Agave igni A.Vázquez, Padilla-Lepe, 2025

Vázquez-García, J. Antonio, Padilla-Lepe, Jesús, Guerrero-Jaime, Ismael, Cuevas-Mendoza, María G., Acosta-García, Jesús A., Vázquez, María Esthela, González-Gutiérrez, Sergio Armando & Hernández-Vera, Gerardo, 2025, Agave igni (Agavaceae, Asparagales), a new species from El Llano en Llamas region of Jalisco and Colima, Mexico, Phytotaxa 701 (1), pp. 69-81 : 70-78

Agave igni A.Vázquez, Padilla-Lepe & I. Guerrero sp. nov. ( Figs. 2–6 ).

Type:— MÉXICO: Jalisco. Municipio Tolimán, cerca de Taberna de Don Santos, Tajipo, Cuenca del Río Armería, Municipio de Tolimán, 725 m of elevation, 19.528123° -103.888242°, 20 Marzo 2023 (fl & fr), laderas de aluviones con bosque tropical caducifolio dominado por Stenocereus queretaroensis , Plumeria rubra , Pseudosmodingium perniciosum,Cephalocereus alensis, Mammillaria beneckei, J. Antonio Vázquez-García 10262 w/ Ismael Guerrero-Jaime, Jesús Padilla-Lepe, María G. Cuevas-Mendoza, Jesús A. Acosta-García & Claudia F. G. Martínez-Ruvalcaba (holotype IBUG!, isotypes ZEA, ENCB, MEXU, IEB).

Diagnosis:— Agave igni is similar to A. colimana in having open rosettes with filiferous leaf margins and leaves with bud-printing of grayish-white lines. However, it differs from the latter in having less numerous leaves per full-size rosette (200–250 vs. 284–502), arched inflorescence vs. mostly straight, shorter ovary length (14.0–15.0 vs. 15.3–20.0 mm), corolla segments longer than tubes,

shorter tepals (14.0–15.0 vs. 16.2–23.0 mm), shorter fruits (19.0–20.0 vs. 26.4–30.3 mm), and longer flowering/fruiting periods (9/5 vs. 4/4 months).

Description:—Plants perennial, monocarpic, solitary, acaulescent; rosettes 100–120 cm in diameter, up to 90 cm tall, open, hemispherical, green to pale green; leaves 200–250 per rosette 40.0–59.0 × 1.7–3.8 cm, linear, slightly adaxially concave, rigid, green to pale green, usually with faint lines of white impressions; margins somewhat fibrous, with 3–14 threads per side, 3–15 cm long, grey to grayish white; terminal spine, 4.0–7.0 × 2.0– 2.5 mm, brown; inflorescences 3– 5 m long, usually arched or inclined, dense, fully covering the rachis; the shaft 5.5–6.0 cm at the base, infertile portion 0.6–1.5 m long, fertile portion up to 3.5 m long; basal bracts on the peduncle 18.0–20.0 × 0.7–1.0 cm, triangular, flexible, yellowish-green with a fine dark reddish tip; bracts on the fertile part, 7.0–8.0 cm long; peduncular bracts 1.4–1.6 cm long, peduncles 6.0–7.0 mm long, bracteoles, 4.0 × 2.5 mm, almond-shaped ocher tip, pedicels 4.0–5.0 × 2.5 mm, brown, flowers 48.0–55.0 mm long, corolla tubes 15.0–16.0 × 8.0– 8.5 mm, yellowish green, tepal lobes 14.0–15.0 × 4.0–5.0 mm, recurved to curled, yellowish green, with whitish hyaline margin, filaments 4.7–5.2 cm long, yellow-ocher, anthers 11.0–22.0 mm long, bright yellow; ovaries 14.0–15.0 × 3.5–4.0 mm, green, ovary necks 1.5–1.6 × 2.8–3.0 mm; styles keep elongating after pollination, up to surpassing 1/3 the length the stamens, whitish; stigmas clavate, yellowish green; fruits 19.0–20.0 × 8.5–9.5 mm, oblongoid, brown; seeds 3.9–4.0 × 3.0– 3.1 mm, slightly angular, with corners rounded, opaque, black.

