Magnolia lacandonica A.Vázquez, Pérez-Farr. & Mart., 2013

Vázquez-García, J. Antonio, Pérez-Farrera, Miguel Ángel, Camilo, Ruben Martínez-, Muñiz-Castro, Miguel Ángel & Martínez-Meléndez, Nayely, 2013, Magnolia lacandonica (subsection Talauma, Magnoliaceae), a new rainforest species from Chiapas, Mexico, Phytotaxa 79 (1), pp. 30-36 : 31-34

Magnolia lacandonica A.Vázquez, Pérez-Farr. & Mart. -Camilo, sp. nov. ( Fig. 1 )

Magnolia lacandonica is similar to M. mexicana in terms of shape of fruits and leaves, but it differs from the later in having a larger number of carpels 70–80 vs 38–40 and a larger number of stamens 198–248 vs ca. 120, carpels not humped vs humped, petals entirely white vs tinged with purple. In terms of the number of carpels and stamens, M. lacandonica is similar to M. inbioana A.Vázquez (2012: 106) , but the latter has long beaked carpels and larger obovate, attenuate leaves.

Type:— MEXICO. Chiapas: Municipality Marqués de Comillas , Boca Chajul, 0.4 km al NO de la casa del Sr. Manuel Lombera, selva alta perennifolia, 150 m elevation, 16°7'18.37"N, 90°55'32.44"W, 8 May 2012 (fl. bud & fl.), Vázquez-García, Martínez-Camilo, Lombera, Torres-Santos, Santos-Flores & Vázquez-Godinez 9341 (holotype IBUG!, isotypes HEM!, MEXU!) .

Trees 28–35 m in height; 0.7 m dbh; twigs 8.70–1.30 × 0.75–1.50 cm, yellowish pubescent; petioles 6.0–7.5 × 0.3–0.4 cm, adaxially flat, yellowish pubescent. Leaves 18–22.5 × 7.0–11.0 cm, elliptic to broadly elliptic; leaf blades glabrous, with 11 secondary veins. Flowers white; hypsophylls 2, the outer one (spathaceous bract) retaining a reduced leaf blade, the inner one without any remnant leaf blade; sepals 3.4–5.8 × 3.7–5.0 cm, broadly obovate to subrotund, concave, creamy white, thicker than petals; petals 6, outer petals 6.0–6.2 x 2.7–3.2 cm, oblong-obovate, creamy white, concave; inner ones 4.8–5.8 × 2.5–3.3 cm, oblong obovate with acute apex, adaxially with sticky nectar. Stamens 198–248, 12.0 × 2.0– 2.5 mm, creamy white. Styles 3 x 1 mm. Fruits 11.5 × 9.5 cm, 11.0–15.0 cm in diameter during dehiscence, ovoid, with sunken stylar marks before maturity, yellowish-green, puberulous. Carpels 61–70, not humped, dorsally slightly verrucose, usually splitting half way of their length, few remain attached forming groups of two or three carpels after dehiscence; fruit axis 3.6–6.6 cm, ellipsoid to oblongoid, acute at the apex; seeds 1.0– 1.2 cm, subrotund, with a smooth reddish sarcotesta, black.

Distribution and ecology:— Magnolia lacandonica is endemic to the Usumacinta-Lacandonian region of Chiapas in tropical rain forest in the Lacantún and Tulijá basins. It should be looked for in southeastern Tabasco, Mexico, and in the Guatemalan portions of the Usumacinta river basin. No seedlings or saplings were observed, and there was heavy predation on flower buds and immature fruits by squirrels and/or howler monkeys. Cyclocephala sp. (a beetle) chews on flower buds and eats stamens. Magnolia lacandonica is locally rare throughout the Lacandonian rain forest.

Eponymy, ethnobotany and conservation:— It is named after the Lacandonian region , where is locally known as “tajchak” (Lacandón), “jolmashté” (Tzeltal), “anonillo”, “canelo” o “magnolia” (Spanish). Scent of the flowers resembles the smell of guanábana (fruits of Annona muricata L.). The wood of this tree is highly valued by local people, and outside protected areas its occurrence has been drastically reduced due to conversion of rainforest to agriculture and pasturelands. There was a single adult tree at the type locality and two adult trees at the Misolhá waterfall, both under protection. Several trees are protected at the Chajul Tropical Biological Station ( UNAM), Montes Azules Biosphere Reserve .

Key to species of Magnolia in Chiapas ( M. inbioana , from Costa Rica, added).

Petioles with long stipular scar; schistosyncarp with circumcissile dehiscence (Section Talauma , subsection Talauma ): Carpels 89–92, falling in large multi-carpelar irregular masses; stamens 175–179 ............................. M. sp. nov. ined. Carpels 61–70, usually falling separately, occasionally the basal ones aggregated (2–4); stamens 194–248, Leaf blades 18.0– 22.5 cm, elliptic, usually obtuse at the base, apex of dorsal wall of carpels apiculate at most .................. ............................................................................................................................................................... M. lacandonica Leaf blades 29.0–42.0 cm, oblong obovate and cuneate-attenuate basally, apex of dorsal wall of carpels prominently beaked ......................................................................................................................................................... M. inbioana Petioles with stipular scar absent or not evident; polyfollicle with dorsal dehiscence (Section Magnolia ):

Mature polyfollicles densely pubescent, mostly 7–12 (15) × 3–5 (5.3) cm in diam.

