Floristics and taxonomy

 

Magnolia mayae (Magnoliaceae), a new species from Chiapas, Mexico

 

Magnolia mayae (Magnoliaceae), una especie nueva de Chiapas, México

 

J. Antonio Vázquez-García^1,3, Miguel Ángel Pérez-Farrera², Nayely Martínez-Meléndez², Gregorio Nieves-Hernández¹ and Miguel Ángel Muñiz-Castro¹

 

¹ Herbario IBUG, Instituto de Botánica, Departamento de Botánica y Zoología, Universidad de Guadalajara, Guadalajara, Mexico.

² Herbario Eizi Matuda, Facultad de Ciencias Biológicas, Universidad de Ciencias y Artes de Chiapas, Tuxtla Gutiérrez, Chiapas, Mexico.

³ Corresponding author: jvazquez@cucba.udg.mx.

 

Recibido: 25 de febrero de 2012
Aceptado: 20 de abril de 2012

 

Abstract

A new species of Magnolia from Chiapas, Mexico is described and illustrated. A table of morphological characters contrasting species of Magnolia Sect. Magnolia in Chiapas is provided. Magnolia mayae is similar to M. grandiflora, but it differs from the latter in having longer leaves, less coriaceous and abaxially glabrous vs abaxially densely ferrugineous pubescent; smaller flowers with less than half of the stamens, and a smaller number of carpels.

Key words: Magnolia aff. yoroconte, Magnoliaceae, Magnolia mayae, Magnolia sharpii, section Magnolia, section Theorhodon.

 

Resumen

Se describe e ilustra una especie nueva de Magnolia de Chiapas, México. Se proporciona un cuadro de caracteres morfológicos que contrasta las especies de Magnolia Sect. Magnolia de Chiapas. Magnolia mayae es similar a M. grandiflora, pero difiere de ésta última en tener hojas más largas, menos coriáceas y abaxialmente glabras vs abaxialmente densamente ferrugíneo pubescentes; flores más pequeñas con menos de la mitad de estambres y con menor número de carpelos.

Palabras clave: Magnolia aff. yoroconte, Magnoliaceae, M. grandiflora, Magnolia sharpii, sección Magnolia, sección Theorhodon.

 

Neotropical Magnoliaceae are quite diverse and still much too poorly understood (Vázquez-García, 1994). A circumscription of the genus Magnolia L. is still controversial; Figlar and Noteboom (2004) and Figlar (2006) merge various genera, including the genus Talauma DC. within Magnolia. However, recent nuclear molecular evidence shows that Neotropical Talauma forms a basal monophyletic clade, sister to the Asiatic counterpart, Aromadendron (Nie et al., 2008), and both are sister to a large clade where Magnolia and other genera are grouped. Talauma and Aromadendron, are tropical disjuncts that have occurred prior to the disjunctions of temperate taxa (Azuma et al., 2001). Molecular evidence (RFLP, ndhF,) shows that species of Magnolia, Sect. Theorhodon Spach., except for those Caribbean species of Sect. Splendentes sensu Vázquez-García (1994), form a monophyletic clade together with Magnolia virginiana of Sect. Magnolia Dandy (Qiu et al., 1995; Kim et al., 2001). Thus, New World Sect. Magnolia now includes 16 species, M. virginiana from eastern U.S.A. and Cuba, M. grandiflora from eastern U.S.A., nine species from Mexico and five species from Central America (Vázquez-García, 1994). Only two species are native to Chiapas, M. sharpii Miranda and M. aff. yoroconte Dandy (Vázquez-García, 1994). Here, we propose Magnolia mayae, as a new species and member of Sect. Magnolia.

