Ceratozamia zaragozae Medellin-Leal , Brittonia 15: 175. 1963

Martinez-Dominguez, Lili, Nicolalde-Morejon, Fernando, Vergara-Silva, Francisco & Stevenson, Dennis Wm., 2022, Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus, PhytoKeys 208, pp. 1-102 : 1

35. Ceratozamia zaragozae Medellin-Leal, Brittonia 15: 175. 1963

Fig. 27I

Type.

Mexico. San Luis Potosí: Mun. Rio Verde , 22 Jul 1962, F. Medellín-Leal 1452 ♀ (holotype: SLPM! [acc. # 003530]; isotypes: ENCB! [ENCB003716], GH! [00003279], MEXU! [MEXU00162859, MEXU0053418], MICH! [1192896], US! [00011997]).

Description.

Stem 10-20 cm long, 10-15 cm in diameter, semi-hypogeous, erect. Cataphylls 1.8-2.5 × 1-2 cm wide at the base, persistent, triangular, reddish brown, densely brown tomentose at emergence, partially tomentose at maturity, apex acuminate. Leaves 3-27, 95-202 cm long, ascending, reddish brown at emergence with whitish gray trichomes, glabrous at maturity. Petiole 11-36 cm long, terete, twisted, green in mature leaves, unarmed. Rachis 40-77 cm long, terete, twisted, green in mature leaves, unarmed. Leaflets 25-46, opposite to subopposite, insertion in one plane, linear, generally longitudinally planar, basally falcate, membranaceous, strongly involute, green with adaxial and abaxial sides glabrous, distal end with entire margins, acute and symmetrical at the apex, attenuate at base, with conspicuous and light-green veins; median leaflets 17-31.5 × 0.4-0.7 cm, 0.8-2.3 cm between leaflets; articulations 0.2-0.3 cm wide, yellow. Pollen strobili 15-19 cm long, 2-3.5 cm in diameter, solitary, cylindrical, erect, greenish with reddish brown trichomes at emergence, reddish brown at maturity; peduncle 5-8 cm long, 1.5-1.8 cm in diameter, tomentose, reddish brown to brown; microsporophylls 0.8-1.2 × 0.3-0.6 cm, obconic with a non-recurved distal face and a lobate fertile portion, infertile portion 0.25-0.35 cm long and rounded with straight horns 0.20-0.30 cm long, 0.22-0.30 cm and an obtuse angle between the horns. Ovulate strobili 7-12 cm long, 5.5-7.3 cm in diameter, solitary, cylindrical, erect, green with scarce reddish brown trichomes at emergence, dark green at maturity, acute apex; peduncle 6-9 cm long, 0.9-1.2 cm in diameter, erect, tomentose, brown; megasporophylls 24-49, 5-7 orthostichies with 5-6 sporophylls per orthostichy, 2.0-2.6 × 2.2-3.7 cm, with a truncate distal face, horns straight and 0.33-0.45 cm long, 1.95-2.35 cm between horns with an obtuse angle between the horns. Seeds 2-2.8 cm long, 1.8-2 cm in diameter, ovate, sarcotesta light brown at maturity.

Distribution and habitat.

Ceratozamia zaragozae is endemic to Mexico in a small mountain range in San Luis Potosí (Fig. 29C ), where it occurs in pine-oak forest on karstic rocks at 1,500-1,950 m.

Etymology.

The specific epithet refers to General Ignacio Zaragoza, who was a hero in the Battle of Puebla against the French Army in May of 1862.

Common names.

None recorded.

Uses.

None recorded.

Conservation status.

( IUCN 2021). Ceratozamia zaragozae is listed as "Critically Endangered (CR)" under criteria A2acd; B1ab(iii,iv,v)+2ab(iii,iv,v); C1. Castillo-Lara et al. (2018) evaluated the population structure and spatial distribution for this species and found that the populations have several individuals with a density variable from four to 209 plants in an area of 2500 m2, but low population growth. These authors suggest that the status for this species could be modified to "Endangered (EN)".

Discussion.

Ceratozamia zaragozae and C. norstogii are the only species in the genus with twisted petiole and rachis, but the first has an unarmed petiole, whereas C. norstogii has abundant and robust prickles on the petiole. Additionally, leaflets are membranaceous in C. zaragozae , whereas in C. norstogii they are coriaceous.

Specimens examined.

Mexico. San Luis Potosí: Mun. Río Verde , 1,700 m, 29 Mar 1984, A.G. Mendoza & L. Vargas 1389 (MEXU); 1,750 m, 20 Sep 1979, A.P. Vovides 435 (XAL); 22 Jul 1962, E. Molseed 34 (MEXU; MICH); 1,860 m, 24 Jan 1994, F. García S. s/n (SLPM); 1,800 m, 22 Jul 1962, F. Medellin-Leal 1451 (SLPM; US) ; 28 Oct 1965, F. Medellin-Leal s/n (SLPM); 1,900 m, Sep 1994, F. Medellin-Leal s/n (SLPM); 1,956 m, 18 Mar 2016, F. Nicolalde-Morejón et al. 2307 - 2319 (CIB); 1,750 m, 13 Apr 1968, J. Rzedowski 25658 (ENCB; MICH); 1,956 m, 18 Mar 2016, L. Martínez-Domínguez et al. 792, 794-796, 798-808 (CIB), 793, 797, 799 (CIB, MEXU); 2031 m, 31 Jul 2017, P. Chávez C. et al. 98 (SLPM); 1,532 m, 13 Jan 2001, T. Walters et al. TW-2001-07 (MEXU, XAL). Mun. Zaragoza, 1,869 m, 9 Nov 2012, P. Castillo-Lara et al. 593 (SLPM); 1,847 m, 14 Jul 2016, P. Castillo-Lara et al. 1073 (SLPM).

Figures

Figure 27. Plants of Ceratozamia in habitat. A C. norstogii B C. oliversacksii C C. robusta D C. sabatoi E C. santillanii F C. tenuis G C. totonacorum H C. vovidesii I C. zaragozae.

Figure 29. Distribution of Ceratozamia species A C. vovidesii B C. whitelockiana C C. zaragozae D C. zoquorum.