Leaves cuneate and narrowly obovate, shortly and abruptly acuminate; carpels 42–57; stamens 95–97........ M. mayae Leaves broadly obovate to ovate, abaxially with shortly appressed pubescence; carpels 85–99 (–100), stamens 220–240 .......................................................................................................................................................... M. sharpii Mature pollyfollicles glabrous, 3–6 (–7) cm long, 2–3.7 (4.4) cm in diam.

Stamens 60–72, petals gradually attenuate ............................................................................................ M. aff. poasana Stamens (100–)128–131(145), petals abruptly attenuate .................................................................... M. aff. yoroconte

Additional specimens examined:— MEXICO. Chiapas: Municipality Salto de Agua, cerca de cabañas de Misolhá , 255 m elevation, 17°23'31"N, 91°59'59"W, 8 May 2012 (fl. bud & fl.), Vázquez-García & Martínez- Camilo 9342a, 9342b ( HEM, IBUG) ; a 50 m al W (río abajo) de la cascada de Misolhá , a 15 m del río, 260 m, 17°23'28.1"N, 91°59'57.4"W, 28 December 2011 (fr.), Muñiz-Castro & Muñiz-Castro 916 ( IBUG) ; Municipality Yajalón, 500 m, Río Pulpitillo , 20 October 1982 (fr.), Shilon-Ton 4854 ( MEXU, MO) ; Municipality Chilón, San Jerónimo Tulijá , 1–15 June 1968 (immature fr.), Chavelas-P. et al 3074 ( MEXU) ; along road to Bachajon , 6–8 km N of Ocosingo, 900 m, 9 November 1971 (fr.), Breedlove & Smith 22188 ( MEXU, MO) ; Municipality Pantheló , 3 km al E del centro de Pantheló, 17°00'48”N, 92°30'54”W, 1200 m, 1 October 1994 (sterile), Schmid 27 ( CH) ; Municipality Ocosingo, Lacanjá-Chansayab, vereda de Pancho López , 115 m, 13 February 1995, Paniagua 447 ( MEXU) ; Arroyo Nuevo Tila, camino Lacanjá, 6.4 km al S de Nuevo Guerrero , 16°55'47”N, 91°16'14”W, 380 m, 27 May 2002 (fl. bud), Aguilar-M. et al. 1141 ( MEXU, MO) ; Alrededor del poblado de Bonfil , 16°48'N 91°18'W, 520 m, 23 November 1976 (fr), Valdivia-Q. 2309 ( MEXU, XAL) ; 7 00 m al SW del poblado Plan de Ayutla, Zona Norte, Chiapas , 16°48'01"N, 91°18' 41"W, 660 m, 26 October 1996 (fr.), López-García 72 ( CH) ; 2 km al N de San Javier , 16°46'48"N, 91°7'14"W, 28 January 2003 (fl. bud), Aguilar-M. et al. 5255 ( MEXU) ; 6–8 km north of Ocosingo, along road to Bachajón , 16°57'31"N 092°06'44"W, 900–925 m, 9 November 1971 (fr.), Breedlove & Smith 22188 ( MO) ; Crucero Corozal, sobre el camino Palenque-Boca Lacantún , 180 m, (fl. & fr.), 18 April 1985, Martinez-S. 12076 ( MEXU, MO, TEX, XAL) ; 7.5 km al SO de Bonampak , 16°39'51"N, 91°0'59”W, 29 November 2002 (fr.), Alvarez et al. 2752 ( MEXU) ; Municipality La Independencia, ridge, 45–50 km E of Lagos de Montebello National Park on road to Ixcán from Santa Elena, 16°07'04”N, 91°17'29”W, 760 m, 10 February 1982 (fr.), Breedlove 58475 ( MO) ; Municipality Benemérito de Las Américas, 8 km al S de Benemérito de Las Américas, camino a Flor de Cacao, en Zona Marqués de Comillas , 16°30'36"N 090°39'00"W, 8 April 1985 (fr.), Martínez S. 11619 ( MO, TEX) ; Municipality Marqués de Comillas, Estación Chajul , selva alta perennifolia, 150 m, 22 July 1992 (fl. & fr.), Martínez S., Ramos, Lombera & Guerrero 25090 ( MEXU) ; 1 km abajo de Arroyo Miranda, en los alrededores de Chajul, selva Lacandona , 14, February 1985 (fr.), Castillo- Campos et al. 3833 ( XAL) ; Boca Chajul , 1 km al SO del poblado, 16°07' N, 90°55' W, 300 m, 21 April 1992 (fl. bud & fl.), Domínguez-Vázquez 384 ( CH, MEXU, XAL) , Boca Chajul , 0.4 km al NO de la casa del Sr. Manuel Lombera, selva alta perennifolia, 150 m elevation, 16°7'18.37"N, 90°55'32.44"W, 30 Ago 2012 (fr), Martínez-Camilo 1416 ( HEM, IBUG, MEXU, MO, BIGU, XAL) .

Figures

FIGURE 1. Magnolia lacandonica. A. Spathaceous bract topped with a reduced leaf blade (left) and flower bud without spathaceous bract (right). B. Flower before fully opened. C. Gynoecium with and without stamens and showing styles. D. Carpels, single and aggregated in a small group. E. Mature fruit with inconspicuous and flat apex of carpels. F. Fruit during dehiscence, with carpels falling singly. Photographs: A–D from Vázquez-García et al. 9341 (by J. Antonio Vázquez-García); E and F, from Martínez-Camilo 1416 (by Ruben Martínez Camilo).