Quetzalcoatlia grulloensis A. Vázquez & Padilla-Lepe, 2025

Vázquez-García, J. Antonio, Basáñez, Miguel Cházaro, Acevedo-Rosas, Raúl, Rosales-Martínez, C. Santiago, Padilla-Lepe, Jesús, Martínez-González, Rosa E., García-Ruiz, Ignacio, Gutierrez, Byron Gutiérrez, Nieves-Hernández, Gregorio, Guzman, Ramón Cuevas, Shalisko, Viacheslav, Machuca-Núñez, J. Antonio, Hernández-López, Leticia & Muñiz-Castro, Miguel Á., 2025, Quetzalcoatlia (Crassulaceae), high small-scale diversification in western Mexico: a synopsis with four new species, Phytotaxa 695 (2), pp. 207-254 : 214-220

Quetzalcoatlia grulloensis A. Vázquez & Padilla-Lepe sp. nov. ( Figs. 1–3 & 5–6 ).

Type:— MEXICO. Jalisco: municipality of El Grullo, Sierra de Amula, on steep rocky slopes, on the base of trees, in tropical dry forest with Calliandra , Cephalocereus , Ficus , Inga , Lysiloma , Pachycereus , Plumeria , Pseudobombax , 3 June 2022 (fr), G. Nieves-Hernández y J. Padilla-Lepe, recorded by J. Antonio Vázquez-García 10194 (holotype IBUG!, isotype ZEA!).

Diagnosis:— Quetzalcoatlia grulloensis is similar to Q. superba in having a ramose decumbent or pendulous habit, rosette size, tuberculate stems, leaf size and oblanceolate leaves, but it differs from the latter in having longer stems 19.0–40.0 (vs. 14.0–15.0 cm) basal leaves navicular (vs. flat); leaf apex acuminate to rounded (vs. obtuse with an apical mucro 1.0– 1.5 mm long and wide); leaves greenish to pink-grayish (vs. gray-bluish to pink-violet); shorter inflorescence 8.0–29.0 cm (vs. 30.0–40.0); less numerous branches per full-size inflorescence 7–9 (vs. 12–15); less numerous flower per basal branch 3–5 (vs. 8–12); longer corolla tube 3.7–3.8 mm (vs. 2.9–3.1); and petals yellowish with red-purple spots toward the apex (vs. proximally creamy-white to yellowish green, distally red wine and inconspicuously striped); and shorter fruits 2.4–2.6 (vs. 4.75–5.25 mm).

Description:— Plants suffrutex, perennial, 30.0– 45.6 cm tall, caulescent, decumbent, pendulous; stems 19.0–40.0 × 0.9–1.4 cm, branched at 10.0–27.0 cm, smooth and tuberculous, slightly glossy brown; rosettes 3.5–5.6 × 7.5–13.5 cm, 11–26 clumped leaves. Leaves 3.5–6.5 × 1.7–2.8 cm, 6.0– 8.5 mm thick, oblong-obovate, adaxially concave, acuminate to rounded at the apex, the basal leaves navicular; glaucous greenish to pink-gray, yellowish in the sun, sometimes with a faint pinkish tinge around the edges. Inflorescences 8.0–29.0 cm, 7–9 alternate branches per full-size inflorescence, 1–2 bifurcated, longest branches 6.5–9.0 cm, with 2–8 flowers each, 11–14 flowers when bifurcated, 3–5 flowers on basal branches, 35–69 flowers per inflorescence; phyllotaxy 3; pedicels 0.5–2.0 × 0.1 cm; flower buds 1.21–1.29 × 0.75–0.88 mm. Flowers 14.0–16.0 mm in diameter; sepals 5.0 × 2.5 mm, ovate, obtuse at the base and acute at the apex; corolla tube 3.7–3.8 mm, corolla lobes 5.8–6.0 × 2.4–2.5, lanceolate, acute at the apex, yellowish, spotted with red-purple from the middle to the upper 1/3; nectaries reniform and yellow; stamens 6.0 mm long; gynoecium 6.0 mm long, carpels costate, acute at the apex, green to yellowish, whitish at the base, pistil pink to reddish, apiculate. Fruits 2.4–2.6 × 1.5–1.6 cm; seeds 0.41–0.53 × 0.17–0.2 mm.

