Magnolia cusucoensis A.Vázquez & D.L.Kelly, 2022

Vázquez-García, J. Antonio, Kelly, Daniel L., Mejía-Valdivieso, Darío A., Morales, Wilson, Dahua-Machoa, Alex, Vega-Rodríguez, Hermes, Peña, Alondra Salomé Ortega, Padilla-Lepe, Jesús & Muñiz-Castro, Miguel Á., 2022, Magnolia (Magnoliaceae) in Honduras: a synopsis with six new taxa, Phytotaxa 570 (2), pp. 109-149 : 121

Magnolia cusucoensis A.Vázquez & D.L.Kelly , sp. nov. ( Fig. 8 )

Type:— HONDURAS. Depto. Cortés: Parque Nacional Cusuco, south of Campamento El Cortecito (75 m along trail CO4), Sierra del Merendón , W of San Pedro Sula, 15°30’43.91”N; 88°17’17.65”W, 1599 m, 16 July 2006 (st.), Kelly, Hernández & Munguía CO /4/MS/970 (holotype: TCD!; isotypes: TEFH!, IBUG!, BM!) .

Magnolia cusucoensis overlaps to some degree with M. hondurensis in terms of petiole length and blade size and shape, but it differs in having fewer lateral leaf veins per side, 6–8 vs. 12–19, abaxially glabrous vs. abaxially pubescent leaves, 32–36 vs 61–93 stamens and 2–14 vs. 23–38 carpels.

Trees ca. 20 m tall, (10.0–)13.0–27.0 (–38.0) cm dbh. Bark strongly pustular with prominent crater-like horizontally elongate lenticels, slash yellowish to orange, aromatic, twig internodes 0.5–3 × 0.2 –0.4 cm, glabrous, stipules free from the petiole. Leaves when crushed with cinnamon or cardamom odour, petiolate, petioles 0.6–1.7 cm, glabrous, laminas 4.6–12 × 1.7–5.6 cm, narrowly oblanceolate, acute at the base and apex, glabrous, lateral nerves per side 6–8. Flowers terminal, solitary, colour unknown, peduncular internodes 2–3, 0.4–1.6 × 0.2–0.4 cm, pubescent at the nodes to glabrescent, hypsophylls 1–2, flower bud ovoid-ellipsoid, 1.3 × 0.8 cm, brownish, with shiny pubescence, slightly pubescent at the margins, apex, and base, sepals 3, petals 6, stamens 32–36, gynoecium ellipsoid, with 12–14 carpels, blackish after drying. Fruits ovoid to oblongoid, glabrescent, seeds nigrescent.

Habitat and phenology:— Growing in broadleaved montane rainforest with many tree-fall gaps; the leading canopy species include Lauraceae ( Persea spp. ), Euphorbiaceae ( Hieronyma oblonga , Alchornea spp. ) and Fagaceae ( Quercus spp. ), 1408–1736 m ( Fig. 1 , Table 2 ). Flowering July, fruiting March.

Etymology and ethnobotany:— Named for the species-rich Cusuco National Park in north-western Honduras. The tree is locally known as canelillo/canelo [little cinnamon, cinnamon] (the names are also applied locally to Aiouea montana , Persea sp. and other Lauraceae and at least to one other Magnolia sp. ). Crushed leaves have a sweet cinnamon odour. It is also named as naranjo de montaña [mountain orange] (Kelly & Dietzsch CO4/SS2/143).

Notes:— Magnolia cusucoensis belongs to M. sect. Magnolia . It is easily recognised by having the smallest number of stamens and carpels of all Honduran magnolias in this section ( Table 3 ).

Conservation status:— Critically endangered (CR) with the extent of occurrence (EOO, minimum convex polygon) for M. cusucoensis restricted to ca. 16.23 km 2, and its area of occupancy (AOO) 24 km 2. Populations are severely fragmented, and there is a continuing decline in the extent and quality of their habitats. However, it is in a protected area, Cusuco National Park ( Table 1 ).

Additional specimens examined:— HONDURAS. Depto. Cortés: Sierra del Merendón, Parque Nacional Cusuco , Plot 7, near trail from Guanales to Base Camp, W. de San Pedro Sula, 15°29’20.48” N, 88°13’28.15” W, 1660 m, 12 Jul 2004 (fl, and young gynoecium), Kelly et al. 7/13 ( EAP, MO) ; SE of Campamento El Cortecito, W. of San Pedro Sula , 15°30’34.79” N, 88°16’55.85” W, 1736 m, 19 Jul 2008 (young gynoecium), Kelly et al. CO4/SS4/320 ( IBUG, TEFH) ; 1025 m from site of Campamento El Danto , W of San Pedro Sula, 15°31’16.46” N, 88°16’31.64” W, 1569 m, 14 Jul 2011 (sterile), Dietzsch DA 0/SS3/5987 ( TCD) . Plot GU 2/SS3, 1800 m by trail SE from Guanales camp-site, Parque Nacional Cusuco, Sierra del Merendón , W of San Pedro Sula, 1408 m, 29 Jun 2013 (sterile), Kelly & Dietzsch GU 2/ SS3/3487 ( HEH) ; Plot C 04/SS 2, 450 m along trail 4, SE of El Cortecito camp site, Parque Nacional Cusuco, Sierra del Merendón, Cortés Province, W of San Pedro Sula , 1611 m, 6 Jul 2013, (sterile), Kelly & Dietzsch CO 4/SS2/143 (EAP) ; Base Camp , Parque Nacional Cusuco , Sierra del Merendon, W of San Pedro Sula, 1595 m, 15°30’11.22” N, 88°12’44.38” W, 25 Jul 2004 (sterile), Lennkh & Hernández 10/205 ( TEFH) ; Plot DAO/SS3, 1025 m by trail S from El Danto camp site, Parque Nacional Cusuco, W of San Pedro Sula, 1569 m, 15°31’16.46” N, 88°16’31.64” W, 14 Jul 2011 (sterile), Dietzsch DAO/SS3/5979 ( IBUG) .

Figures

FIGURE 1. Geographic distribution of Honduran Magnoliaceae.

FIGURE 8. Magnolia cusucoensis. A–C. Leaf variability in size and shape. A. Kelly et al. CO/4/SS4/320. B. Kelly 970, and C. Kelly & Dietzsch CO/4/SS2/143. D. Hypsophylls. E. Peduncular internodes. F. Developing fruit. G. Gynoecium with broken stigmas, staminal, petal and sepal, and hypsophyll scars. Photographs by A. Vázquez.