Quetzalcoatlia superba (Acev.-Rosas) A. Vázquez

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 : 242-246

Quetzalcoatlia superba (Acev.-Rosas) A. Vázquez & Rosales, Boletín Nakari 34(2): 39 (2023) ( Figs. 1–3 & 22 ).

= Graptopetalum pentandrum subsp. superbum Kimnach, Cact. Succ. J. (Los Ángeles) 59: 142 (1987).

≡ Graptopetalum superbum (Kimnach) Acev.-Rosas, Novon 13(4): 380 (2003).

Type:— Cultivated. MEXICO. Jalisco: municipality La Barca, near Guadalajara, the native locality unknown, Aviña s.n., HNT acc. no. 49307 (holotype HNT!, sheet #6392; isotypes BH!, MEXU!, US) .

Description:— Plants suffrutex, ramose, perennial, 40.0–80.0 cm, branching basally, entirely glabrous; stems 1.0– 1.2 cm thick near base, 0.5–1.0 cm thick near apex, squamose, suberect to semidecumbent, prominently marked with leaf-scars, at first nearly white-glaucous, later strongly violet-glaucous except for a dark olive-green area within 4.0 mm of each leaf-scar; leaf-scars ca. 4.0 mm wide and 2.0–3.0 mm high, elliptical, tan; rosettes 4.0–4.5 × 9.0–14.0 cm, 12–20 leaves per rosette. Leaves 4.0–5.5 (6.4) × 2.0– 2.5 cm, 1.5–2.0 cm from apex, 4.0–7.0 mm wide at base, 5.0–7.0 mm thick at thickest part ca. 5.0 mm from apex, ca. 4.0 mm thick, ca. 1.0 cm from base, thickening again near base to 5.0–6.0 mm, ovate-oblong when young, later oblong-obovate, the upper surface nearly flat to slightly convex, or somewhat concave along basal half, the lower surface more or less strongly convex, obtusely keeled along whole length, with an obscure obtuse spur near point of attachment, the more apical ones in a dense, nearly flat rosette, the lower ones separated 5.0–8.0 mm at base, the youngest slightly ascending, the older ones spreading to slightly reflexed, soon deciduous, heavily glaucous with dark purplish bloom in winter, less purplish in summer, the epidermis ambergray beneath wax; margin acute along basal half, more obtuse toward apex; apical mucro 1.0– 1.5 mm long and wide, deltoid. Inflorescences up to 3 to a stem, emerging laterally ca. 6.0–8.0 cm below stem-apex, 30.0–40.0 cm long and ca. 2.0–3.0 mm wide at base or middle, erect or ascending-horizontal, diffuse and much-extended, pyramidal or oblong in outline, peduncle 7.0–12.0 cm long, ca. 5.0 mm thick, glaucous like the stem, rachis 1.0–3.0 mm thick; bracts lacking on basal 2.0–3.0 cm of peduncle, ca. 10 above, similar to leaves but smaller; number of flowers per full-sized inflorescence 57–121; branches 12–15, ca. 2.0–4.0 cm apart, the lower ones usually divaricately once-branched, the upper usually unbranched, the rachis ca. 1 mm thick along basal half and ca. 0.5 mm thick above, with 5–9 flowers; pedicels 1.0– 1.4 cm long, ca. 0.75 mm thick, ascending and straight, or horizontal and becoming erect just below calyx, 1.5–3.0 cm apart. Flowers 15–16 mm; calyx disc ca. 3.0 mm wide; calyx lobes appressed to corolla lobes, 3–4 mm long, ca. 1.0 mm wide at middle, narrowly lanceolate, subacute, glaucous and colored like leaves; corolla ca. 9.0 mm long when unopened, 15.0–16.0 mm wide when expanded; corolla tube 2.9–3.1 mm, corolla lobes 5(–6) mm long, 2.0– 2.75 mm wide, triangular, acute, the upper surface grooved longitudinally, minutely papillose along depression, sharply keeled on the lower side, the upper surface greenish yellow, the apical millimeter reddish brown, the next 2.0 mm with 2–3 crossbands and scattered dots of same color; nectaries ca. 0.5 mm high and 1.0 mm wide, truncate; stamens 5(–6), 6.0–7.0 mm long, ca. 0.5 mm wide, antesepalous, at first erect, later reflexed between the corolla lobes, greenish yellow, the apical half red-dotted; gynoecium ca. 7.0 × 3.5 mm thick, obovoid, greenish yellow, reddened apically; styles less than 1.0 mm long. Fruits 5.3–5.9 × 1.4–1.6 mm; seeds 0.35–0.42 × 0.15–0.19 mm.

