Magnolia veliziana A.Vázquez, Tribouillier & Archila, 2021

Vázquez-García, J. Antonio, Tribouillier-Navas, Erick, Archila, Fredy, Véliz, Mario, Peña, A. Salome Ortega & Shalisko, Viacheslav, 2021, Three new species of Magnolia (Magnoliaceae) endemic to the north-wet-arc in the Maya Highlands of Guatemala, Phytotaxa 529 (1), pp. 57-70 : 64-66

Magnolia veliziana A.Vázquez, Tribouillier & Archila , sp. nov. ( Fig. 4 )

Type:— GUATEMALA. El Quiché: municipality of Chajul, Santa Clara , 1260 m, 15°42’36.89”N, 91°00’57.49”W, with Vochysia guatemalensis Lippia myriocephala, Licaria misantlae, Hedyosmum mexicanum , 12 Jun 2019 (fl, fr), Tribouillier & Archila MG-065 (holotype: BIGU; isotypes: AGUAT, BIGU, IBUG).

Magnolia veliziana belongs to M. sect. Magnolia and is similar to M. sororum from Costa Rica, differing from the latter in having glabrescent to glabrous twigs, petioles abaxially glabrous and adaxially glabrescent, leaves abaxially glabrescent, apex acuminate to cuspid (–acute), smaller flowers and petals, larger polyfollicles and more carpels ( Table 4 ). Another similar species is M. guatemalensis , from which it differs in having broadly obovate-oblong sepals to broadly elliptical, smaller length to width ratio, smaller flowers, larger fulvo-velutinous polyfollicles and more carpels and stamens.

Trees 10.0–15.0 m tall, 45.0–55.0 cm DBH; twigs glabrous to glabrous; petiole 1.6–3.1 cm long, canaliculate, abaxially glabrous, adaxially fulvo-pubescent to glabrescent; leaves (12.0–)14.0–22.6 × (4.9–) 7.1–9.4 cm, elliptical, narrowly elliptical to obovate (-lanceolate), apex acuminate to cuspidate (-acute), base acute to shortly decurrent (- obtusa), adaxially fulvo-pale glabrous to glabrous with pubescence mainly observed on the coast and at the base of the leaf, abaxially strigose glabrescent to glabrous, mainly on the coast, at the base and on the margin, pale orange trichomes; with 11–14 pairs of veins per side; flowers 10.5–13.0 cm in diameter; spathaceous bracts 2, adaxially glabrous, abaxially fulvo-strigose (–glabrescent), the external 4.5–4.6 × 4.6–5.6 cm, the internal 4.5–5.4 × 4.4–6.4 cm; peduncle 2.0–4.1 (1.9–3.3 corresponding to the largest segment) × 0.7–0.8 cm, thickly strigose light orange, then glabrescent; sepals 5.2–5.5 × 3.2–3.5 cm, greyish, broadly obovate-oblong to broadly elliptical, adaxially glabrous, abaxially sparsely fulvo-pubescent, then glabrescent; petals 6, white, the external 3, 5.4–5.9 × 2.9–3.2 cm, obovate, the internal 5.1–5.6 × 2.1–2.3 cm; narrowly obovate; staminophore (in flower) 0.6–0.9 × 0.5–0.7 cm, red; (in fruit) 0.8–1.0 × 0.8–0.9 cm, dark purple; stamens 103–111, 1.5–1.6 cm long; gynoecium 2.2–2.3 × 1.1–1.2 cm, ellipsoid, velutinous, the pubescence yellow-orange; polifollicles (6.8–)7.6–8.8 × (2.4–) 2.9–3.5 cm, oblong to ovoid-oblong, fulvo-velutinous, follicles 47–55(–58), 1.3–2.4 (0.3–0.4 corresponding to style) × 1.0– 1.3 cm; seeds with orange sarcotestas.

Distribution, phenology and ecology:— Known from one locality in Chajul Municipality, El Quiché, 1260–1600 m, in remnant cloud forest, flowering June–August, fruiting October–December.

Other specimens examined:— GUATEMALA. El Quiché: municipality of Chajul, Santa Clara , 1260 m, 15°42’36.89”N, 91°00’57.49”W, 21 Aug 2019 (fl, fr), Tribouillier & Archila MG-066, MG-067, MG-068, MG-069 (MEXU, NY); 230 m SW from the type locality, 15° 42’ 28.58”N, - 91° 0’ 50.11”W; 13 March 2020 (fl, fr), Tribouillier & Archila MG-053, MG-099 (BIGU) .

Etymology:— Named in honour of Ing. Agr. Mario Esteban Véliz Pérez (1964–), Coordinator-curator of the BIGU Herbarium, who has contributed substantially to the knowledge of the flora of Guatemala.

Conservation status:— This endemic species is considered critically endangered (CR), unofficially meeting criteria D of the IUCN (2019): the only known population includes less than 50 adult individuals sampled in the type locality and another nearby site less than 250 m distant.Additionally, the area of occupation can be described by a single minimal possible grid cell of 4 km ² because the species is endemic to the cloud forest of the municipality of Chajul. The actual and potential exploitation levels in the area remain high, since surrounding cloud forests are fragmented by logging for conversion from forest to pasture and agriculture, leading to the ongoing risk of destruction.

Figures

FIGURE 4. Magnolia veliziana A. Habit. B. Flower in the female phase. C, D. Flower in male phase E-H. Gynoecium and pubescence. F. Holotype. G. Polyfollicles after dehiscence. I. Seeds and dehiscing fruits. Photographs by E. Tribouillier.

Tables

Table 4. Comparison of Magnolia veliziana with M. sororum and M. guatemalensis.

	M. veliziana	M. sororum	M. guatemalensis
Twig vestiture	Glabrescent to glabrous	Densely velutinous	Glabrescent to glabrous
Petiole vestiture	Glabrescent to glabrous	Fulvo-pubescent	Glabrescent to glabrous
Leaf size (cm)	(12.0–)14.0–22.6 × (4.9–)7.1–9.4	6.0–15.0 × 3.0–9.5	12.0–16.0 × 8.0–11.0
Leaf l:w ratio	1.9–3.0:1	1.6–2.0:1	1.7–2.1:1
Leaf shape	Elliptical, narrowly elliptic to obovate Elliptical-ovate, obovate to (-lanceolate) oblong		Broadly ovate-elliptic to obovate to suborbicular
Abaxial vestiture	Glabrescent	Densely fulvo-pubescent	Scattered brown-pubescent
leaf ápex	Acuminate to cuspidate (–acute)	Obtuse to subacute	Acute, acuminate to cuspidate
Leaf base	Attenuate	Obtuse to round	Obtuse
Flower size (cm)	10.5–13.0	14.0–15.0	14.0–15.0
Petal size (cm)	5.1–5.9 × 2.1–3.2	5.5–7.0 × 2.0–4.5	6.5–7.0 × 2.8–3.0
Stamen number	103–111	87-102	92–98
Fruit size (cm)	(6.8–)7.6–8.8 × (2.4–) 2.9–3.5	4.5–6.0 × 1.8–2.4	4.8–5.2 × 1.9–2.1
Fruit vestiture	Fulvo-velutinous	Fulvo-velutinous	Glabrescent
Carpel number	47–55(–58)	32–45	22–25