Magnolia yajlachhi A.Vázquez & Domínguez-Yescas, 2019

Domínguez-Yescas, Reyna & Vázquez-García, J. Antonio, 2019, Flower of the heart, Magnolia yajlachhi (subsect. Talauma, Magnoliaceae), a new species of ceremonial, medicinal, conservation and nurse tree relevance in the Zapotec culture, Sierra Norte de Oaxaca, Mexico, Phytotaxa 393 (1), pp. 21-34 : 28-32

Magnolia yajlachhi A.Vázquez & Domínguez-Yescas , sp. nov. ( Figs. 2–7 , 8 A–C )

Type:— MEXICO. Oaxaca: Mpio. San Juan Juquila Vijanos, Lachi-Luguiaj or Llano de Piedra, rare in coffee plantations that used to be cloud forest habitat in secondary Liquidambar - Pinus forest, property of Procoro Pascual, 17°21’10.2”N, 96°18’39.30”W, 1269 m, 2 Sep 2018 (fr.), Pascual Domínguez 1 (holotype: IBUG!; isotypes: CORU!, ENCB!, HUAP!, MEXU!, OAX!, SERO!, XAL!).

Magnolia yajlachhi shares with M. lacandonica the mature subglobose fruit and entirely white petals, but differs from the latter in having carpels less numerous (36–41 vs. 61–80) and marked vs. inconspicuously marked; stamens less numerous (166–175 vs. 198–248), leaf-veins per side more numerous (13–14 vs. 10–11); and seeds orange vs. scarlet. Magnolia yajlachhi shares with M. zoquepopolucae the subglobose fruit but differs from the latter in having carpels less numerous (36–41 vs. 46–56); stamens less numerous (166–175 vs. 200), petals entirely white vs. purplish in the apical portion (¾); lateral leaf-veins per side more numerous (13–14 vs. 10–11); and seeds orange vs. scarlet. Magnolia yajlachhi shares with M. mexicana a similar number of carpels and stamens but it differs from the latter in having shorter petals (7.5–7.7 vs. 9.0–10.0 cm) and entirely white vs. adaxially purplish in the apical portion (¾); fruits smaller (5.4–10.0 vs. 10.0–15.0 cm) and widely ovoid-depressed to subglobose vs. widely ellipsoid; leaf-veins per side more numerous (13–14 vs. 10–12); and seeds orange vs. scarlet ( Table 1, Fig. 8 ).

Evergreen trees, 15–20 m, 0.2–0.4 m diameter at breast height; bark grey, smooth; sapwood white; twig internodes 1.5–2.2 × 0.6–0.9 cm spotted with whitish lenticels, glabrous, dark brown; petioles 4.0 × 7.0 × 0.2–0.4 cm, adaxially flat with cracks on the petiolar scar, abaxially convex with longitudinal wrinkles, thickened and darkened at the base, finely verrucose, glabrous; stipules, stipular scar as long as the petiole; leaf blades 12.3–20.2 × 6–9.1 cm, elliptic, obtuse-subobtuse or rarely acute at the base, not evidently decurrent on the petiole, obtuse-subobtuse or rarely acute at the apex, margin undulate, with 13–14 secondary veins per side, glabrous or glabrescent; flowers white; pedunculate, spathaceous bract 1, 4.5–6.8 × 3.8–6.5 cm, pubescent, a single structure opens to the middle with 2–3 peduncular scars; sepals 3, 7.5–7.7 × 5.5–5.6 cm, cochleate, tablet-like when dried; petals 6, in two whorls; outer petals 7.5–7.7 × 5.5–5.6 cm, obovate; inner petals 5.5–7.0 × 1.9–4.2 cm, 1.7–2.0 cm wide at the base, obovate; stamens 166–175, yellow stamens with base and tip of dark brown, 1.6 × 0.3 cm, the connective obtuse to rounded; gynoecium ovoid 3.6–4 × 2.6–2.8 cm, with 36–41 carpels; styles tongue-like, 1.1 cm long, white, discrete; fruit broadly ovoid, depressed, to subglobose, 5.4–9.0 × 4.6–10.0 cm, the fruit axis 8.1–9.0 × 3.0 cm, narrowly lanceolate, acute at the apex, cuneate at the base, the cells 1.5–2.3 × 0.7–1.0 cm, 0.5–0.7 cm deep; carpels striate at the base, dorsally rugose, with an arched but non-humped dorsal wall, occasionally with an ascending apex; seeds 1–2 per carpel, 0.9 × 1.3 cm, sub-orbicular, flattened, seeds paired, some appearing prismatic with a flat side, with a bright orange sarcotesta.

