Tigridia azufresensis López-Pérez & Munguía-Lino, 2023

López-Pérez, Jorge David, Rodríguez, Aarón & Munguía-Lino, Guadalupe, 2023, A new species and endemism of Tigridia (Tigridieae, Iridaceae) in the Transmexican Volcanic Belt, Mexico, Phytotaxa 603 (3), pp. 249-259 : 250-255

Tigridia azufresensis López-Pérez & Munguía-Lino , sp. nov. ( Figs. 1 and 2 , Table 1 ).

Diagnosis:— Bulbous herb 12.5–38 cm tall, basal leaves 9.8–41.5 × 0.5–0.7 cm, scape unbranched, cauline leaf plicate on the distal portion, as long as or longer than the inflorescence, outer tepals elliptic to elliptic-lanceolate, inner tepals with a distinctive claw, geniculate blade and limb triangular and apiculate, tepals pale lavender to blue-lavender, the base with blue-lavender macula, blade with bright yellow edges, nectary covered by a folded blade.

TYPE:— MEXICO. Michoacán: Ciudad Hidalgo, Parque Nacional Los Azufres , en el patio de Los Chinos, 19°48’32.10”N, 100°40’2.35”W, 2948 m, 8 August 2021, G. Munguía-Lino et al. 921 (holotype IBUG!, isotypes CIIDIR!, IEB!, MEXU!) .

Description:— Bulbous, perennial erect herb, 12.5–38 cm tall, glabrous; bulb ovoid, 2.0–3.5 × 0.8–1.8 cm, outer tunics light reddish brown (greyed-orange group 166B); basal leaves 2–3, linear, plicate, 9.8–41.5 × 0.5–0.7 cm, equalling or longer than the inflorescence at anthesis; scape unbranched, 6.5–28 cm tall; cauline leaf plicate, 3.5–9.0 × 0.3–0.4 cm; rhipidium 1, with 2 amplexicaule spathe-bracts, equalling or shorter than the cauline leaf, 4.6–15.0 cm long; pedicels linear, 2.7–9.2 cm long; flowers (1)2–5 per rhipidium, erect, 5–6 cm diameter; tepal blades connivent into a crateriform cup; outer tepals elliptic to elliptic-lanceolate, obtuse at the base, apiculate, 2.2–4.0 × 0.9–1.9 cm; inner tepals with a claw, blade and limb well marked, blade geniculate and involute, limb triangular, acuminate, 1.4–2.4 × 0.3–0.5 cm; tepal colour from pale lavender (violet-blue group 92C) at the base to blue-lavender (violet-blue group 94A and 95C) at apex, the base with blue-lavender macula (violet-blue group 94A and 95C); nectary covered by the folded blade margin; edge of blade bright yellow (yellow group 7A); filaments connate, 0.5–1.1 cm long; anthers divaricate, 0.7–1.0 cm long; ovary clavate, 0.5–0.8 cm long; style branches 0.3–0.7 cm long, bifid into falcate arms with a mucro; mature capsules ellipsoid, 1.0–1.9 × 0.4–0.8 cm; seeds ellipsoid, ca. 0.3 × 0.15 cm.

Distribution, ecology, and phenology:— Tigridia azufresensis grows in few localities in the municipalities of Ciudad Hidalgo and Zinapécuaro, Michoacán ( Fig. 3 ). It inhabits seasonally wet valleys bordered by coniferous forest with Astragalus sp. , Gentiana bicuspidata Briquet (1931: 324) , Platanthera sp. , Sisyrinchium spp. , and Tigridia longispatha (Herb. in Bentham 1839: 53) Goldblatt (2015: 14). The elevation ranges from 2831 to 2960 m. The plants flower from June to August and the fruits mature from September to October.

Conservation status:— Tigridia azufresensis is known in nine localities in Los Azufres, Michoacán. López-Pérez et al. (2022) show that genetically all of them are the same fragmented population. Also, the population is in risk due to cattle grazing, the geothermal power plants, the construction of resorts and hotels, and off-road vehicles driven by tourists. GeoCAT calculated an EOO of 9.623 km 2 and an AOO of 20 km 2. According to the IUCN Red List guidelines and criteria (B1 and B2), we preliminary recommend the Endangered category [EN B1ab(iii)+2 ab(iii)].

