Hunzikeria gypsophila Ortiz-Brunel & Díaz-Martínez, 2023

Ortiz-Brunel, Juan Pablo, Díaz-Martínez, Paulina, Ruiz-Sanchez, Eduardo & Rodríguez, Aarón, 2023, A new microendemic species of Hunzikeria (Petunieae, Solanaceae) from the gypsum outcrops of southern Jalisco, Mexico, Phytotaxa 600 (1), pp. 7-15 : 9-10

Hunzikeria gypsophila Ortiz-Brunel & Díaz-Martínez , sp. nov. ( Figs. 1 A–F , 2 C–F , 3 )

TYPE:— MEXICO. Jalisco: Tolimán, Proyecto Yesos del Occidente, Sitio de muestreo 2, Predio La Sierrilla , 19°35’20” N, 103°53’35” W, 870 m, 21 August 2022 (fl, fr), J. P. Ortiz-Brunel & P. Díaz 1677 (holotype: IBUG!, isotypes: MEXU!, ZEA!) .

Hunzikeria gypsophila is a subshrub taller than H. coulteri , H. steyermarkiana , and H. texana (40–60 vs. 15–20 cm), has longer petioles (12–23 vs. 5–12 mm) and wider leaf blades (16–27 vs. 1.5–13 mm), develops longer corolla tubes (35–48 vs. 10–25 mm), and has broader corolla limb diameter (38–52 vs. 15–23 mm).

Subshrubs, 40–60 cm tall, branching from the base; roots fibrous; new stems herbaceous, erect or ascendent, pilose, covered with hyaline glandular trichomes; leaves alternate, petioles 12–23 mm long, blades (20–)27–42 × 16–27 mm, ovate, acute, decurrent, strigulose, reticulate nerved, nerves strigose, margin entire, ciliate with glandular trichomes; flowers solitary, extra-axillary, erect, peduncle 7–17 mm long, glandular tomentose; calyx (7–)9–12 × (6–) 8–13 mm, obconical, densely tomentose, calyx lobes 5, 3–8 mm long, lanceolate, tomentose with glandular trichomes at the margin; corolla light reddish purple, purple when dry, salverform, glandular-pubescent in the external face, corolla tube (35–)39–48 × 1–2 mm, corolla limb diameter 38–52 mm, 5-lobed, all the lobes equal, rounded-obtuse, the mouth strongly constricted around the stamens and the stigma; stamens 4, didynamous, filaments inserted in the tube, two of them reduced, 1.2–1.4 × <0.2 mm, the other two noticeably thickened, 1.5–1.7 × 0.6–0.8 mm, one pair of anthers conspicuously reduced, inserted higher in the tube than the bigger pair, 0.4–0.5 × 0.4–0.6 mm, theca 0.2–0.3 mm wide, the bigger anthers 1.5–2 × 1.4–1.6 mm, theca 0.5–0.6 mm wide, recurved; stigma flattened, winged, cuneate, 3.7–4 × 1.9–2.2 mm, style flattened, 33–40 mm long, ovary globose, up to 2 mm in diameter; capsule included in the calyx, globose, 10 × 6 mm; seeds 2–8, 2 mm in diameter, reniform, pitted, light brown.

Habitat and distribution:— Hunzikeria gypsophila is only known from two ravines separated by 300 linear meters in the same locality. It inhabits partially shaded places within the tropical dry forest between 800 and 900 m of elevation. It grows next to Bursera fagaroides ( Kunth 1825: 27) Engler (1880: 44) , Havardia acatlensis ( Bentham 1875: 593) Britton & Rose (1928: 42) , Hechtia sp. , and Pseudosmodingium perniciosum ( Kunth 1825: 10) Engler (1880: 420) . It grows on gypsum soil with organic material that accumulates when the trees lose their leaves.

Comparison:— Hunzikeria gypsophila presents the typical morphology of the genus but differs from the other species by having noticeable larger structures ( Table 1 ) and by being a subshrub. The plants are at least 20 cm taller than those of any other species. Also, they develop longer petioles, wider leaf blades, longer peduncles, longer corolla tubes, and broader limbs. In H. gypsophila the stigma is flattened and cuneate, while in the other species it is bilobate or cordate. In terms of size, this species is morphologically most similar to Hunzikeria steyermarkiana of Venezuela. However, North American species ( H. coulteri , H. gypsophila , and H. texana ) develop didynamous anthers, while the South American H. steyermarkiana has anthers of equal size. Based on these observations, we could speculate that the North American species are more closely related to each other than to H. steyermarkiana .

Etymology:—The specific epithet refers to the preference of the plants for growing only on gypsum soil.

Phenology:—The plants develop new stems and leaves once the rainy season starts (middle June) and flower from early July to late October. The fruits ripen from September to December. The leaves start to shed once the rainy season ends in late October and some remain until December.

Conservation assessment:— Hunzikeria gypsophila is known from two small ravines in the type locality. The GeoCAT tool estimated an AOO of 4 km 2. In our explorations, we have counted only 17 plants. Access to the location is difficult, and it is possible that more individuals occur in the zone, but more exploration is needed. In addition, the plants are restricted to gypsum soil patches, which are surrounded by more extensive calcareous or even volcanic deposits ( Ortiz-Brunel et al. 2023). According to the IUCN (2022) criteria B and D, it should be considered as Critically Endangered (CR).

Additional specimens examined (paratypes):— MEXICO. Jalisco, Tolimán, Proyecto Yesos del occidente, Sitio de muestreo 2, Predio La Sierrilla , 19°35’20” N, 103°53’35” W, 870 m, 28 July 2022 (fl), J. P. Ortiz-Brunel & E . Ruiz-Sánchez 1618 ( IBUG); Proyecto Yesos del occidente, Predio La Sierrilla , 19°35’20” N, 103°53’45” W, 803 m, 21 August 2022 (fl), J . P . Ortiz-Brunel & P . Díaz 1679 ( IBUG); Proyecto Yesos del occidente, Sitio de muestreo 2, Predio La Sierrilla , 19°35’20” N, 103°53’35” W, 870 m, 18 September 2022 (fl, fr), J . P . Ortiz-Brunel & P . Díaz 1722 ( IBUG); Predio La Sierrilla , 19°35’20” N, 103°53’35” W, 870 m, 21 August 2022 (fl), P . Díaz & J . P . Ortiz-Brunel 18 ( IBUG); Predio La Sierrilla , 19°35’20” N, 103°53’35” W, 870 m, 22 October 2022 (fr), P . Díaz & J . P . Ortiz-Brunel 153 ( IBUG) .

Figures

FIGURE 1. Hunzikeria gypsophila. A. Adult plant. B. Flower. C. Flower and stigma detail. D. Anthers and stigma. E. Capsule. F. Seed. Illustration by Fátima Bracamontes based on the type material (J. P. Ortiz-Brunel & P. Díaz 1677).

FIGURE 2. Mexican Hunzikeria species. A. Hunzikeria coulteri. B. Hunzikeria texana. C–F. Hunzikeria gypsophila. Photographs by Alejandra Martínez-Blancas (A), Miguel González-Botello (B), and Juan Pablo Ortiz-Brunel (C–F).

FIGURE 3. Geographic distribution of Hunzikeria in Mexico. State abbreviations: COAH = Coahuila, HGO = Hidalgo, JAL = Jalisco, NL = Nuevo León, QRO = Querétaro, SLP = San Luis Potosí, TAMPS = Tamaulipas.