Notes:—Similar to Quetzalcoatlia pentandra , the stems are 0.8–1.2 cm thick, rosette 6.0–8.0 cm wide, leaves 4.0–6.0 cm long, 2.0– 2.5 cm wide, gray-purple, primary axis 30–40 cm long, stamens 5 (rarely 6). Quetzalcoatlia superba is distinguished from Q. pentandra by its larger size, the squamous surface of the stem, the pink-violet color of the rosette, leaves oblong-obovate, and a profusely branched inflorescence (see Table 1). Gametic chromosome number: n = 64 ( Kimnach 1987).

Relationships:—Molecular and morphological cladistic analyses indicate that three species of Quetzalcoatlia (treated as Gratopetalum): Q. glassii , Q. itzicuaroensis , and Q. superba are closely related and belong to a strongly supported clade occurring in the area of Nueva Galicia in western Mexico ( Acevedo-Rosas et al. 2004a, 2004b). Among the characters they share are stamens in a single whorl (haplostemonous flowers) instead of ten in two whorls, as in the genus Graptopetalum . Among Crassulaceae , only certain genera of Sedoideae and all the representatives in the Crassuloideae include haplostemonous species, all of which are from the Old World ( Berger, 1930).

Distribution, habitat, and phenology: — Endemic to the ravine of the Juchitlán river, growing at 1200 m a.s.l in tropical dry forest with Agave angustifolia Haw. , Aleuritopteris farinosa (Forssk.) Fée , Bursera sp. , Spondias mombin L., Stenocereus sp. , Tabebuia rosea (Bertol.) DC. and Tillandsia capitata Griseb. It flowers from April to May and fruits in June.

Etymology:—The specific epithet means very beautiful, due to the purplish color of its large rosettes.

Notes:—In 1985, Ricardo Ornelas and Agustín Flores from Universidad de Guadalajara found this species at Los Corrales, Juchitlán; however, it was at a sterile stage and no herbarium specimen was kept. Luis Aviña , a physician of La Barca city, state of Jalisco, bought a Graptopetalum plant from an unknown locality and it was sent to the Huntington Botanical Garden, and upon flowering it was named as Graptopetalum pentandrum subsp. superbum by Myron Kimnach (1987). In May 1990 Flores, Cházaro, Servando Carvajal, and Antonio Machuca returned to Los Corrales and found in flower the first wild population of Graptopetalum pentandrum subsp. superbum ( Cházaro-Basáñez & Flores 1992), which now corresponds to Quetzalcoatlia superba .

Preliminary conservation assessment:—Following the IUCN Red List criteria B1ab(iii) ( IUCN 2022), the species was assessed as Critically Endangered (CR). The EOO is less than 100 km 2 (criterion B1); the AOO is <10 km 2 (B2); this species is only known from a single location (condition a); and we inferred a decline in the quality of its habitat (condition b(iii)) through land use change and over-collecting. This species is being reproduced in private collections.

