Magnolia darioi 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 : 123-125

Magnolia darioi A.Vázquez & D.L.Kelly , sp. nov. ( Figs. 9–10 )

Type:— HONDURAS. Depto. Cortés: 1150 m from the start of Cantiles transect 2 (trail to Cerro Jilinco), Parque Nacional Cusuco , Sierra del Merendón , W of San Pedro Sula, montane rainforest, 15°30’54.69” N, 88°13’49.61” W, 2150 m, 07 Jul 2019 (fl), Ward, Rodwell, Haelewaters & Cole CUCA2019 (holotype: IBUG!; isotypes: BIGU!, CR!, EAP!, HEH!, HEM!, MO!, NY, P!, TEFH!, TCD!) .

Magnolia darioi i s similar to M. hondurensis but differs in its adaxially pubescent leaves and pubescent to puberulous fruits, pustular bark and scabrous vs. smooth, leaves narrowly oblanceolate to narrowly elliptic, strongly discolorous and flat vs. elliptic, oblanceolate or lanceolate, non-discolorous and abaxially convex, peduncles longer 2.6–4.3 vs. 0.8–2.3 cm peduncles sparsely pubescent with amber hairs, hairy around stipular ring-scars with a narrow zone of dense hairs just below the flower vs. densely tawny pubescent, carpels felty pubescent vs. glabrous or slightly pilose.

Trees ca. 15.0–28.0 m tall, (19.0–)36.0–46.0 cm dbh (one individual forked at the base); bark pustular, slash yellow, sweetish odour, no exudate; vegetative twig internodes 0.25–0.9(–1.5) × 0.25–0.55 cm, twigs varying from glabrous to having patchy or scattered hairs to being +/- densely hairy (hairs +/- ascendant, amber (i.e. pale orange-brown), twigs proximally blackish in dried material, raised whitish oval vertically-elongated lenticels prominent, stipules free from the petiole to 1.75 cm long in (apparently) resting buds, to 3.7 cm long in actively growing shoot, surface finely rugose and with scattered amber hairs. Stipular ring-scars prominent. Petioles 0.9–2.4 × 0.15–0.2 cm, glabrescent to glabrous, expanded at base, material blackish when dried, irregularly ridged, furrowed. Laminas 4.0–12.4. × 1.1– 4.5 cm, narrowly oblanceolate to narrowly elliptic, margins plane or slightly wavy, apex usually obtuse to rounded, rarely subacute, usually acute at the base, glabrescent, abaxially pubescent when young, pubescence of ascending amber hairs, completely concealing the lamina, strongly discolorous when dried, adaxially dark brown, abaxially pale, whitish, midrib abaxially forming a prominent ridge, adaxially marked as a shallow groove. Secondary leaf veins 17–18 per side, adaxially with a sparse indumentum of spreading, translucent hairs, not concealing the lamina, abaxially pilose in the distal shoots of the fully expanded leaves with dense spreading amber hairs on and alongside the midrib, inconspicuous sparsely scattered hairs on the rest of the lamina, adaxial sides with inconspicuous whitish hairs mainly confined to the channel that overlies the midrib. Proximal parts of the shoot with leaves are nearly glabrous on both surfaces with a strong spicy odour. Peduncle 2.6–4.3 × 0.4–0.45 cm, longitudinally ridged, pubescent with amber hairs around stipular ring-scars, with a narrow zone of dense hairs just below the flower, peduncular internodes 2–3. Hypsophylls 2, broadly ovoid, densely goldish pubescent, shed before anthesis. Flower bud 5.3 cm long (hypsophylls shed). Open flower ca. 10–12.5 cm in diam., trimerous, creamy white, with a strong sweet scent (“the aroma was really wonderful”: Alan Ward), sepals 3, 5.45–6.00 × 2.10–3.20 cm, slightly obovate, outer petals 3, 5.60–5.95 × 2.40–3.20 cm, broadly obovate, rounded at apex, inner petals 3, 4.6–6.1 × 1.6–2.3 cm, obovate, stamens 70, 0.95–1.4 cm long, acuminate at apex. Gynoecium ellipsoid, 2.6 cm long, carpels 30, lowermost carpel 1.4 cm long. Ovaries initially fused to the axis of the receptacle and one another before dehiscence, pubescent, locules smooth-walled, each containing 2 ovules, style glabrous, stigma curved, the abaxial surface concave and smooth, adaxial surface convex and strongly papillose. Developing fruit woody, ellipsoid, with thickly scattered hairs and scars of broken-off stigmas visible, locules smooth, each containing two developing seeds, thread-like suspensory fibrils visible. Fruit 3.5 × 2.8 cm, ellipsoid to ovoid; carpels felty pubescent, seeds 8.5 × 6.0 mm, round, orange.