Magnolia mayae A. Vázquez & Pérez-Farrera sp nov. (Figure 1). Arbores 15 a 25 m altae, trunci usque 35 a 50 cm diam. Folia anguste obovata acuminata, lamina 33-43 longa, 8.5-13.5 cm lata, glabra; stipulae ignoti. Flores 12-18 cm diam; fructus ellipsoidei, 8-10 cm longi; 4-5 cm lati. Folliculi 42-57, dense fulvo-velutini, uncinato-rostrati. Semina 8.6 a 9 mm longi, 8.2 a 8.5 mm lati.

TYPE: México, Chiapas, Mpio: Trinitaria, Carretera Tziscao-Las Nubes, 16° 06' 33.7" N, 91° 33' 34.2" W, 1,079 m, 11/11/2008 (fruit), Nayely Martínez Meléndez 2480 (Holotype: HEM; Isotypes: MO, IBUG).

Trees 15 a 25 m height, 35-50 cm dbh; first branches 3-5 m height; outer bark pale brown, inner bark yellow to ocher after oxidation; twigs 9-10 mm thick, glabrous, lenticelate, internodes 3-11 mm long; leaves 33-43 × 8.5-13.5 cm, oblong-obovate, cuneate at the base, abruptly and shortly acuminate at the apex, thin, glabrous; secondary anastomosate veins 15-16, curved, inclined 46-50 degrees, abaxially more evident; stipules unknown; petioles 4.5-5.7 × 0.3-0.4 cm, slightly canaliculate to flattened, rough and darker at the abaxial base, glabrous; foliar bud ovoid acuminate 1.7 × 0.8 cm; flower buds 3.1-12.2 × 1.6-3.6 cm, ellipsoid, light green, pubescent at the tip; bracts 4, deciduous, the upper-most spathaceous; peduncles 4.3-8.5 × 0.8-1.3 cm, glabrous, striate, lenticelate; open flower 7.2-10 × (8.8-) 12-18 cm, white; sepals 3, 7-8 × 4.6-4.9 cm, oblong obovate, concave, abaxially light greenish; petals of external cycle 3, 5.5-9.6 × 2.8-5.5 cm, cuneate obovate; petals of internal cycle 3, 5-8.3 × 2.2-4.5 cm, cuneate obovate, widest at the upper fourth; stamens 95 (staminal scars semicircular); styles 1-2 × 1 mm; polyfollicles 8-10 × 4-5 cm, oblongoid to ovoid; follicles 42-57, 9-13 × 4-8 mm, oblongoid, apiculate, elongated up to 8 mm long, densely felty yellowish (hairs 2 mm long); seeds 8.6-9 × 8.2-8.5 mm (Figure 1).

Distribution and ecology. This species is present in lower montane rainforest, at 760-1,200 m elevation, with a mean annual rainfall of 3,200 mm, at temperate moist climate, and clay soils. Magnolia mayae is known only from the state of Chiapas, Mexico, at the municipality of Yajalón, growing together with Clethra nicaraguensis C.W.Ham., Licaria capitata (Schltdl. & Cham.) Kosterm., Ocotea leucoxylon (Sw.) Laness., Saurauia yasicae Loes., and Zanthoxylum foliolosum Donn.Sm. and sharing habitat at the municipality of Trinitaria with Alchornea latifolia Sw., Annona reticulata L., Arachnothryx buddleioides (Benth.) Planch., Astrocaryum mexicanum Liebm. ex Mart., Belotia mexicana (DC.) K.Schum., Chamaedorea elatior Mart., C. ernesti-au-gusti H.Wendl., Clusia guatemalensis Hemsl., Costus sp., Heliconia sp., Inga vera Willd., Miconia glaberrima (Schltdl.) Naudin, Piper spp., and Podocarpus matudae Lundell.

Phenology. Flowering during late spring and fruiting from September to December.

Etymology. The specific epithet for this new taxon is from "maya", the Spanish name of the Mayan culture that dominated the region where it occurs.