Additional specimens examined:— MEXICO. Jalisco: municipality Juchitlán, Cañada rocosa cerca de Los Corrales, al E de Juchitlán, 1200 m, M. Cházaro-Basáñez et al. 6929 ( IBUG!) ; Barranquilla, 1 km al N de Los Corrales camino a Los Guajes , 13 May 1990, M. Cházaro B. et al. 6215 (ENCB!, IEB!, MEXU!, MO!, MICH!, XAL!, WIS!) ; Cerca de Los Corrales, Juchitlán-Los Guajes , 12 May 1991, M. Cházaro-Basáñez, et al. 6647 ( XAL!) ; Same locality, 3 May 1992, M. Cházaro-Basáñez et al. 6926 ( XAL!) ; Cultivada de planta de Jalisco, 20 March 1997, I. García & J.A. Machuca 4622 ( CIMI!) ; Cultivada Guadalajara , 10 April 1999, I. García 5590 ( CIMI!) .

Quetzalcoatlia trujilloi (A. Vázquez & Rosales ) A. Vázquez & Rosales, Boletín Nakari 34(2): 39 (2023) ( Figs. 1–3 & 23 ).

≡ Graptopetalum trujilloi A. Vázquez & Rosales, Phytotaxa 532(3): 282 (2022) .

Type:— MEXICO. Jalisco: municipality of San Gabriel, 4 km N of San Gabriel, 1390 m, 7 September 2008, J. Antonio Vázquez-García 8835, with J. Trujillo, J. Etter, M. Kristen & M. Cházaro (holotype IBUG!, isotypes CIMI!, ZEA!).

Description:—Plants suffrutex, perennial, 15.0–35.0(–41) cm tall without inflorescence, caulescent, ramose, branching basally; stems 8.0–27.0 × 0.6–0.8 cm, decumbent to pendant, surface smooth, brownish, at the base; leaf scars 1.0–2.0 mm in diameter, oval to circular, bumped and dark greenish, the tip soon dries; rosettes terminal, 7.0– 8.0 × 9.0–11.0(–12.0) cm, with 15–32(–52) leaves. Leaves 4.0–7.5 × 2.3–2.8 cm, 6.0–9.0 mm thick, obovate to oblanceolate, glabrous, adaxially slightly concave, abaxially convex, glaucous greenish to pinkish; margins entire and rounded, convolute toward the apex; the base cuneate, the stalk-like, basal portion 5.0–6.0 mm wide, the apex acute, in right angle or obtuse; apical mucro 1.0–3 × 1.0–3.0 mm, the tips yellowish to pinkish. Inflorescences 15.0–32.0 × 0.7–11.9 cm, oblongoid dense, 30–50 flowers on 7–10 simple or bifurcate branches, each branch spaced 2.0– 3.4 cm with 3–7 flowers, the basal branch with 3–6 flowers; the fertile portion 24.0–25.0 cm along the primary axis; primary axis 2.0–3.0 mm thick at the base, distally 1.0 mm thick, gray-bluish to pinkish, mean flower density per 10 cm of the primary axis 17–20; bracts on primary axis soon deciduous, 10–13, 1.0–3.0 × 0.9–1.0 mm, lanceolate to elliptic; panicle branches 2.0–6.0 × 0.1.5– 0.2 cm, simple or bifurcate, with 3–6 flowers each, 3–5 in the basal branch; bracteoles 1.7–1.8 × 0.9–1.3 mm, lanceolate, glaucous greenish; pedicels 0.9–1.1 × 0.07–0.09 cm long; flower buds 6.4–6.5 × 5.3–5.4 mm. Flowers 12.9–13.1 mm in diameter; calyx fused 0.4–0.5 mm × 1.4–1.5 mm; calyx lobes 2.3–2.0 × 1.2–1.3 mm; corolla tube 3.7–3.8 × 3.0– 3.4 mm; corolla lobes 4.9–5.2 × 2.7–2.8 mm, triangular, subequal, proximally greenish to distally red and striped, longitudinally with a shallow groove; nectaries 0.7 × 0.9 mm, bright yellow; stamens (4–)5, erect in the early stage of anthesis, later reflexed; filaments 7.2–7.4 × 0.2–0.5 mm, greenish to distally red; anthers 0.4 × 0.2 mm, ellipsoid, beige, becoming blackish; gynoecium 7.2–7.3 × 3.2–3.3 mm, carpels 7.0–7.1 × 1.1–1.3 mm, carpels obtuse, abaxially greenish to pinkish; styles 1.1–1.2 × 0.3–0.4 mm; stigmas 0.1–0.2 mm. Fruits costate oblongoid, 7.4–7.6 × 3.2–3.4 mm; oblongoid; seeds unknown.