Distribution and ecology:— Endemic, so far, to the Sierra Norte de Oaxaca ( Fig. 1), known from the River Cajonos, a tributary in the upper Papaloapan watershed (the Cajonos River joins the Manso River, and both form the Tesechoacán River before reaching Tlacotalpan Veracruz, where the Tesechoacán River joins the Papaloapan River), which flows into the Gulf of Mexico, inhabiting an ecotone between tropical and cloud-forest elements, often as a nurse tree in coffee plantations that used to be cloud forest habitat in the Sierra Norte of Oaxaca. On shallow, sandy loam soils, 1269–1520 m, 1200–2000 mm of mean annual rainfall, with Brunellia mexicana Standley (1927: 166 ; Brunelliaceae ), Hedyosmum mexicanum Cordemoy (1863: 307 ; Chloranthaceae ), Mikania pyramidata Donnell Smith (1888: 188; Asteraceae ), Morus celtidifolia Kunth (1817: 33 ; Moraceae ), Pinus chiapensis ( Martínez 1940: 81; Pinaceae ) Andresen (1964: 417), Liquidambar styraciflua Linnaeus (1753: 999 ; Altingiaceae ), Trema micrantha (Linnaeus 1759: 937; Cannabaceae ) Blume (1856: 58) and Vismia camparaguey Sprague & Riley (1924: 13 ; Hypericaceae ). Trees have been planted at several houses in San Juan Juquila Vijanos. Flowering occurs throughout the year, with a peak in spring, the female phase starting about at noon, whereas the male phase occurs early the next day. The flowers are visited by ants and beetles of the genus Cyclocephala Latr. in Dejean (1821: 57; Dynastinae) ( Figs. 6 A–C ). Isolated trees outside their natural habitat produce clean, white flowers since they are not visited by Cyclocephala beetles, whereas those growing naturally have plenty of this beetle destroying petals and stamens. Fruiting throughout the year, many fruits fall without producing seeds.

Eponymy and ethnobotany:— The specific epithet “yajlachhi ” derives from its common name: “yajlachhi ” (Pascual Domínguez 01), meaning “flower of the heart” in Zapotec of San Juan Juquila Vijanos, pers. comm. by Bernardo Domínguez-Yescas ( Fig. 3 A–B ), perhaps related to the heart shape of flower buds and fruits. The Zapotec culture call themselves Ben`Zaa, meaning “the cloud people”. They have endured over 2.5 millennia and overcome colonization by Aztecs and Spaniards and impacts of modern globalization. Currently one million Zapotecans continue to live their culture; Zapotec is considered a macrolanguage with nearly 62 variants and includes an ancient writing system ( Urcid 2005). Additional common names or variants for this species include: yë lhachhi and yödzö Gua in Zapotec of San Juan Yatzona (Leoncio Jiménez Hernández), yiaj lhachhi in Zapotec of San Juan Yaee (Gisella Judith Hernández Pérez). In the social network in the group “Fotografías de la Sierra Juárez Oaxaca” this species it is also recognized in Zapotec as: yëo la’chhi (Eduardo Vargas), guij lachi (Alvaro Chávez Flores), yaj lachhhe (Ms Mariscal), iulatghi (Jonas Gutiérrez), yaj lache (Armando Méndez), yaj lachhi (Mey Pérez), yaj laxhe´e (Mell Luna), yuzun buluzzu (Angel Junior Cabrera), guij lachi (Álvaro Chávez Flores) and yio lashh (Aurelio Ciprés).

