Rosales, Vázquez-García & Basáñez & Acevedo-Rosas & Rosales-Martínez & Padilla-Lepe & Martínez-González & García-Ruiz & Gutierrez & Nieves-Hernández & Guzman & Shalisko & Machuca-Núñez & Hernández-López & Muñiz-Castro, 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 : 231-235

publication ID	https://doi.org/10.11646/phytotaxa.695.2.3
persistent identifier	https://treatment.plazi.org/id/0383FD6B-CE41-E61B-E1C1-F8775A8DF9E4
treatment provided by	Felipe
scientific name	Rosales
status	sp. nov.

Treatment

Quetzalcoatlia latipetala A. Vázquez, I. García View in CoL & Rosales sp. nov. ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 & 17–18 View FIGURE 17 View FIGURE 18 ).

Type:— MEXICO. Michoacán: municipality of Aguililla, at the waterfall of El Salto, 4 km north of Aguililla, Sierra de Coalcomán, 1200 m, May 1973, Alfred Lau 49 (holotype HNT!).

Diagnosis:— Quetzalcoatlia latipetala is similar to Q. pentandra , as they overlap in rosette size and share basal thickened bracts, but it differs from the latter in having shorter habit 15.0–16.0 vs. 19.0–24.0 cm, stouter vs. slender stems; leaves mostly concave, upward and abruptly attenuate vs. convex to flat, reflexed and gradually attenuated; leaves yellowish to bluish green, slightly pinkish at the margin vs. blue-glaucous to tinged with lavender; basal bracts 1.6–2.3 × 1.0– 1.2 cm long, ovoid, acute at the apex vs. 3.5 × 1.5 cm long, lenticular and obtuse at the apex; more numerous flowers per full-full-sized inflorescence 23–27 vs. 31–36; shorter pedicels 0.8–1.7 vs. 1.8–2.3 cm; wider flowers 20.0–21.0 vs. 17.9–18.0 mm; larger corolla lobes, 8.0–8.1 × 4.5–4.6 mm, distally less reddened, banded and spotted at the lower half vs. 6.9–7.0 × 1.7–1.75 mm, distally solid rusty reddish and mostly none spotted at the lower half.

Description:— Plants herbaceous, perennial, 15.0–16.0 cm tall, excluding inflorescence, erect to decumbent, ramose with lateral branches below the rosette; stems 8.4–9.5 × 0.5–0.6 cm, smooth with brown scars; leaf scars 1.2–1.4 × 0.9–1.2 mm, flat, broadly elliptic to subcircular and brown; rosettes terminal, 3.2–3.8 × 5.8–6.8 cm with 17–18 leaves. Leaves 2.1–3.1 × 1.2–1.6 cm, 2.2–2.3 mm thick at the base, obovate to broadly obovate, to broadly ellipsoid, adaxially concave, abaxially convex, yellowish to bluish green, the margins slightly pinkish; the base cuneate, the stalk-like, basal portion 3.5–3.6 mm wide, the apex obtuse to acute, apiculate with a mucro ca. 1.0–1.5 × 0.8–3.3 mm. Inflorescences up to 3, 13.0–21.3 × 16.0–24.0 cm, the fertile portion 8.0– 13 cm long, with 23–27 flowers on 3–4 secondary axes (branches), each branch spaced 2.1–2.6 cm; primary axis 2.9–3.1 mm thick at the base, 1.1–1.2 mm thick above, straight and perpendicular to the stems, brown; bracts 8–10, proximal ones 9.0–9.2 × 6.6–6.8 mm, obovate and obtuse, the basal bracts ovoid; branches 9.3–11.6 cm, simple, zigzagged or straight, brownish, with 5–8 flowers, the basal branches bearing 5–8 flowers and nearly perpendicular to primary axes, proximal pedicels spaced 2.4–3.4 mm; bracteoles 7–10, distal ones 1.7–32.1 × 1.1–1.3 mm, narrowly oblongoid acute at the apex, grayish dull green; pedicels 0.8–1.7 × 0.11–0.13 cm, distally ticker, pale brownish when dried; flower buds 4.7–4.9 × 5.4–5.6 mm, ovoid, the sepals covering ⅔ of the corolla, the calyx glaucous to grayish dull green, glabrous, the corolla yellowish. Flowers 20.0–21.0 mm in diam.; calyx fused 0.4–0.6 × 4.4–4.5 mm; calyx lobes 5, 3.7–3.9 × 1.3–1.7 mm, dull greenish, distally darker; corolla tubes 2.9–3.1 × 4.0– 4.1 mm; corolla lobes 5, 8.0–8.1 × 4.5–4.6 mm, triangular, creamy white to greenish at the base, rusty reddish at the distal third, faintly red banded or dotted; stamens 5, erect at early stage of anthesis, later reflexed; filaments 5.3–5.4 × 0.5 mm, proximally yellowish at the base, reddish at the distal ⅔; nectaries unknown; stamens 5, erect in the early stage of anthesis, later reflexed; anthers subglobose 0.8 mm in diam., yellowish to pale brown; gynoecium 8.8–9.0 × 5.1–5.5 mm, mostly yellowish the lower half, reddish the distal 5–10%, the carpels 9.1–9.2 × 2.0– 2.3 mm, keel at right angle, abaxially pinkish at the middle, reddish at the apex; styles 1.1–1.2 × 0.1–0.5 mm, dark red; stigmas 0.3–0.4 mm. Fruits 9.1–9.2 × 0.5–0.6 mm, obovoid, dark brown, the apex of carpels with a persistent beak, arched-out; seeds 0.48–0.52 × 0.24–0.36 mm, narrowly oblong, beige.

Distribution, habitat, and phenology: — Quetzalcoatlia latipetala is known only from some subpopulations at the type locality, in the waterfall of El Salto, Aguililla, Michoacán, in tropical deciduous forest, at an elevation of approximately 1200 m, growing with Mammillaria knippeliana Quehl and Mammillaria xaltianguensis var. aguilensis Repp. It flowers from early March to April, fruiting in June.

Etymology:—The specific epithet “ latipetala ” refers to its broad petals, the broadest and largest among Quetzalcoatlia .

Notes: —The species was first collected by Alfred Lau in May 1973, who thought he had discovered the first wild population of Graptopetalum pentandrum . In the late 1990’s, the species was again collected and photographed by Ignacio García, which allowed us to describe this distinctive new species, half a century after its discovery. Gametic chromosome number: n=32 ( Kimnach 1987). It has some potential as an ornamental.

Preliminary Conservation Assessment:—Following the IUCN Red List criteria B1ab(iii) ( IUCN 2022) this species was assessed as Critically Endangered (CR): The EOO is less than 100 km 2 (B1); The AOO <10 km 2 (B2); this species is only known from a single location (condition a); and we inferred a decline of quality of its habitat (condition b(iii)) through land use change, recreation and increasing water demands for irrigation. This species is being reproduced at HNT.

Additional specimens examined:— MEXICO. Michoacán: Municipality Aguililla, at the waterfall of El Salto, approx. 8.5 km north straight line of Aguililla , east side of Sierra de Coalcomám , 795 m, 20 April 1998, cultivated at Jiquilpan, I. García, 5130- Bis ( CIMI!) ; same locality, 10 April 1999, cultivated at Jiquilpan, I. García 5592 ( CIMI!) .