Notes:— Quetzalcoatlia trujilloi is similar to Q. rosanevadoensis in sharing a ramose habit, smooth stem surface, and stem diameter, but it differs from the latter in having a smaller habit 15.0–35.0(–41.0) vs. 40.0–87.0 cm, more numerous branches per inflorescence 7–10 vs. 5–6, larger mean flower density per 10.0 cm of the scape 17–20 vs. 6–9, fewer flowers per basal branch 3–5 vs. 6–7, smaller flower diameter 12.9–13.1 vs. 14.9–15.1, petals greenish with transversal inconspicuous red stripes vs. yellowish with transversal conspicuous red stripes, petal width 2.7–2.8 vs. 2.9–3.0 mm, filaments greenish to distally red vs. red and carpels abaxially obtuse vs. rounded. It is also similar to Q. superba in sharing a ramose habit, similar rosette diameter and similar mean flower density per 10.0 cm of the scape, but it differs from the latter in having a smaller habit 15.0–35.0 (–41.0) vs. 40.0–80.0 cm, stem surface smooth vs. squamous, smaller stem diameter 6.0–8.0 vs. 10.0–12.0 mm, less numerous branches per inflorescence 7–10 vs. 12–15, and smaller flower diameter 12.9–13.1 vs. 15.0–16.0 mm. In September 2008, J. A. Vázquez-García and collaborators visited San Gabriel municipality, Jalisco, and collected plants of a Quetzalcoatlia species (at that time identified as Graptopetalum ) which later bloomed in Zapopan, Jalisco, these populations were revisited by Santiago Rosales in 2021 to confirm that this population actually belongs to an undescribed species. Quetzalcoatlia trujilloi is under cultivation mostly in private collections.

Distribution, habitat, and phenology: — Graptopetalum trujilloi is known only from populations at the type locality, on vertical slopes of the southern region of Jalisco, north of San Gabriel, in tropical deciduous forest, at an elevation of approximately 1390–1410 m, with Agave pedunculifera Trel. , Astrolepis sinuata (Lag. ex Sw.) D.M. Benham & Windham , Dioscorea sp. , Euphorbia sp. , Peperomia sp. , Sedum chazaroi P. Carrillo & J.A. Lomelí and Tillandsia sp. It flowers in early March and sets fruit in early June.

Etymology: —The specific epithet honors Jesús Trujillo , an outstanding explorer of the Gran Barranca de Guadalajara and expert in succulent cultivation who contributed to the discovery of this species.

Preliminary conservation assessment:—Following the IUCN Red List criteria B1ab(iii) ( IUCN (2022), the species was assessed as Critically Endangered (CR). The EOO is less than 100 km 2; (criterion B1); the AOO is <10 km 2 (B2); this species is only known from a single location (condition a); and we inferred a decline in the quality of its habitat (condition b(iii)) through land use change and over-collecting.

Additional specimens examined:— MEXICO. Jalisco: San Gabriel municipality, 4 km north of San Gabriel, 1410 m, 27 June 2021 (sterile), S. Rosales et al. 1 ( IBUG), same location, 27 June 2021 (infructescence), S. Rosales et al. 2 ( 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 22. Quetzalcoatlia superba, from Los Corrales, Juchitlán, Jalisco. Photographs:A–E by J. Etter & M. Kristen; F. by A.Vázquez- García (cult.).

FIGURE 23. Quetzalcoatlia trujilloi, from Sierra de Tapalpa, San Gabriel, Jalisco. Photographs: A–B & I by Santiago Rosales, C by A. Vázquez-García, D–H by J. Etter & M. Kristen.