Asclepias graogramanii L.O. Alvarado, M.G. Chávez & J.A. Alvarez, 2023

Chávez-Hernández, María Guadalupe, Álvarez-Ruiz, Julio Alejandro & Alvarado-Cárdenas, Leonardo Osvaldo, 2023, Two new Mexican species of Asclepias (Apocynaceae; Asclepiadoideae; Asclepiadeae), Phytotaxa 592 (3), pp. 255-266 : 261-262

Asclepias graogramanii L.O. Alvarado, M.G. Chávez & J.A. Alvarez sp. nov.

Type: — MÉXICO. Jalisco: Mascota , Ca. 4 mi. S of Mascota, 1400 m, 20°27’24’’N 104°46’24’’W, 1 May 1951, R. McVaugh & D.V. Hoover 12211 (Holotype: MEXU!) .

Asclepias graogramanii is morphologically similar A. glaucescens due to its sessile and oblong to lanceolate leaves and the gynostegial corona with conspicuous hoods and its horns perpendicular or diagonal to the hoods, but differs from this taxon by its pink corolla lobes (vs. green to white in A. glaucescens ), its sessile gynostegium (vs. short to clearly stipitate gynostegium), its hoods cylindrical to oblongoid, and rarely slightly conduplicated, of the same size or smaller than the gynostegium (vs. hoods oblongoid, conduplicated and taller than the gynostegium in A. glaucescens ), and its pink with purple in the base hoods (vs. white or yellowish in A. glaucescens )..

Perennial herb 30-80 cm tall. Stem single, cylindrical, branched, densely puberulent, internodes 6.8–11.5 cm long Leaves opposite, 6–10 pairs, sessile, oblong to lanceolate, sometimes oblong, base truncate to slightly cordate, apex acute, 6.1–12.2 cm long × (1.4)2.7–3.9(4.8) cm wide, margin entire, shortly pubescent adaxially, trichomes erect, more dense at the midvein, shortly pubescent abaxially, brochidodromous venation, 10–25 pair of veins, a pair of glandular multicellular trichomes (colleters) present in a stipular position. Inflorescences of 1–3 umbels adjacent to upper leaf axils, the last produced sometimes appearing terminal, on densely pubescent peduncles (4.2)5.6–9.6(13.5) cm long, bracts linear to lanceolate, 3–4 mm long, caducous; umbels of (8)14–20(33) flowers on pubescent pedicels 1.4–2.8 cm long. Calyx lobes ovate-lanceolate, reflexed, green, 3–4.2 mm long × 1.2–2 mm wide, abaxially puberulent. Corolla lobes ovate, reflexed, pink to white-pinkish, 0.5–0.8 cm long × 0.3–0.5 cm wide, glabrous. Gynostegium sessile, corona composed of five purple to pink, cucullate segments (hoods) opposite the filaments, cylindrical to oblongoid, and sometimes slightly conduplicated, 3 mm tall in its adaxial side, apex acute, without touching the gynostegium, 4–5 mm tall in its abaxial side, acute, each hood with a digitate appendage (horn), curved, white, 1 mm long, adnate to the dorsal surface of the hood and emerging from the hood’s sinus; anthers brown, 1.5–2 mm long, the lateral margins with corneus, with ovate white appendages inflexed over the apex of style head, style head 2 mm diameter, pentagonal, apex convex; pollinarium composed of a pair of pollinia 0.8–1 mm long, oblong-ovate, translator arms 0.7–0.8 mm long, linear, corpusculum 0.35–0.4 mm long, broadly elliptic to subcircular, black. Fruits fusiform follicles, 9–15 cm long, densely puberulent, held erect on an erect stalk; seeds not observed. ( Fig. 3 ).

Phenology & ecology:— Flowering occurs between April and July, and the fruiting in the months of May to October.

Distribution & habitat:— The new species is endemic to Mexico and distributed in Jalisco and Nayarit.

Habitat and ecology:—Growing in oak-pine forest and secondary vegetation derived thereof. It can also grow in xerophytic scrub and secondary vegetation derived, as well as beside the roads. The species grows on elevations between 900 to 1106 m a.s.l. ( Fig. 3 ). The species is visited by two different species of ants and the Apis mellifera bee ( Fig. 3E ), and parasited by Aphis nerii and a milkweed bug ( Lygaeidae family).

Etymology:— The name of the new species refers to the fictional character Graograman, a multicolored lion from Michael Ende’s novel “The Neverending Story”, due to the colorful flowers.

