Magnolia juninensis F. Arroyo 2014, sp. nov.
Creators: name: ARROYO, FRANK
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Magnoliales
Magnoliaceae
Magnolia
Magnolia juninensis

description: Magnolia juninensis F.Arroyo, sp. nov.
Type:— PERU. Junin: Provincia Chanchamayo, Distrito San Ramon, bosque Puyu Sacha, 11°05’ S, 75°25’W, 2150 m, 02 September 2011, Arroyo & Quispe 234 (holotype MOL!; isotype USM!).(Fig. 1)
Trees to 25 m high, branchlets covered with deciduous greyish hairs; leaf blades elliptic to suborbiculate, apex emarginate to rounded, base obtuse, glabrous adaxially, lanose abaxially; flowers solitary, hypsophylls 3, sepals 3, externally pubescent, petals 8; stamens ca. 50; gynoecium with up to 25 carpels; fruit ellipsoid, pubescent.
Trees to 25 m tall; outer bark greyish, slightly fissured and profusely lenticellate, inner bark yellowish, with strong characteristic smell; branchlets terete or slightly compressed, lenticellate, 0.6–1.3 cm in diameter, distally with grey pubescence (turning yellowish to tan on drying) of simple hairs especially covering vegetative buds and floral peduncles, becoming glabrous with age. Petioles 1–3 cm long, glabrescent, semiterete, with flat or concave adaxial scar covering up to 75% of their length. Leaves elliptic to suborbicular or sometimes obovate, 9–20 × 5–14 cm, bright to dark green and glabrous above, densely covered with hirsute grey pubescence beneath especially on midrib and lateral veins, apex rounded, emarginate or obtuse (acute in leaves of younger shoots), margin entire, base obtuse to cuneate; lateral veins 10–17 on each side of midrib, brochidodromous, plane to slightly raised above, raised beneath, tertiary venation prominulous or obscure on both surfaces, or usually obscure beneath due to the dense pubescence. Stipules 2.5–9.6 cm long, densely pubescent, becoming glabrous with age. Flowers terminal, solitary, fragrant with fruity smell; hypsophylls 1–3, pubescent; sepals 3, creamy white to pale yellow, 2.9–3.2 × 2.0– 2.1 cm, broadly elliptic, concave, chartaceous, externally pubescent only from the base up to the middle, apex obtuse; petals 8, fleshy, creamy white to pale yellow, the outer ones 3.25–4.10 × 1.50–2.00 cm, obovate, cochleariform, apex obtuse, rounded or emarginate, the inner ones 3.0–3.7 × 1.1–1.4 cm, elliptic, cymbiform, apex acute; stamens linear, ca. 50, 1.0–1.5 × 0.2 cm; gynoecium ellipsoid, 1.8–2.2 cm long, carpels 19–25, longitudinally ribbed, pubescent except on the extrorse stigmas. Fruit ellipsoid to obovoid, 3.7–6.0 × 2.1–3.8 cm, greenish to tan, pubescent, with circumscissile dehiscence; seeds not seen.
Phenology:— Flowering June to December; fruiting September and November at the beginning of the rainy season.
Distribution and Habitat: — Magnolia juninensis is found in primary humid forests in the regions of Pasco and northern Junin between 2000–2500 m, growing mostly on moderate to steep slopes with soils rich in organic matter. It is often found in association with Hieronyma macrocarpa Müll. Arg. (Euphorbiaceae), Retrophyllum rospigliosii (Pilg.) C.N. Page (Podocarpaceae), Cecropia spp. (Urticaceae), Coussapoa sp. (as a strangler, Urticaceae), Ficus trigona L.f. (Moraceae), Schefflera sp. (Araliaceae) and Ceroxylon sp. (Arecaceae).
Discussion:— A closely related species is Magnolia gilbertoi (Lozano, 1983: 73) Govaerts (1996: 30) from Colombia. The main differences between them are the number of lateral leaf veins (10–17 on each side of the midrib in M. juninensis vs. 17–21 in M. gilbertoi), number of petals (8 vs. 6, respectively), shape of petals (obovate or elliptic vs. obovate only, respectively), shape of stigmas (strongly extrorse vs. straight or slightly extrorse, respectively) and a greater number of stamens (ca. 50 vs. 34, respectively) and carpels (25 vs. 11, respectively). Another similar species is Magnolia yarumalensis (Lozano, 1983: 46) Govaerts (1996: 72), which differs from M. juninensis in its petioles without an adaxial scar, and greater number of stamens (89 in M. yarumalensis vs. ca. 50 in M. juninensis) each with an apical filament-like appendage not found in M. juninensis.
Etymology:— The species epithet refers to Junin, the region of the type locality.
Additional specimens examined:— PERU. Junin: Prov. Chanchamayo, San Ramón, Alto Pichita, fundo Vista Alegre-APRODES, 11°05’ S, 75°25’W, 2150 m, 30 September 2002, Daza & Reyna 2832 (MOL). Pasco: Prov. Oxapampa, Dist. Huancabamba, Zona de Amortiguamiento del Parque Nacional Yanachaga-Chemillen, sector Oso-Playa, 10°19’S, 75°34’W, 2410 m, 24 September 2007, Monteagudo et al. 15263 (HOXA, USM); Zona de Amortiguamiento del Parque Nacional Yanachaga-Chemillen, sector Oso-Playa, 10°17’S, 75°36’W, 2200 m, 11 June 2008, Monteagudo et al. 16364 (HOXA USM); Oxapampa, Parque Nacional Yanachaga-Chemillen, cercanías de refugio El Cedro, 10°32’S, 75°21’W, 2240 m, 24 November 2002, Monteagudo et al. 4421 (HOXA, USM).
description: Published as part of ARROYO, FRANK, 2014, A new species of Magnolia (Magnoliaceae) from central Peru, pp. 220-222 in Phytotaxa 167 (2) on pages 220-222, DOI: 10.11646/phytotaxa.167.2.14, http://zenodo.org/record/5138767