Etymology:— The specific epithet refers to the National Park Los Azufres in the Michoacán state. This area is a volcanic caldera in the TVB and Tigridia azufresensis is endemic to this.

Taxonomic comments:— Tigridia azufresensis was first collected in Llano Largo, Michoacán, in July 1987 and since then it was identified as T. durangensis , which is an endemic species of the SMO. Both taxa share morphological characters ( Table 1 ). However, Tigridia azufresensis differs from T. durangensis ( Table 1 ). In general, the plants grow taller and produce larger flowers than T. durangensis . Also, the former develops one rhipidium (vs. one or two); the cauline leaf is plicate (vs. not plicate); the outer tepals are elliptic to elliptic-lanceolate (vs. oblong to oblong-obovate), and the inner tepals have a triangular and apiculate limb (vs. elliptic and acute).

Additional specimens examined ( Tigridia azufresensis paratypes):— MEXICO. Michoacán: municipality of Ciudad Hidalgo: Los Azufres , a 2.5 km al este de Rancho Viejo, 2884 m, 19°47’42.4’’N, 100°38’15.5’’W, 24 July 2020, J. D. López-Pérez 304 ( IBUG!) ; Los Azufres, carretera Toluca-Morelia, Patio de Campamento Deycon Azufres , 2831 m, 19°47’11.3’’N, 100°40’47.5’’W, 24 July 2020, J. D. López-Pérez 308 ( IBUG!) ; Parque Nacional Los Azufres, Unidad 15 CFE, Patio de los Chinos , 2924 m, 19°48’30.7’’N, 100°40’05.9’’W, 14 August 2019, J. D. López-Pérez et al. 235 ( IBUG!) ; Parque Nacional Los Azufres, Unidad 15 CFE, Patio de los Chinos , 2924 m, 19°48’32.3’’N, 100°40’03.3’’W, 24 July 2020, J. D. López-Pérez et al. 302 ( IBUG!) ; municipality of Zinapécuaro: Llano Largo , cerca de Los Azufres, 2900 m, 8 July 1987, H. Díaz-Barriga 3930 (IBUG!, IEB!, MEXU!, UAMIZ!) ; 1 km al E del Cerro del Gallo , 2900 m, 13 September 1989, M. J. Jasso 1124 ( MEXU!) ; Parque Nacional Los Azufres entre el pozo 9 y el pozo 5 de la CFE, 2960 m, 19°48’33.7’’N, 100°39’47.8’’W, 25 August 2002, A. Rodríguez & L. Ortiz-Catedral 3054 ( IBUG!, IEB!) ; Parque Nacional Los Azufres, exactamente en el humedal y desviación a Pozo 9, 4,14,15 y 40, 2944 m, 19°48’32.21’’N, 100°40’1.75’’W, 30 July 2011, G. Munguía-Lino & L. M. Vázquez-García 21 ( IBUG!) ; Parque Los Azufres, pasando la desviación a los pozos 4, 9, 14 y 15, al lado del balneario Los Dragones , 2945 m, 19°48’31.69’’N, 100°40’4.26’’W, 3 August 2013, G. Munguía-Lino & L. M. Vázquez-García 299 ( IBUG!) .

Figures

FIGURE 1. Tigridia azufresensis. A. Habitat. B. Flowering plant. C. Plant with fruits. D. Flower in frontal view. E. Flower in lateral view with cauline leaf and spathe bracts. White arrows= basal leaf, red arrows = cauline leaf.

FIGURE 2. Tigridia azufresensis. A–B. Habit. C. Dissected flower (inner tepal sections: 1 = claw, 2 = blade, 3 = limb, 2 + 3 = lamina). D–E. Flower in frontal and lateral views. F. Style and stamens. G. Seeds. Illustrated by Ericka Belén Cortez Castro based on type material (G. Munguía-Lino et al. 921).

FIGURE 3. Distribution map of endemic species of Tigridia in the Transmexican Volcanic Belt. Biogeographical limit (black line), state limit (thick grey line).