Anthurium tiswatl Díaz Jim. & Croat, 2024

Jiménez, Pedro Díaz, Croat, Thomas B., Amith, Jonathan D., Pérez-Farrera, Miguel Ángel & Aguilar-Rodríguez, Pedro A., 2024, A new species of broad-leafed Anthurium (Araceae) from the central region of Veracruz, Mexico, Phytotaxa 644 (1), pp. 63-68 : 64-66

Anthurium tiswatl Díaz Jim. & Croat , sp. nov. ( Fig. 1 )

Anthurium tiswatl Diaz Jim. & Croat is similar to A. macdougallii Matuda (1951: 373–374) , but differs from that species in having longer cataphylls (11–16 vs. 5.5–7.0 cm in A. macdougallii ), longer blades (44–65 vs. 18–33 cm), collective veins arising from first or fifth pairs of basal veins (vs. collective veins arising from the fourth or sixth pairs of basal veins), and yellowish and whitish berries when ripe (vs. orange). It can also be confused with A. andicola Liebmann (1849: 22) , but A. tiswatl differs in having leaf blades with a greater number of basal lateral veins (7–9 vs. 3–6), yellowish-green or light green spathe at anthesis (vs. dark purple to brown), and yellowish and whitish berries when ripe (vs. light violet and white).

Type: — MEXICO. Veracruz: Municipio Tequila, Tlaxacapitzco , Tecuanca , 18°44’09”N, 97°03’56”W, 1804 m, 6 April 2022, Pedro Díaz Jiménez & Gabriela Citlahua Zepahua 1674 (holotype: XAL!, isotypes: HEM!, MO!) .

Terrestrial or epipetric; stem thick, up to 16 cm long and 7–8 cm in diam.; leaf scars 3–4 cm wide; roots thick, 2.8–5.0 mm in diam.; cataphylls subcoriaceous, 11–16 cm long, light green, acuminate at apex, drying light brown, weathering to a fibrous network at the base, persisting. Leaves erect; petioles erect, 48–72 cm long, 10.0– 19.5 mm diam., broadly sulcate with acute margins or flattened adaxially, light green or brown-reddish, drying dark brown; geniculum 3.0– 3.1 cm long, 17.5–20 mm diam., flattened or sulcate adaxially, green or reddish; blades widely ovate to ovate-triangular, coriaceous, acute or rounded at apex, sometimes with an apiculum up to 5 mm long, deeply and broadly lobed at base, 44–65 cm long, 36–56 cm wide, broadest at point of petiole attachment; anterior lobe 30–48 cm long, the margins broadly rounded and ± undulate; posterior lobes 16–20 cm long, 13–25 cm wide, rounded at apex, often directed outward; sinus parabolic or ± birettiform, rounded at apex; the upper surface glossy dark green, the lower surface semiglossy light green, drying matte green or brown semiglossy on both surfaces; midrib raised above, diminished and flat at apex, raised below, dark green or yellowish-green above and light green or yellowish below; basal veins 7–9 pairs, the first or second free to base, the second to the third coalesced to 2.5 cm, third to the fourth of 1.5–4 cm and fourth to remaining of 4–7 cm; posterior ribs naked; primary lateral veins 5–7 per side, departing midrib at 20–35° angle, slightly raised above, raised below, yellowish-green above and light green or yellowish below, tertiary venation visible on both sides, prominently raised below; collective veins arising from first or fifth pair of basal veins, sunken above, raised below, 4.5–24.0 mm from margin. Inflorescence erect, shorter than leaves; peduncle thick, 40–54 cm long, 8–11 mm diam., terete, dark green or brown-reddish; spathe erect, lanceolate, coriaceous, yellowish-green or light green, and tinged at margins with purple, up to 11 cm long, 4.5 cm wide, acuminate at apex, subcordate at the base, inserted at 50–60° angle on peduncle, short stipe; spadix tapered, dark purple at anthesis, up to 14.8 cm long, 17 mm diam. at the base, 7 mm diam. at the apex, with 6–7 flowers visible in the principal spiral, 8–9 flowers visible in the alternate spiral, flowers rhombic, 2.0– 4.1 mm wide, 2.6–4.5 long, the sides weakly sigmoid; tepals greenish or dark, minutely papillate, the lateral tepals 1.2–2.6 mm wide, the inner margin ± straight; pistils weakly emergent, 1–1.5 mm long, dark, stigma oblong to linear. Infructescence pendent; spadix up to 17 cm long, 28 mm diam., tepals brown or light brown; immature berries green or yellowish-green when immature, yellowish and whitish when ripe, obovoid, ± round at apex, 7.2–12.0 mm long, 6–9 mm wide; seeds 1 or 2, oblong, greenish to whitish, 5.5–10.0 mm long, 3.5–6 mm diam.

Distribution, habitat and phenology: — Anthurium tiswatl is endemic to the municipality of Tequila ( Fig. 2 ), Veracruz, Mexico, in the central region of the state, at 1800–1900 m, in pine-oak forest. It grows in the understory, on the edges of the forest, or in forest fragments. In the vicinity, Anthurium tiswatl may be found in the municipalities of Atlahuilco, Ixtaczoquitlán, Los Reyes, Magdalena, Omealca, Orizaba, San Andrés Tenejapan and Zongolica. All specimens with inflorescences and infructescence were collected in April.

Eponymy: —This species is named for the local name as it is known in its type locality, named as such because of its morphological traits and habitat. The term “tiswatl ” is the local, central Veracruz variant pronunciation of “teswatl”, a plant name documented in sources from the mid-16th century (e.g., Hernández 1959) and widely used in Nahuatl-speaking communities in the northeastern Sierra de Puebla for several Araceae and Melastomataceae alike. An explanation for the local use of the term “tiswatl ” for an Anthurium might be related to the etymology of this term: ti- ‘rock’ or ‘stone’ and iswatl ‘broad leaf’ such as that found in maize plants and many other monocots. The Anthurium here described is broad-leafed and is often found in rocky soil, hence the incorporated element ti-.

Preliminary conservation status: —Applying the IUCN Red List Categories and Criteria and considering the area where the two populations of Anthurium tiswatl were found, in an area of about 2 km 2 and on private property, with fragments of cleared forest, this species could be considered as Critically Endangered ([CR B2ab(ii,iii,iv,v)]) ( IUCN 2012), but further studies are needed, since the species could be found in a larger area in the central region of Veracruz.

Additional specimen examined (paratype):— MEXICO. Veracruz: Mun. Tequila, Tlaxacapitzco, Tecuanca, 18°44’12”N, 97°03’54”W, 1809 m, 6 April 2022, Pedro Díaz Jiménez & Gabriela Citlahua Zepahua 1673 (HEM!).

Figures

FIGURE 1. Anthurium tiswatl. A. Adult plant in its habit; B. Adaxial view of the leaf blade with a portion of the petiole; C. Inflorescence at anthesis (male phase) showing yellowish-green spathe, tinged with purple on the margins; D. Infructescence showing yellowish-green immature berries. Photos by P. Díaz Jiménez.

FIGURE 2. Map showing the collection site (black dot) of Anthurium tiswatl sp. nov. in Tequila, Veracruz, Mexico.