Magnolia yajlachhi has traditional ceremonial use for church decoration during Easter holidays including the Holy Friday procession. Harvesting of the heart-shaped flower buds is by a group of young volunteer men, who collect nearly a thousand flowers buds and transport them well protected by their leaves, since they are fragile and may immediately become discolored if improperly manipulated. A second group of experienced men are designated to build and decorate the andas (floats; Fig. 7 C–D, F ), and nearly 40% of flower buds are used to decorate four cylindrical wooden columns nearly 2 m high, with nearly 80 flower buds nicely arranged and packed together with few leaves each. Church decoration during Easter holidays involves a third designated group led by the sacristan, and ca. 15% of flower buds are reserved for this activity. At the Yatzona church, these men carefully prune the branches and unnecessary leaves to arrange a dozen flower vases filled each with 10 to 12 heart-shaped white flower buds and their dark green leaves ( Figs. 7 A–B ). These flower vases are then placed on the altar together with flower vases of magenta-flowered bromeliads ( Tillandsia sp. ). The altar eventually receives the impressive decorated columnar andas. In the Good Friday procession, women mostly dressed white lead the procession, carrying the little virgin sculpture while men mostly dressed in blue trousers form a second line carrying the impressive, heavy andas, including a large sculpture of Jesus. Behind these, lines of mostly boys and men carry one or two beautiful flower buds of M. yajlachhi , as if they are holding in their hands a heart to sacrifice to God as a sign of recognition or obedience. Approximately 25% of the heart-shaped flower buds are used for this activity. A similar ceremonial use is reported from Puebla (San Andrés Chalchicomula) with flowers obtained from La Magdalena, Veracruz ( Sánchez-Cuahua 2016); however, they use a different species, M. mexicana (yoloxóchitl in Náhuatl, “flower of the heart”), for a different ceremony, Sunday of the Santísimo Sacramento) at a different season (summer), usually the third Sunday of June when M. mexicana is flowering ( Sánchez-Cuahua 2016). The species is occasionally used in Juquila Vijanos as an offering in the tombs of the cemetery, the only native species among many exotic ones: goldenrods, lilies, geranium and hydrangea ( Fig. 7 E ), as an offering and sign of gratitude and farewell to deceased beloved ones.

Magnolia yajlachhi is frequently used as a medicinal plant in the Zapotec culture. An infusion of petals is said to be good for strengthening the heart (Bernardo Domínguez Yescas ( Fig. 7 A–B ). Leaves are prepared as a fasting infusion to tone the blood and clarify the eyes (Almicar Barcas). In Yaee, Oaxaca, the strongly aromatic flowers are used to treat asthma (Gisella Judith Hernández Pérez). Similarly, several medicinal uses are reported for M. mexicana from Zongolica, Veracruz ( Sánchez-Cuahua 2016).

Magnolia yajlachhi is also used as a nurse tree in coffee plantations at San Juan Juquila Vijanos ( Fig. 6 F ) and San Juan Yatzona, a traditional management practice also noted for M. ofeliae in Talpa de Allende, Jalisco ( Vázquez-García et al. 2013b), M. macrocarpa in Coatlán, Oaxaca (Ciro Pérez, pers. comm.), M. mexicana in Zongolica, Veracruz ( Sánchez-Cuahua 2016) and Magnolia cubensis Urban (1899: 307) in Cuba. This management practice requires evaluation of its effectiveness in terms of conservation of genetic diversity in Magnolia because it may add value for coffee producers through this new concept (“ Magnolia -nursed coffee”) of conserving biodiversity by using endangered or threatened species of Magnolia as nurse trees in their coffee plantations.

Conservation status:— These trees are to some extent protected by people due to their ceremonial value in church decoration and use in medicinal and as nurse trees in coffee plantations. Several plants grown from seeds near the Church of San Juan Juquila Vijanos failed to survive, possibly because of water stress and insufficient nutrients because they were located on top of a hill, with greater exposure to sunlight, frequent wind and soil leaching. In Yatzona, Oaxaca, the trees are managed inside the coffee plantations or along roadsides, and when the people of the village locate a Magnolia seedling, they clean the herbs around them so that they grow better with less competition because they consider these trees as an inheritance from their ancestors. Major threats to this plant include flower harvesting for ceremonial and medicinal use, deforestation for agricultural and urban expansion and climate change. The category assigned to this species was critically endangered (CR). Conservation status of Magnolia yajlachhi was evaluated considering the following criteria [B1b (i, ii) and B2b (i, ii)] of the IUCN Red List Categories and Criteria ( IUCN 2012).

Additional Specimens examined: — MEXICO: Oaxaca. Mpio. Municipio San Juan Juquila Vijanos, backyard of the Domínguez-Yescas home, 17°21’15.41”N, 96°18’13.47”W, 1520 m, 10 Jul 2010 (fl), Domínguez-Yescas 78 (IBUG) ; same as previous location 30 Jul 2013 (fl), Domínguez-Yescas 79 (IBUG); same as previous location, 15 Apr 2014 (fl), Vázquez García 10112 (IBUG); Llano de Piedra (Lachi-Luguiaj in Zapotec), property of Procoro Pascual , 17°21’10.2”N, 96°18’39.30”W, 1269 m, 01 Ago 2013 (fl), Domínguez-Yescas 80 (IBUG) ; same as previous location, 27 Nov 2013 (fr), Domínguez-Yescas 81 (IBUG); same as previous location, 23 Sep 2018 (fr), Pascual Domínguez 2 (IBUG, CIDIR); Mpio. Tanetze de Zaragoza, rare, planted on the right side of the Catholic church in the center of the town, 5 km from the Municipal Agency of San Isidro Reforma , coming from the community San Juan Juquila Vijanos , 17°22’29.14”N, 96°18’8.47”W, 1332 m. 15 Sep 2018 (fr.), Pérez Santiago 1, (IBUG, CIDIR, MEXU) ; Municipal Agency Santa María Zoogochi, cultivated in front of the municipal agency, attached to the basketball court, property of Taurino Salvador Chávez , 17°25’52.53”N, 96°20’17.03”W, 1142 m. 19 Sep 2018 (fl), Bautista Pérez 1 (IBUG, CIDIR, MEXU) ; Mpio. San Juan Yaee, planted 50 m before arriving at the Catholic Church , 17°25’45.83”N, 96°16’58.87”W, 1436 m. 6 Oct 2018 (fr), Hernández Pérez 1 (IBUG, CIDIR, MEXU) ; Mpio. San Juan Yatzona , 17°24’6.87”N, 96°10’3.37”W, 1280 m. 16 Sep 2018 (fr), Rodríguez Pérez 1 (IBUG, CIDIR, MEXU) .

