Graptopetalum rosanevadoensis A. Vázquez & Acev., 2021

Vázquez-García, J. Antonio, Acevedo-Rosas, Raúl, Cházaro-Basáñez, Miguel, Nieves-Hernández, Gregorio & Sahagún-Godínez, Eduardo, 2021, Graptopetalum rosanevadoensis (Crassulaceae): A new haplostemonous species from the Nevado de Colima, Jalisco, Mexico, Phytotaxa 496 (2), pp. 159-169 : 162-168

Graptopetalum rosanevadoensis A. Vázquez & Acev. -Rosas sp. nov. ( Figs. 1–4 ).

Diagnosis:— It is similar to Graptopetalum superbum in sharing a non-caespitose and ramose habit, similar stem length and oblong obovate leaves, but it differs from the latter in having a stem surface smooth vs. squamose, stem diameter 0.7–0.8 vs. 1.0–1.2, leaves per rosettes 31–47 vs. 12–28, leaf color glaucous to brownish green, pinkish when young vs. grey-blue to pink-violet, inflorescence length 9.8–27.5 vs. 30.0–40.0, and branches per inflorescence 5-6 vs. 12-15. It is also similar to G. pentandrum in stem length with smooth surface and color pattern of petals, but it differs from the latter in having a habit none caespitose ramose vs. caespitose-ramose, rosette diameter 10.0–16.0 vs. 6.0– 8 cm, stem diameter 0.7–0.8 vs. 0.3–0.6 cm, leaves 31–47 vs. 12–20, leaf color glaucous to brownish green, pinkish when young vs. blue-green to white blue, branches per panicle 5–6 vs. 3–4.

Type:— MÉXICO. Jalisco: Nevado de Colima, Cuenca del Río Alseseca, Los Lavaderos, Zapotitlán de Vadillo , 4 km E of Telcruz, on a vertical sandy slope of NW exposure, 1400 m, fl 7 May 2005, J. A . Vázquez-García. 7990, with M . Cházaro , N . Contreras and R . Murguía (holotype: IBUG; isotypes: MO, NY) .

Plant perennial, ramose, a sparse terminal rosette 10.0–16.0 cm diam.; stems 40.0–87.0 cm tall, decumbent, pendulous, smooth, 7.0–8.0 mm diam.; leaves 31–47, (1.5-) 3.0– 4.0 (-5.9) × (1.4-) 1.6–1.8 (-1.9) cm, (4.0-)5.0–7.0 (-8.0) mm thick, inner surface slightly concave, oblong–obovate, obtuse to rounded, sometimes with a short apical mucro, cuneate at the base, glaucous to brownish green, pinkish when young; scape 1.5–4.0 mm thick at the base, 1 mm thick at the top; panicle (9.8-) 10.5–20.3 (-27.5) cm long, 5–6 branches per inflorescence; bracts 23–29, ovoid, the lowest 1.9–3.1 cm long, the uppermost bracts 2.0–3.0 mm long, soon deciduous; panicle branches 2.4–4.3 cm long, simple or bifurcate, with 2–4 flowers each; pedicels 3.0–14.0 mm long; flower buds 3.0 × 3.0 mm; sepals 5, 3.0 mm long, distinct, appressed; petals 5, pale yellowish-green or pale yellowish, with red to wine red dots, these forming horizontal bands across the petals, mainly at the apex; nectary scales [wanting]; stamens 5, alternate to the petals, at first erect, later completely recurved, filaments white with the apical half dotted with red or pinkish red; gynoecium ca. 0.5 cm long, obovate, yellow green, style 0.9 mm, orange, red-orange or dark red apically.

Distribution, habitat and phenology:— Graptopetalum rosanevadoensis is known only from several large populations (10-20 individuals each) at and near the type locality, on the western slopes of the Nevado de Colima, found in various creeks of tributaries of the Alseseca river, at 1400 m on shallow sandy soils, on vertical slopes of protected ravines with a tropical dry forest surrounded by oak forest on the adjacent hills. Flowering in May and perhaps in November as we were told by local inhabitants.

Eponymy and Ethnobotany:—The specific epithet honors Ing. Rosa Murguía Araiza, an energetic and enthusiastic silviculturist and conservation activist, from Zapotitlán de Vadillo, Jalisco, on the SW slopes of Nevado de Colima, where she discovered this species. The hanging rosettes are called “chonguitos”. Smashed leaves are used for eye cleaning, rosettes are collected and grown in the backyards as ornamentals, the leaves are often eaten by birds (especially sparrows) while in flower pots.

Additional specimens examined:— MÉXICO. Jalisco: Las Goteras, Los González, Ejido de Zapotitlán de Vadillo , 15 May 2005, R . Murguía-A. 21 ( IBUG); Punta del Plan, Municipio de Zapoptitlán de Vadillo , 15 May 2005, R . Murguía-A. 27 ( IBUG); Bajada del Borrego, Municipio de Zapotitlán de Vadillo , 15 May 2005, R . Murguía-A. 32 (IBUG).

Figures

FIGURE 1. Distribution map for the haplostemonous species of Graptopetalum.

FIGURE 2. Graptopetalum rosanevadoensis. A. Habit in perspective, the focal point, on terminal inflorescence, appearing larger than it is. B. Vegetative growth. C. Leaf in ventral view. D. Leaf in lateral view (a–a’, b–b’, cross-sections of the leaf). E. Front view of the flower. F. Lateral view of the flower and pedicel. G. Petal detail. H. Gynoecium with nectary scale. I. Anther detail (drawn from the holotype by David Jimeno).

FIGURE 3. Graptopetalum rosanevadoensis, grown from type collection at Jesús Trujillo’s home (in Guadalajara; photo: April 11, 2012).

FIGURE 4. Graptopetalum rosanevadoensis. A–B. Inverted J-shaped hanging habit of rosettes [at the type locality, photo: May 15, 2005]. C. Rosettes and inflorescence (upper view). D. Flower after anthesis. E. Flower at anthesis. F. Lateral view of a dissected flower. G. Rosette and inflorescence, lateral view. C–H from cultivated plants (grown from the type collection, photo: April 10, 2012). Flower dimensions in mm.