Ceratozamia chamberlainii Mart.

Martínez-Domínguez, Lilí, Nicolalde-Morejón, Fernando & Stevenson, Dennis Wm., 2017, Qualitative and quantitative morphological evidence for recognition of a new species within Ceratozamia (Zamiaceae) from Mexico, Phytotaxa 317 (1), pp. 17-28 : 22-23

Ceratozamia chamberlainii Mart. -Domínguez, Nic.-Mor. & D.W. Stev., sp. nov. ( Figs. 2 , 5 )

Ceratozamia chamberlainii is distinguished by its petioles and rachis with abundant and short prickles; reddish-brown leaves at emergence with the color on articulation, petiole and margin in adult leaves; oblong leaflets, mostly planar and abaxially curved at 1/2 distal leaf portion, not basally falcate, coriaceous, asymmetric apex, conspicuous and reddish-brown veins; median leaflets, 20–37 × 2.3–3.5 cm wide, 1.6–3.5 cm between leaflets. Additionally, its ovulate strobilus has an acuminate apex, is light grayish brown with red trichomes, and megasporophylls are green.

Type:— MEXICO. San Luis Potosí: Xilitla, La Ceiba, 850 m, 20 March 2016, L. Martínez-Domínguez, F. Nicolalde-Morejón & Q. Santiago-Jiménez 933 ♀ (holotype: CIB; isotypes: MEXU, NY)

Additional Specimens Examined:— MEXICO. Querétaro, Landa de Matamoros, near Agua Zarca , 30 March 2015, L. Martínez-Domínguez et al. 379, 405 ♂ ( CIB), 380–404 ( CIB), F. Nicolalde-Morejón et al. 2192–2197 ( CIB) ; Landa de Matamoros, El Camarón, 30 March 2015, L. Martínez-Domínguez et al. 408–426 ( CIB), 427– 428 ♂ ( CIB), F. Nicolalde-Morejón et al. 2198, 2199 ( CIB) ; Landa de Matamoros, Humo-Neblinas , 28 May 1999, V ovides 1291 ( XAL, MEXU), 1288, 1290 ( XAL) ; 2 April 1991, E. Carranza 3119 ( MEXU). Hidalgo, Chapulhuacán, Puerto El Zopilote, 30 March 2015, L. Martínez-Domínguez et al. 429–430 ( CIB), 441– 443 ♀ ( CIB), 447 ♂ ( CIB), F. Nicolalde-Morejón et al. 2200–2203 ( CIB) ; Chapulhuacán, Cerro Los Jarros, 21 February 1998, Alcántara-Ayala 3650 ( FCME) ; La Misión, Loma de Pericón, 7 January 2009, Vite-Reyes et al. 20 ( XAL) ; Puerto Naranjos, 5 October 2007, Castro- Castro et al. 1017 ( XAL). San Luis Potosí, Xilitla , La Ceiba , 20 March 2016, L. Martínez-Domínguez et al. 924–932 ( CIB), F. Nicolalde-Morejón et al. 2407-2420 ( CIB) ; Xilitla, 13.5 Km W, 12 January 2001, T. W. Walters, 2001-04- A ( XAL) .

Stem epigeous, 20–60 cm tall, 15–30 cm in diameter. Cataphylls persistent, densely tomentose at emergence, reddish-brown and glabrous at maturity; triangular, apex acuminate, 2.5–5.5 × 1.5–3.5 cm wide at base. Stipules tomentose, reddish-brown, 2.0–3 × 0.5–1 cm. Leaves 5–40, descending, 100–207 cm, reddish-brown at emergence, glabrous. Petiole terete, 30–69 cm, armed with short and robust prickles, blackish-brown in adult leaves. Rachis terete, 65–144 cm, armed with prickles, reddish-brown in adult leaves. Leaflets 20–42, oblong, mostly planar and abaxially curved, not basally falcate, coriaceous, opposite to subopposite, dark-green, adaxial and abaxial sides glabrous, acuminate and asymmetric apex, attenuate at base, with conspicuous and reddish-brown veins; median leaflets 20–37 × 2.3–4 cm wide, 1.6–3.5 cm between leaflets; articulations generally reddish-brown, 0.5–1.3 cm wide. Pollen strobilus 1–2, cylindrical, erect, 26–31 cm, 4.8–6 cm in diameter, greenish brown at emergence, greenish yellow with brown pubescence at maturity; peduncle tomentose, reddish-brown, 6–10.3 cm, 1.6–2 cm in diameter; microsporophylls 1.6–2.3 × 1.1–1.5 cm wide. Ovulate strobilus solitary, cylindrical, erect, 28–30 cm, 9–10.5 cm in diameter, greyish green with reddish-brown pubescence at emergence, light grayish brown with reddish-brown trichomes at maturity, acuminate apex; peduncle tomentose, brown to reddish-brown, 4.5–11 cm, 1.3–2.5 cm in diameter; megasporophylls 72–190, 1.5–2.5 × 2.3–3.0 cm wide, distal face prominent. Seeds ovate, sarcotesta whitish pink to pink when immature, light brown at maturity, 3.0–4.0 cm, 0.6–1.2 cm in diameter.

Etymology:— The specific epithet has been chosen to honor Charles Joseph Chamberlain, in recognition of his outstanding contributions to the knowledge of the biology of the cycads and his fieldwork on Mexican cycads.

Distribution and habitat:— Biogeographically, this species is distributed from the northern montane region of Carso Huasteco, in San Luis Potosí, Querétaro and Hidalgo ( Fig. 4 ). It occurs in pine-oak forest ( Rzedowski 1978, Luna-Vega & Alcántara-Ayala 2004), on rocky outcrops of exposed walls, within the elevational range of 900– 1, 200 m.

Figures

FIGURE 2. Ceratozamia chamberlainii. (2.1) Adult plant with mature leaves; (2.2) microsporophyll; (2.3) new leaf; (2.4) detail of rachis and leaflet base; (2.5) pollen strobilus; (2.6) ovulate strobilus at emergence; (2.7) ovulate strobilus; (2.8) ovulate strobilus at maturity.

FIGURE 4. Distribution map of the species Ceratozamia chamberlainii and C. fuscoviridis; species records obtained from herbaria are represented by small solid black figures and sampled populations for this study with large figures.

FIGURE 5. Ceratozamia chamberlainii. (5.1) Pollen strobilus at maturity; (5.2) leaf; (5.3) detail of leaflet; (5.4) seeds; (5.5) megasporophylls; (5.6) ovulate strobilus at maturity.