oblong, 8–14 × 4–5.8 cm, subcoriaceous, abaxially hirsute, adaxially strigose when young and along major veins, secondary veins not adaxially impressed, base rounded to cordate, margins entire, apex acuminate. Inflorescences condensed racemes 1–1.5 cm long, 5–12-flowered; peduncle absent; rachis 3–4 mm long, densely hirsute, 1.5–2.5 mm long; bracts deciduous, ovate, 2–2.5 × 1–1.5 mm, densely hirsute, margins densely hirsute; bracteoles deciduous (but difficult to determine because of dense pubescence), 3–5, ovate, 1–2 × 1–1.5 mm, densely hirsute, margins densely hirsute; pedicels absent. Hypanthium densely hirsute. Calyx lobes 5, lanceolate, 3–4 × 2–3 mm, densely hirsute, margins densely hirsute. Corolla pink, 5-lobed, 7–10 mm long; tube 2–3 mm long; lobes adnate to filament tube for 4–5 mm, linear-oblong to oblanceolate, glabrous or sparsely sericeous distally. Stamens ± 4-seriate; filament tube 6–8 mm; distinct portions of filaments 1.5–2 × 0.5–0.75 mm wide. Disk pilose; style 8–10 mm long, pilose basally; stigma conspicuously and irregularly lobed. Fruits green maturing to dark bluish purple, cylindrical, 1.8–2.3 × 0.9–1.2 cm, hirsute, apex gradually narrowed to base of erect or slightly incurved calyx lobes; disk convex, apex partly visible, surpassed by calyx lobes; endocarp 3-locular, perimeter smooth to shallowly undulate.

Vernacular name —None.

Illustration — Figure 37 .

Phenology —Flowering February and April; fruiting November.

Distribution and habitat — Mexico (Chiapas) and Guatemala, in cloud forest, Cerro Boqueron and Volcán Tacaná at 2100–3100 m elev. Figure 26 .

Conservation status —This species is known from six collections representing four populations, all of which occur in the Cerro Boqueron and Volcán Tacaná area of southeastern Chiapas, Mexico, and adjacent Guatemala. None of the known populations are in a protected area. The EOO is 47 km ² and the AOO is 16 km ². In view of its rarity, local distribution, and deforestation threats in unprotected areas, we assign a classification of Critically Endangered (CR): B1ab(iv).

Discussion — Symplocos tacanensis can be recognized by the dense ferruginous pubescence covering its young branchlets, abaxial leaf surfaces, inflorescences, and sepals. The lanceolate sepals, large fruits, and densely congested inflorescences also distinguish this species from others in the area.

Additional specimens examined — MEXICO. Chiapas: on ridge NE of Cerro Boqueron on rd from El Rosario to Niquivil , 2255 m, [15°13′12″N, 92°18′W], 7 November 1986, Breedlove 65734 ( CAS!) ; on ridge NE of Cerro Boqueron on rd from El Rosario to Niquivil , 2255 m, [15°13′12″N, 92°18′W], 7 November 1986, Breedlove 65754 ( CAS!) ; on ridge NE of Cerro Boqueron on rd from El Rosario to Niquivil , 2255 m, [15°13′12″N, 92°18′W], 29 November 1986, Breedlove & Sigg 66007 ( CAS!) ; Unión Juárez, Volcán Tacaná, entre Talquian y la cima del Volcán , [15°06′45″N, 92°06′03″W], 19 June 1985, Martínez S. et al. 13177 (MEXU!, NY!) ; Motozintla, track from ejido Boqueron to Cerro Boqueron , 2400 m, 15°15′N, 92°17′W, 9 February 1990, Stafford et al. 359 (MEXU!, MO!) .

96 • Phytotaxa 264 (1) © 2016 Magnolia Press

KELLY ET AL.

A TAXONOMIC REVISION OF SYMPLOCOS

Figures

FIGURE 26. Geographic distribution of Symplocos pachycarpa and S. tacanensis.

FIGURE 37. Symplocos tacanensis. a. Branchlet with inflorescence. b. Close-up of (a) showing midvein pubescence of abaxial leaf blade surface. c. Inflorescence with flower buds. d. Flower. e. Corolla opened with attached stamens. f. Disk, style, and stigma. g. Fruit. h. Fruit, cross section. (a drawn from D. E. Breedlove 65734, CAS, D. E. Breedlove 65754, CAS, and E. Matuda 2976, CAS; b drawn from D. E. Breedlove 65734, CAS; c–f drawn from E. Matuda 2976, CAS; g, h drawn from D. E. Breedlove 65754, CAS.)