Distribution and ecology:— The species occurs from Minatitlán, Colima, to Tolimán, Jalisco, on the eastern flanks of the calcareous massif Cerro Grande massif, Sierra de Manantlán, and the lower western igneous slopes and ravines of the Nevado de Colima, Volcano; at elevations from 725 to 1200 m; growing on tropical dry forests, flowering from October to June, fruiting from February to June.

Conservation status: —The species grows abundantly on cliffs and rocky slopes, within thorn and tropical dry forests, confined to a few locations. Using a 2 km cell width in GeoCAT ( Bachman et al. 2011), Agave igni has an Extent of Occurrence (EOO) of 10.977 km 2 and an Area of Occupancy (AOO) of 12.000 km 2. Following the IUCN (2022) categories and criteria, the species is considered Critically Endangered given its small EOO. It is currently being propagated at the greenhouses of the Instituto de Botánica, Universidad de Guadalajara, Mexico. Cattle and agricultural expansion for local mezcal production (mainly from Agave angustifolia Haworth (1812: 72) , A. rhodacantha Trelease (1920: 117) and occasionally A. tequilana) are increasingly affecting the size of populations of this species, especially at their lower slopes.

Biocultural relevance:— The specific epithet of Agave igni is in allusion to Juan Rulfo´s book of short stories “El Llano en Llamas” (The Plain in Flames); this species grows near the inhospitable arid region that inspired the book, on the Armería watershed, an area of high endemism and a relevant center for diversification of Agavaceae and Crassulaceae . It also refers to the flowering inflorescence, resembling a flare of a mast on fire.

History:— Agave igni was first collected in fruit in February 1987 (Cházaro & Santana-Michel 4468) on the eastern slopes of the Cerro Grande, Sierra de Manantlán, Minatitlán, determined as A. schidigera ; subsequently in October 1990, on the same locality, flowers were collected (Cházaro et al. 6450) but it was identified as A. colimana . In January 1996, a second population in Barranca del Huisichi, Tolimán ( Machuca & Cházaro 7811) was also identified as A. colimana . In 2019, material collected from Barranca Huisichi ( Morales s.n.) bloomed at ITESO in 2022. In 2023, a mezcal-route expedition of the Agavaceae course, led by the first author, from Colima to southern Jalisco, allowed Jesús Padilla-Lepe to spot the third and largest population of the newly proposed species (Vázquez-García et al. 10262) at Tajipo, Tolimán, Jalisco.

Specimens examined:— MEXICO. Colima: Minatitlán, cerca de Campo 4, camino viejo a El Terrero , Cerro Grande , Sierra de Manantlán , 1200 m of elevation, 23 February 1987 (fr), Cházaro & Santana-Michel 4468 (IBUG) ; same locality, brecha de Juluapan a Lagunitas , 17 October 1990, Cházaro et al. 6450 (MEXU, WIS) . Jalisco: Tolimán, Barranca del Huisichi , 1100 m of elevation, 28 January 1996 (fl), Machuca & Cházaro 7811 (MEXU) ; same locality, May 2013, Morales-Padilla 49, picture of a living plant that bloomed in 2022 at ITESO. Municipio Tolimán, cerca de Taberna de Don Santos, Tajipo, Cuenca del río Armería , Municipio de Tolimán , 725 m of elevation, 20 June 2023 (fr), V ázquez-García & Padilla-Lepe 10267 (IBUG) .

Figures

FIGURE 2. Flowers, inflorescences and rosettes of Agave igni and morphologically close species. Photographs by A. Vázquez, except those of the in situ inflorescence and rosette of A. schidigera by A. Faurrieta.

FIGURE 3. Agave igni in situ. Inflorescence at Tajipo, Canoas, Tolimán, Jalisco. Showing different stages from flower buds at the top to developing fruits at the bottom. Photograph by A. Vázquez

FIGURE 4. Agave igni in situ at Tajipo, Canoas, Tolimán, Jalisco. A–B. Inflorescences. Photographs by A. Vázquez.

FIGURE 5. A–C: Agave igni, rosette variability in the type locality. D–F: A. colimana near the type locality at Manzanillo, Colima. Photographs by A. Vázquez.

FIGURE 6. Inflorescence of Agave igni. A. Flower buds opening. B. Flowers at anthesis with fully extended stamens. C. Flower buds. D. The three flowering stages from base to top, flowers past anthesis with accrescent white style, flowers at anthesis in the middle, and flower buds at the top. Photographs by A. Vázquez.