Ceratozamia reesii Vovides, Pérez-Farrera and Gutiérrez-Ortega, 2022

Vovides, Andrew P., Pérez-Farrera, Miguel Angel, Salinasrodríguez, María Magdalena, Galicia, Sonia, Díaz-Jiménez, Pedro, Calonje, Michael & Gutiérrez-Ortega, José Said, 2022, Morphological and anatomical analyses clarify the species definition of Ceratozamia latifolia Miq. (Zamiaceae) and lead to the description of a new species: Ceratozamia reesii, Phytotaxa 575 (3), pp. 224-252 : 241

Ceratozamia reesii Vovides, Pérez-Farrera and Gutiérrez-Ortega sp. nov. ( Fig. 14–17 )

Ceratozamia reesii can be distinguished from other species in the genus by having 4–12 leaves per crown, light green color in emerging leaves, petioles armed with thin prickles, leaflets coriaceous, elliptic to lanceolate or oblanceolate, 11–23 pairs. Megastrobilus solitary erect, brown, peduncle 4.2–6 cm long. Seed 2–2.8 cm long.

Holotype. MEXICO, San Luis Potosí: Xilitla, Camino a San Pedro Huiztquilico , 790 m a.s.l., 31 July 2021, M.A. Pérez-Farrera, P. Díaz, & M.M. Salinas 4017 ♀ (HEM). Isotype: XAL.

Plant rupicolous, unbranching, stem short, cylindrical, erect, covered with persistent leaf bases, 12–33 cm tall, 10.5–17 cm in diameter. Cataphylls persistent, brown and densely tomentose at emergence, triangular apex acuminate. Leaves pinnate, 4–12 per crown, forming a semi-open crown, erect, ascending, olive green, 69.5–201 cm long, 39.6–71 cm wide, light green color at emergence, turning olive green at maturity. Petiole terete, 34–67.8 cm long, armed with thin prickles. Rachis green, terete, 34.5–138 cm long, erect, with sparse prickles diminishing into the distal end of the rachis. Leaflets 11–23 pairs, linear, long oblanceolate or oblanceolate, coriaceous, alternate to sub-alternate in the basal part of the leaf, subopposite in the median part, opposite in the apical part, subfalcate into apical part of leaflet, margin entire, apex acute to acuminate, asymmetric; base broad attenuate, articulation yellow adaxially, light green abaxially, 0.4–1.3 cm wide, veins 28–37, parallel, inconspicuous; median leaflets 19.8–35.5 cm long, 1.5– 5.1 cm wide, spaced 1.2–7.2 cm between leaflets. Microstrobilus solitary, conical, erect, light brown when mature, 33–35 cm long, 4.8–5 cm diameter, peduncle densely tomentose, light brown, 14–15 cm long, 1.5–1.8 cm diameter. Microsporophyll cuneiform, 10.11–12.59 mm long, 4.69–6.25 mm wide, distal face bicornate, with light brown color at the central portion, sporangia zone on abaxial surface 4.10–7.65 mm long, microsporangia grouped in 3–4 per sorus. Megastrobilus solitary, cylindrical, erect, 16–16.3 cm long, 6.5–8 cm diameter; apex mucronate, brown pubescent at mature, peduncle short, brown, tomentose, 4.2–6 cm long, 1.06–1.56 cm in diameter. Megasporophylls peltate, bicornate, 3.7–4.2 cm wide, 1.5–2.1 cm tall, distal face pubescent, when mature, distal face presents a light brown to brown color at the central portion, which fades to brown-reddish towards the margins. Seed ovoid, sarcotesta cream when immature, sclerotesta beige when mature, 1.45–1.67 cm diameter, 2.0– 2.28 cm long, with micropylar ridges.

Specimens examined: MEXICO. San Luis Potosí: Xilitla, Las Pozas, Jardín Escultórico Edward James , 665 m, 24 April 2018, M.A. Pérez-Farrera 4021 ( HEM) ; Xilitla, El Cañón , 580 m, 30 July 2021, M.A. Pérez-Farrera, P. Díaz, & M.M. Salinas 4016 ( HEM) ; Xilitla, Cerro de la Silleta , 1300 m, 20 July 2021, M.M. Salinas s.n. ( QMEX) ; Cultivated at Jardín Botánico Francisco Javier Clavijero (Veracruz), accession 2001-110A, originally collected by S. Avendaño 5304 at Cerro del Muerto , Xilitla, 25 August 2014, A.P. Vovides 1522 ( XAL) .

Etymology: The specific epithet was chosen to honor the memory of John David Rees (1932–2021), an American botanist and a mentor on cycads to the principal author. His guidance and knowledge on Mexican cycads were invaluable to the later creation of the Mexican National Cycad Collection of the Francisco Javier Clavijero Botanic Garden of INECOL, Xalapa, Veracruz.

Figures

FIGURE 14. Ceratozamia reesii sp. nov. in the holotype’s population, San Pedro, Xilitla, SLP. (A) Adult plant in its usual karstic cliff habitat. Aspect of leaves in (B) juveniles and (C) and adult plants in habitat.

FIGURE 15. Ceratozamia reesii sp. nov. in El Cañón, Xilitla, SLP. (A) Adult plant with emerging leaves. Note that emerging leaves are light green, differing with the reddish-brown of the closely related species C. chamberlainii. (B–C) Details of leaflet shape. Photos by Diego Báez Ruiz.

FIGURE 16. Ceratozamia reesii sp. nov. Pollen cone (A), seed cone (B), (C) details of the leaflet articulations, (D) prickles in petiole. Scales = 10 cm. Photos A and B edited by José García. Photo D by Diego Báez Ruiz.

FIGURE 17. Ceratozamia reesii sp. nov. plant in its usual karstic cliff habitat in El Cañón, Xilitla, SLP.