Ceratozamia subroseophylla Mart.

Martínez-Domínguez, Lilí, Nicolalde-Morejón, Fernando, Vergara-Silva, Francisco & Stevenson, Dennis W., 2016, Integrative taxonomy of Mexican cycads: biogeography, morphology and DNA barcoding corroborate a new sympatric species in Ceratozamia (Zamiaceae), Phytotaxa 268 (1), pp. 25-45 : 35-37

Ceratozamia subroseophylla Mart. -Domínguez & Nicolalde-Morejón, sp. nov. ( Fig. 4 , 5 )

Ceratozamia subroseophylla is distinguished by its green-brownish petiole and rachis, with abundant prickles; yellowish-brown leaves at emergence; papyraceous leaflets, brown at the base, lanceolate (in adults), symmetrical, non-pruinose on abaxial side, linear to falcate at 1/2 distal leaf portion. Additionally, its ovulate strobilus has a mucronate apex, the distal end of megasporophylls is prominent and green, with a rosaceous base covered by dark brown pubescence.

Type: — MEXICO. Veracruz: Santiago Tuxtla, Sinapan, 425 m, 15 July 2014, L. Martínez-Domínguez 158 ♀ (holotype CIB, isotypes MEXU, NY)

Additional specimens examined (paratypes): — MEXICO. Veracruz, Santiago Tuxtla , Cerro El Vigía, 474 m, 7 March 2014, L. Martínez-Domínguez & F. Nicolalde-Morejón 82, 83, 84, 85, 86, 87, 129 ♀ (CIB) ; L. Martínez-Domínguez & F. Nicolalde-Morejón 78, 79 (NY); L. Martínez-Domínguez & F. Nicolalde-Morejón 80, 81 (XAL); F. Nicolalde-Morejón & L. Martínez-Domínguez 1985, 1986, 1987 (CIB); Sinapan, 425 m, 15 July 2014, L. Martínez-Domínguez 141 ♂, 146 ♂ (CIB). Catemaco, Tatahuicapan de Juárez , 849 m, C. Carvajal-Hernández & M. Juárez F. 796 (CIB) .

Stem epigeous, 10–150 cm, 18–41 cm in diameter. Cataphylls persistent, brown and densely tomentose at emergence, reddish-brown and glabrous at maturity; triangular, apex acuminate, 5–7 × 2.0– 2.5 cm wide at base. Stipules tomentose, reddish-brown, 3.7–4.0 × 0.8–1.2 cm. Leaves 2–83, ascending, 72–272 cm, yellowish-brown at emergence. Petiole terete, 29–104 cm, armed with prickles (except seedlings); greenish-brown or dark brown in new leaves. Rachis terete, 19–188 cm, with prickles (except seedlings). Leaflets 7–40, oblong (young) to lanceolate (adults) symmetric, falcate along distal half, papyraceous, opposite to subopposite, abaxial side pruinose; acuminate and symmetric apex (asymmetrical at early stages), dark green, attenuate at base, with conspicuous veins; median leaflets 18.0–44.5 × 2.5–5.0 cm wide, 1.7–3.9 cm between leaflets; articulations brown (young) or green (adult), 0.6–1.4 cm wide. Pollen strobili solitary, cylindrical, erect, 15 cm; peduncle tomentose, 9.5–10.0 cm, 1.0– 1.2 cm in diameter; microsporophylls 1.8–2.0 × 1.3–1.5 cm. Ovulate strobili solitary, cylindrical, erect, 15.5–23.4 cm, 7.0– 7.8 cm in diameter; apex mucronate, yellow with reddish pubescence at emergence, distal end of megasporophylls green (including horns) at maturity; megasporophylls base pale pink, with dark brown pubescence; peduncle tomentose, light brown, 9.8–17.5 cm, 1.8–2.0 cm in diameter; megasporophylls 128–137, 1.8–2.5 × 2.2–2.8 cm wide, prominent distal face, pubescent. Seeds ovate, cream to light brown, 3.0– 3.8 cm, 0.8–1.0 cm in diameter.

Etymology:— The specific epithet highlights the rosaceous (i.e. pale pink) color at the base of megasporophylls. This character state is present throughout the ontogeny of the ovulate strobilus and has been chosen as an identifying feature in comparisons to any other species in the genus Ceratozamia .

Distribution and habitat:— Only known from Veracruz, Mexico, Ceratozamia subroseophylla is found in the Los Tuxtlas region, an area postulated by Wendt (1987) as a Cenozoic floristic refuge. Biogeographically, this species is distributed from the Sinapan montane zone, in the Santiago Tuxtla municipality, to the San Martín Pajapan volcano zone, in Tatahuicapan de Juárez (between 420−1050 m). Geologically, the montane system of the Los Tuxtlas region ( Fig. 1 ) has a volcanic origin traceable to the Oligocene ( Flores-Delgadillo et al. 1999). Within this, C. subroseophylla occurs in the evergreen tropical rain forest sensu Rzedowski (1978) as part of a relictual vegetation with a high degree of perturbation. In terms of climate, the region is warm humid, with summer rains above 10.2% annual (2,292 mm of precipitation), rains alternate with a dry season (31.1 mm of precipitation) and an average temperature of 24.7 °C ( García 2004).

Figures

FIGURE 1. Distribution map of the species Ceratozamia mexicana, C. brevifrons, C. robusta, C. miqueliana and C. subroseophylla; inset: points A and B corresponding approximately to the Sinapan montane zone and the San Martín Pajapan volcano zone, respectively.

FIGURE 4. Ceratozamia subroseophylla. (4.1) Adult plant with mature leaves; (4.2) adult plant with young leaves; (4.3) Eumaeus sp., defoliator; (4.4) leaflets in median part of leaf; (4.5) detail of rachis and leaflet base; (4.6) new leaf.

FIGURE 5. Ceratozamia subroseophylla. (5.1) Mature ovulate megastrobilus; (5.2) immature ovulate megastrobilus; (5.3) detail of megasporophyll form (incl. color) and megastrobilus apex; (5.4) detail of peduncle and megastrobilus base (incl. color).