Distribution, ecology and phenology:— Endemic to the Sierra del Merendón, Parque Nacional Cusuco, confined to high elevations between Cerro Cantiles and Cerro Jilinco (Cortés Province) in montane rainforest with trunks covered with a lush growth of bryophytes, 1850–2150 m ( Fig. 1 ; Table 2 ). Companion species include Podocarpus oleifolius Don (1824: 20) (Podocarpaceae) , Gentlea micranthera ( Donnell Smith 1893: 205) Lundell (1968: 69) (Primulaceae) , Ilex guianensis ( Aublet 1775: 88) Kuntze (1891: 113) (Aquifoliaceae) . Vaccinium poasanum Donnell Smith (1897: 395) and Bejaria aestuans Mutis in Linnaeus (1771: 242) (both Ericaceae ), the last two have been recorded as components of the canopy in ridge-top bosque enano (elfin forest). Flowering July, fruiting March.

Conservation status:— Critically endangered (CR), IUCN criterion B1ab(iii). This species is known from a small number of individuals, apparently sparsely scattered across a restricted geographical area, an extension of occurrence (EOO) of 0.621 km 2, and an area of occupancy (AOO) of 8 km 2 ( Table 1 ). It is recorded within a narrow elevational range, close to the highest levels of the Sierra del Merendón. Its location and elevation make it relatively safe from illegal logging but vulnerable to the impacts of climatic warming. Upslope shifts in the bird communities of Cusuco National Park have already been reported over the ten-year period 2007–2016 ( Neate-Clegg et al. 2018).

Etymology:— Honouring Darío Mejía (Darío Alberto Mejía Valdivieso), university professor, forester,independent researcher Celaque Asesores S. De R.L de C.V., general manager, explorer, enthusiastic field guide and collector of valuable specimens of Honduran Magnolia (1992, 1993, 1994, 2021), including the discovery of this species in fruit (Mejía 345) in March 1993 and the type specimen of Magnolia cochranei (Mejía 356).

Additional specimens examined:— HONDURAS. Depto. Cortés: Sendero a Cerro Jilinco, filo entre Cerro Cantiles y Cerro Jilinco, 20 km W of San Pedro Sula, Parque Nacional Cusuco , 15°30’N, 88°14’W, 2120 m, 20 Mar 1993 (fr), Mejía 345 ( EAP, HEH, MO, TEFH) ; SW-facing slope, angle ca. 24°, plot 26, by trail S of Quebrada de Cantiles, Parque Nacional Cusuco, Cordillera Merendón , W. of San Pedro Sula , 1850 m, 15.51090280° N, 88.238113890° W, 30 July 2004 (sterile), Kelly et al. 26/384 ( TCD, TEFH) ; same tree as type collection, SW-facing slope, angle 28°, plot CA2/SS4, 1150 m along Cantiles transect 2 (trail to Cerro Jilinco), Parque Nacional Cusuco , Sierra del Merendón , 2150 m, 15.515191666° N, 88.230447220° W, 3 Jul 2011 (sterile), Kelly & Dietzsch CA 2/SS4/81 ( TEFH)

Figures

FIGURE 1. Geographic distribution of Honduran Magnoliaceae.

FIGURE 9. Magnolia darioi. A. Fruit with pubescent follicles. B. Flowering tree branch. C. Bark of upper trunk (showing damage by sapsucker Sphyrapicus varius, ‘Carpintero de Paso’). D. Top flowering branches. E. Leaves abaxially glaucous with reddish pubescence. Photographs A, B, and E by Tom Martin, C and D by Alan Ward.

FIGURE 10. Magnolia darioi. A. Developing fruit.B. Fruit showing one seed and dorsal dehiscence. C. Vegetative shoots (Kelly 26/384). D. Leaves abaxially glaucous (left) and adaxially dark green (right); with a densely hairy spathaceous bract and gynoecium and stamens in between. Photographs by A. Vázquez.