Distribution, habitat, and phenology:—It is found in the state of Jalisco in the municipality of El Grullo, within the Sierra de Amula near the Puerta del Barro town, around the El Tigre stream. This rupicolous species hangs on basalt rock cliffs within the deciduous tropical forest above 1000–1100 m a.s.l., it is accompanied by plant species such as Calliandra caeciliae Harms. , Plumeria rubra L., Lysiloma acapulcensis (Kunth) Benth. , Ficus sp. , Pachycereus pectenaboriginum (Engelm. ex S. Watson) Britton & Rose , Pseudobombax palmeri (S. Watson) Dugand , Cephalocereus alensis (F.A.C. Weber) Britton & Rose , Agave stringens Trel. , Tillandsia capitata Griseb. , and Oncidium sp. This species flowers from May to June and bears fruit in June.

Etymology: — The species is named after the municipality El Grullo, in Jalisco, and is so far endemic to this area.

Notes:—Its glaucous green to pink-gray rosettes make it distinctive, growing easily from seeds and leaf cuttings. This species was first discovered in El Grullo, Jalisco, collected vegetative ( Hernández et al. 2409) and cultivated on October 20, 2021 by M. Sc. Leticia Hernández-López, from the University of Guadalajara. Soon after, this taxon was treated as Graptopetalum superbum (M. Kimnach) Acevedo-Rosas , ( Hernández-López & Carrillo-Reyes 2019). Some years later, Gregorio Nieves and Jesús Padilla obtained mature plants, which bloomed at Zapopan in June 2022.

Preliminary conservation assessment:— According to the IUCN Red List criterion B2 (AOO <10 km 2), and conditions ab(iii) ( IUCN 2022), the species could be considered Critically Endangered ( CR). Additionally, due to its rarity and narrow distribution (condition a), this species experiences a continuing decline observed and projected in area and quality of habitat (condition b(iii)), because of the increase in plant hunting. This species is so far endemic to the western portion of the Sierra de Amula , Jalisco, Mexico, known only from one location, the type locality, where it has been registered from a single population. The species spatial dispersion tends to be gregarious in groups from 30 to 50 individuals, and some solitary plants ; the total population size is estimated to be 300 individuals. It must be a target for conservation and research efforts. The first successful step in the recovery of this species started on June 24, 2022, through the first germination trial of about 100 seeds, and a second germination trial started in June 2023, the plants are growing fine at the University of Guadalajara´s greenhouse at Zapopan, Jalisco .

Additional specimens examined:— MEXICO. Jalisco: Municipality of El Grullo, Sierra de Amula, cultivated at Zapopan, 3 June 2022 (fl), J. Antonio Vázquez-García 10266 ( IBUG!).

Figures

FIGURE 1. Geographic distribution of species of Quetzalcoatlia. All species of Quetzalcoatlia within a radius equal to or less than 101 km.

FIGURE 2. High small-scale rosette diversity in Quetzalcoatlia, half of their actual size.A. Quetzalcoatlia trujilloi. B. Q. itzicuaroensis. C. Q. superba. D. Q. glassii. E. Q. kristenii. F. Q. rosanevadoensis. G. Q. latipetala. H. Q. grulloensis. I. Q. pentandra. J. Q. santamichelii. Photographs:A & D–E by J. Etter & M. Kristen, B–C & F by A. Vázquez-García, April 2022, G Reproduced from Kimnach (1987), H by J. Padilla-Lepe, I Reproduced from Moran (1971), J. by D. Figueroa-S.

FIGURE 3. Quetzalcoatlia. High small-scale flower diversity in western Mexico, size-proportions kept among the flowers. A. Quetzalcoatlia latipetala. B. Q. glassii. C. Q. pentandra. D. Q. itzicuaroensis. E. Q. superba. F. Q. grulloensis. G. Q. rosanevadoensis. H. Q. kristenii. I. Q. trujilloi. J. Q. santamichelii. Photographs: A by I. García Ruiz, B, D–E & G–I by J. Etter & M. Kristen, C reproduced from R. Moran (1971), F by J. Padilla-Lepe, and J by A. Vázquez-García.

FIGURE 5. Quetzalcoatlia grulloensis. A. Rosette. B. Rosette and infructescence, C. Inflorescence.D. Flower after male phase. E. Flower at anthesis. Photographs A, C–E by A. Vázquez-García (2023) and B by J. Padilla-Lepe.

FIGURE 6. Quetzalcoatlia grulloensis. A–D Habitat, tropical dry forest, Sierra de Amula, Jalisco, Mexico. Photographs by J. Padilla- Lepe, June 2022.