Figures

FIGURE 2. Magnolia yajlachhi. A. Flowering branch. B. Flower with reflexed sepals. C. Receptive gynoecium (female phase), still retaining the stamens. D. Leaf venation. E. Flower bud without spathaceous bract. F. Fruit axis. G. Fruit. (By Edgar Esau Vázquez Verdejo).

FIGURE 3. Magnolia yajlachhi at San Juan Juquila Vijanos, Oaxaca.A–B. Bernardo Domínguez Yescas and his wife, Ma. Luisa Pascual- Yescas, the family that transplanted and cared for seedlings for over a decade, until the trees flowered and turned out to be a new species. C. First documented (2010) open flower at male phase for this species. D. Flower bud flower of the heart, ready to be harvested for decoration, each tree producing up to 200 flower buds. E. Female phase (1:30 pm), with ca. perpendicular sepals, partially opened for beetle entrance, closing latter at night. F. Male phase (8:01 am) fully open flower, after pollen shedding (Photographs: A, D–F by J.A. Vázquez-García; B–C by R. Domínguez-Yescas).

FIGURE 4. Magnolia yajlachhi. A. Leaves from a young shoot, found under shade. B. Leave exposed to direct sunlight. C. Spathaceous bract protecting the young flower bud. D. Heart shaped flower bud fully grown. E. Flowers at female phase, with sepals at an angle of ca. 30 degrees from the axis, barely opening for beetle entrance. F. Flower at female phase with perpendicular sepals, starting to close, usually with insects inside. G. Flower with reflexed sepals at an angle of ca. 80 degrees. H. Receptive gynoecium, female phase, with stamens. I. Receptive gynoecium (female phase, with stamens removed. J. Stamens. (Photographs:A, E and H–I by J.A. Vázquez-García; B–D, F–G and J by R. Domínguez-Yescas; G and H).

FIGURE 5. Magnolia yajlachhi. A. Sterile fruits of a cultivated tree at Juquila Vijanos, Oaxaca, B–D. Fruit, and fruit axis with seeds at Llano de Piedra, E–F. Flowers of a tree within a coffee plantation in Llano de Piedra, Juquila, showing rusty spots due to visiting beetles (Photographs:A–F by R. Domínguez-Yescas).

FIGURE 6. Magnolia yajlachhi at Llano de Piedra.A–B Two kinds of visiting beetles. C–D, F–H. Piercing the flower by beetles (possibly Cyclocephala). E. Two-stem tree (Photographs:A–H by R. Domínguez-Yescas).

FIGURE 7. A. Flower bud bouquet. B. Procession of Good Friday in San Juan Yatzona, using flower buds. C. Sculpture of Jesus on a donkey decorated with flower buds. D. Men of San Juan Yatzona decorating with Magnolia flower buds. E. Altar at San Juan Yatzona´s church decorated with flower buds and bromeliads. F. Tomb in cemetery adorned with Magnolia flower buds (Photographs: A by J. Bautista-Vargas, B by D. Sánchez-Luna, C–D and E by S. A. Hernández-Merlín, F by J. A. Vázquez-García).

FIGURE 8. Magnolia yajlachhi (left side).A. Open flower. C. Mature fruit before dehiscence. E. Fruit axis with seeds, after circumscissile dehiscence.Magnolia mexicana (right side) B. Open flower. D. Mature Fruit before dehiscence. F.Fruit axis with seeds, after circumscissile dehiscence. (Photographs: A, C and E by R. Domínguez Yescas; B, D and F by R. Sánchez Cuahua).