Conservation. Magnolia mayae is only known from three locations, in Chiapas, Mexico, but may occur in Guatemala as well. At municipality Trinitaria only 11 individuals were observed between the highway and the forest slope, along a 400 m long transect, close to a coffee plantation, only two of those trees were mature (ca. 13 m tall). This extremely rare species should be given a protected status immediately in the Mexican endangered species act (Norma Oficial Mexicana), most likely, within the critically endangered species category.

Magnolia mayae is only distantly related to M. grandiflora L. (native to southeastern U.S.A.), it has somewhat similar large ellipsoid fruits, however the former has less carpels (42-57) vs 75-90 in M. grandiflora; leaves of M. mayae are narrowly obovate, shortly acuminate, thin and glabrous, while in M. grandiflora are oblanceolate to elliptic and rarely obovate, obtuse at the apex, coriaceous and abaxially ferrugineous pubescent; flowers of M. mayae are smaller, 12-18 cm vs 17.5-20 (-30), perianth with 3 sepals and 6 petals vs 9-15 tepals, with less stamens, 95 vs > 250 (Table 1). Magnolia mayae has yellowish pubescent, fruits similar to those of M. sharpii, however, it differs from the latter in having narrower leaves, 8.5-13.5 cm vs 9-18 (-24) cm, cuneate at the base and shortly acuminate at the apex vs obtuse at the base and apex; abaxially glabrous vs abaxially densely appressed pubescent; fewer stamens 95 vs 220-240; and fewer carpels 45-57 vs 85-99 (-100). Magnolia mayae has glabrous leaves as those of M. aff. yoroconte, however, it differs from the latter in having longer leaves 33-43 cm vs (7-)9-19(-23) cm; fewers tamens 95 vs 100-145; longer fruits 8-10 cm vs 4-6 cm, with more carpels 42-57 vs (25-) 40-42, and the dorsal wall of carpels densely yellowish pubescent vs glabrous. In addition, Magnolia mayae differs from M. guatemalensis Donn.Sm. in having longer leaves 33-43 cm vs 7-20 (-25) cm, abaxial blades glabrous vs ferrugineous-sericeous when young, longer fruits 8-10 cm vs 3-5.7, and a larger number of follicles 42-57 vs 22-38.

Additional specimen examined. México, Chiapas, municipality of La Independencia, 45-50 km east of Lagos de Montebello National Park, on road from Ixcán to Santa Elena, 760 m, in lower montane rainforest (sterile), 22/01/1982, Breedlove 5776 (MEXU); municipality of La Trinitaria, km 23.4 Hw. from Lagos de Montebello National Park to Las Nubes, Ejido Cuauhtémoc, 16° 06' 34" N, 91° 33' 41" W, 1,094 m, in lower montane rainforest (flower), 07/05/2011, N. Martínez-Meléndez 2888 (HEM, IBUG, MEXU); municipality of Yajalón, Ejido San Pedro Sotolá, Hw. from Ojo de Agua to Lucio Blanco, Rancho Ojo de Agua, 17° 12' 06.8" N, 92° 15' 44.2" W, 961 m, (flower), 13/4/2011, H. Gómez-Domínguez 3142 (HEM, IBUG); municipality of Yajalón, Sierra Anover, Hw. Ojo de Agua to Lucio Blanco, Rancho Ojo de Agua (sterile), 17° 11' 30" N, 92° 15' 44" W, 1,000-1,200 m, 10/4/2000, M.A. Pérez-Farrera 2330 (HEM).

 

Acknowledgements

We thank to Gladis Yareni Pérez López, Héctor Gómez Domínguez, and Manuel Martínez Melendez from Universidad de Ciencias y Artes de Chiapas, Jesús G. González Gallegos and Marcelino Vázquez García, from Universidad de Guadalajara-CUCBA. To Heraclio and Alonso, for their valuable support during our fieldtrip in the mountains of Chiapas in November and December 2009. The second and third authors give special thanks to Christopher Davidson and Sharon Christopher for their support during a visit to Yajalón, Chiapas in December 2009. To Osvaldo Zuno Delgadillo for the nice illustration.

 

Literature cited

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