Lamourouxia avendanoi Franc. Gut. 2022, sp. nov.
Creators: name: Francisco-Gutiérrez, Antonio
name: Ruiz-Sanchez, Eduardo
name: González, Dolores
name: Lira-Noriega, Andrés
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Lamiales
Orobanchaceae
Lamourouxia
Lamourouxia avendanoi

description: Lamourouxia avendanoi Franc.Gut. sp. nov. (Figs. 1–3 A, C).
Lamourouxia avendanoi belongs to the section Hemispadon and it can be distinguished from the other species by the presence of sessile and elliptic, broadly elliptic to oblong leaves with base rounded, calyx not glandular, and patent lobes of the lower lip of the corolla.
Type:— MEXICO. Nayarit: Nayar [Zacatecas: Valparaíso], 50 km al NE de Jesús María, carr. a Huejuquilla, 2000–2230 m, 13 September 1989, Pedro Tenorio-Lezama & Gabriel Flores-Franco 16022 (holotype MEXU!).
Herbs 40–60 cm tall, stems erect, hirsute with non-glandular trichomes. Leaves opposite, sessile, elliptic, broadly elliptic to oblong, 24–56 × 17–29 mm, margin dentate to crenate, 6–16 teeth per side, 0.5–3.3 mm long, apex acute to obtuse, sometimes short-acuminate, base rounded, lamina membranous and pilose with non-glandular trichomes. Inflorescence ascendent, a raceme, pedicels 0.8–3.3 × 1 mm, one bract per flower. Bracts obovate to ovate, 8–25 × 3–20 mm, apex acute, base rounded, margin dentate, 0–7 teeth per side, each tooth 0.5–2 × 4.3–4.9 mm. Calyx campanulate, 4.3–13 × 3.9–6 mm, pubescent, four-lobed, each lobe triangular, 2.6–7 × 1.1–4.4 mm, apex acute, margin entire, pubescent with non-glandular trichomes. Corolla tubular, 27–54 × 6–10 mm, bilabiate, the upper lip 14–30 mm long, margin not reflexed; lower lip 7–24 × 2 mm, stretched in the middle and the apex three-lobed, each lobe 1.1–3.3 × 0.9 mm, expanded in mature flowers. Stamens exserted, filaments 35–38 mm long, anthers ca. 3.4 mm long, lanose, whitish. Style 37–47 mm long, persistent in fruiting. Stigma capitate, 1–1.4 × 0.9 mm. Fruit a capsule, ovoid, 8.3–9.8 × 5.4–6 mm, glabrous.
Distribution and Ecology:— This species inhabits oak, pine-oak, and tropical deciduous forests at elevations from 1325 to 2280 m a.s.l. The species was photographed by Ana Nuño (https://www.naturalista.mx/observations/83154395) in the municipality of Bolaños, Jalisco, but no specimens from this state were found during the herbaria revision (Fig. 2). Herbarium specimens from the states of Durango, Nayarit, and Zacatecas, Mexico were revised (Fig. 3). The species is distributed near to El Salto area, considered as a hotspot of Mexican endemic angiosperms (Sosa & De-Nova 2012).
Phenology:— Flowers and fruits are recorded from July to October.
Etymology:— The epithet honors Sergio Avendaño-Reyes, a Mexican botanist, and curator of the XAL herbarium from 2009 to 2020. He also has contributed to the knowledge of the flora of Veracruz with taxonomic studies of several families.
Conservation status: — Lamourouxia avendanoi is a range-restricted species, known from eight locations in the Sierra Madre Occidental, Mexico. Its extent of occurrence (EOO) is 15,644.73 km 2, and area of occupancy (AOO) is 32 km 2. Its forest habitat is inferred to be declining due to accelerated deforestation, fragmentation of habitats, and reduction in the forest densities occurred in the last decades (González-Elizondo et al. 2013). The species is listed as Vulnerable species VU B2b(ii,iii).
Most specimens are distributed within the Cuenca Alimentadora del Distrito Nacional de Riego 043 Estado de Nayarit, a Natural Resources Protection Area that covers the states of Aguascalientes, Jalisco, Durango, Nayarit, and Zacatecas, Mexico (Fig. 4).
Discussion:—Specimens of Lamourouxia avendanoi were determined as belonging to L. viscosa Kunth (1818: 338), the species most variable morphologically in the genus and one of the few species distributed in the northern states of Mexico. The confusion arises by the similitude of the toothed leaves. The leaves of L. avendanoi are elliptic to broadly elliptic, while the leaves of L. viscosa are broadly or narrowly ovate to elliptical or lanceolate, but the absence of glandular trichomes in the calyx is a feature not shared with L. viscosa. The key presented by Ernst (1972) refers to L. smithii Robinson & Greenman (1895: 172) as the only species in section Hemispadon with calyx not glandular and sessile leaves ovate. The notably different shape of the leaves regarding L. smithii, and other characters are presented in Table 2. Geographically, the species are isolated from each other. Lamourouxia avendanoi is distributed in the western states of Durango, Jalisco, and Nayarit. In contrast, L. smithii was reported as endemic to the southern state of Oaxaca.
Additional specimens examined (Paratypes):— MEXICO. Durango: Pueblo Nuevo, La Yerbabuena, comunidad San Bernardino de Milpillas, 2280 m, 26 September 1981, Pérez 797 (ENCB!); Mezquital, Aprox. 4 km de La Guajolota, 11 September 1985, Solís 257 (CIIDIR!, MEXU!); El Salto, Pie de Cuesta 4 km al S de Pueblo Nuevo, 1860 m, 02 July 1984, Tenorio et al. 6169 (MEXU!); Toyaltita, Carboneras 54 Km al SW de San Miguel de Cruces, brecha a Toyaltita, 1800 m, 06 July 1984, Tenorio et al. 6246 (MEXU!). Zacatecas: [Valparaíso], 31 km al NE de Jesús María, camino Jesús María-Huejuquilla, 1430 m, 27 July 1990, Flores-Franco et al. 2103 (MEXU!). Nayarit: El Nayar, Arroyo de La Taberna northwest of Mesa del Nayar, 1325 m, 13 August 1980, Breedlove & Almeda 45556 (MEXU!).
description: Published as part of Francisco-Gutiérrez, Antonio, Ruiz-Sanchez, Eduardo, González, Dolores & Lira-Noriega, Andrés, 2022, Two new species of Lamourouxia section Hemispadon (Orobanchaceae) from western Mexico, pp. 51-66 in Phytotaxa 549 (1) on pages 54-58, DOI: 10.11646/phytotaxa.549.1.4, http://zenodo.org/record/6605334