Proposed conservation assessment: — Vulnerable (VU B1b(iii)+B2b(iii) ( IUCN 2022)). Asclepias graogramanii has a minimum Area of Occupancy (AOO) of 60 km 2, and an estimated Extent of Occurrence (EOO) of 15,209.643 km 2. One of its populations grows in the Zona de Protección Forestal y Refugio de Fauna Silvestre “La Primavera”. Observations by the second author (Julio Alejandro Álvarez-Ruiz) in the field point out that plant populations are scarce, but it seems to tolerate the disturbance and grows in secondary vegetation or along roads.

Notes:— This species is similar to A. glaucescens and usually misidentified as A. elata Bentham (1849: 290) or A. macroura in herbarium specimens ( Fig. 4 ). Asclepias graogramanii is similar to those species due to its sessile and oblong to lanceolate leaves and the morphology of the gynostegial corona ( Woodson 1954, Stevens 2009).

The new species can be separated from morphological similar taxa based on the following differences: pink corolla lobes (vs. green in A. elata and A. macroura and green to white in A. glaucescens ), its sessile gynostegium (vs. short to clearly stipitate gynostegium in A. glaucescens ), its hoods cylindrical to oblongoid, and rarely slightly conduplicated, of the same size or smaller than the gynostegium (vs. hoods oblongoid, conduplicated and taller than the gynostegium in A. glaucescens ), its pink with purple in the base hoods (vs. white with green to yellowish in the base in A. elata , white or yellowish in A. glaucescens , and green or white in A. macroura ), its horns perpendicular or diagonal to the hoods, rested on the gynostegium (vs. horns without touching the gynostegium in A. elata , and erect and curved horns in A. macroura ).

Additional specimens examined:— MÉXICO. Jalisco: Jocotepec , Fields, San Marcos, C. G. Pringle 4399 ( MEXU) . Nayarit: Compostela, Rancho de los platanitos, San Blas, J. González-Ortega w/n ( MEXU). Jala, 15 km al NE de Jalpa, Volcán el Ceboruco , G. Flores-Franco 1902 ( MEXU); Ca. 5 mi. NW of Tepic , on grassy hills, R. McVaugh 12089 ( MEXU); El Presidio , 9 km al SW del entronque de la carretera El Izote-Jalcocotan , camino al Cuarenteño o 500 m al W de El Rancho La Noria, G. Flores-Franco 3447 ( MEXU). Xalisco, 8 km al NW del entronque a Cofradia de Chocolon-Xalisco , G. Flores-Franco 3499 ( MEXU) .

Additional observation from Naturalista examined:— MÉXICO. Jalisco: Mascota, E. Canales 3447911 (Naturalista, https://www.naturalista.mx/observations/3447911); Paisaje biocultural, F. Esparza 42674686 (Naturalista, https://www.naturalista.mx/observations/42674686). Tepic, Tepic, V. Luja 24009756 (Naturalista, https://www. naturalista.mx/observations/24009756). Zapopan, Bosque La Primavera, J. A. Álvarez-Ruiz 22547425 (Naturalista, https://www.naturalista.mx/observations/22547425), J.A.Álvarez-Ruiz 22547427 (Naturalista, https://www.naturalista. mx/observations/22547427), M. Castillo 28703220 (Naturalista, https://www.naturalista.mx/observations/28703220), V. Shalisko 11287784 (Naturalista, https://www.naturalista.mx/observations/11287784); Zona metropolitana de Guadalajara, A. Galindo 55296707 (Naturalista, https://www.naturalista.mx/observations/55296707). Nayarit: Cuencas, Tanniae 45337944 (Naturalista, https://www.naturalista.mx/observations/45337944). Tepic, Alrededores de Tepic, A. Türkmen 20776897 (Naturalista https://www.naturalista.mx/observations/20776897), N. Campos 42234168 (Naturalista, https://www.naturalista.mx/observations/42234168); Xalisco, D. Amador 42908315 (Naturalista, https:// www.naturalista.mx/observations/42908315).

Figures

FIGURE 3. Asclepias graogramanii. A. Known distribution of A. graogramanii and morphological related species in the region of study. B. Habit. C, D. Inflorescences. E. Apis mellifera. Photographies from Naturalista by Julio Álvarez (B, C, D), and Eréndira Canales (E).

FIGURE 4. Comparison between flowers and types of Asclepias graogramanii and morphological related species. 1. A. graogramanii. 2. A. elata. 3. A. glaucescens. 4. A. macroura. Photographies from Naturalista by Julio Álvarez (1a, 3a, 3b, 4b), Muny Castillo (1b), Leticia Jiménez Hernández (2a), and Emmanuel Guevara Lazcano (4a).Types of the morphological related species.A. graogramanii (R. McVaugh 12211, MEXU!) (1c). A. elata (K.T. Hartweg s.n., K!) (2c). A. glaucescens (A.J.A. Bonpland & F.W.H.A. von Humboldt, 3920, P!) (3c). A. macroura (E. Palmer 344, GH!) (4c). Scale bar 1 cm.