Ceratozamia decumbens Vovides, Avendaño, Pérez-Farr. & Gonz.-Astorga, Novon 18 (1): 110. 2008

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

7. Ceratozamia decumbens Vovides, Avendaño, Pérez-Farr. & Gonz.-Astorga, Novon 18 (1): 110. 2008

Fig. 15G

Type.

Mexico. Veracruz: Naranjal, Near Cueva de Los Munecos , 700 m, 8 Apr 2005, S. Avendaño & G. Alducin 5706 (holotype: XAL! [XAL0005416, XAL0005418]; isotypes: HEM [n.v.], MO!) .

Description.

Stem 10-40 cm long, 10-25 cm in diameter, epigeous, erect and decumbent. Cataphylls 1.5-3 × 2-4.2 cm wide at the base, persistent, triangular, densely tomentose at emergence, reddish brown and partially tomentose at maturity, apex acuminate. Leaves 2-7, 80-190 cm long, descending, reddish brown at emergence with whitish gray trichomes, glabrous at maturity. Petiole 40-100 cm long, terete, linear, greenish brown in mature leaves; with 2-22 (28) thin prickles, 0.02-0.23 cm long. Rachis 40-123 cm long, terete, linear, brown and green in mature leaves, with prickles and occasionally unarmed. Leaflets 8-24 pairs, opposite to subopposite, insertion in one plane, oblong, in general longitudinally planar, not basally falcate, coriaceous, flat, green, adaxial and abaxial sides glabrous, distal end with entire margins, acuminate and symmetrical to asymmetrical at the apex, attenuate at base, with conspicuous and light-green veins; median leaflets 23-47.5 × 2.8-5 cm, 2.6-6.5 cm between leaflets; with articulations 0.7-1.2 cm wide, brown. Pollen strobili 20-23 cm long, 3.8-4.5 cm in diameter, solitary, cylindrical, erect, greenish yellow at emergence with reddish brown trichomes at maturity; peduncle 8-10.8 cm long, 1.2-1.6 cm in diameter, reddish brown to brown pubescent; microsporophylls 1-1.9 × 1-1.4 cm, obconic with a non-recurved distal face and lobate fertile portion, infertile portion 0.59-0.65 cm long and linear with straight horns 0.27-0.33 cm long, 0.67-0.80 cm and an acute angle between the horns. Ovulate strobili 9-11 cm long, 7-8 cm in diameter, solitary, cylindrical, erect, wine at emergence, wine with blackish brown trichomes at maturity, with an acute apex; peduncle 3-4 cm long, 1-1.2 cm in diameter, erect, brown pubescent; megasporophylls 18-49, 6-7 orthostichies with 3-7 sporophylls per orthostichy, 2.3-2.5 × 2-3 cm, with truncate distal face, horns straight and thin and 0.45-0.58 cm long, 0.99-1.48 cm between horns with a right angle between the horns. Seeds 1.2-2 cm long, 1.2-1.5 cm in diameter, ovate, sarcotesta whitish red when immature, light brown at maturity.

Distribution and habitat.

Ceratozamia decumbens is endemic to a small central mountain range in Veracruz State, Mexico (Fig. 16C ) growing on karstic rocks in mountain tropical forest and cloud forest at 450-1,100 m.

Etymology.

The epithet alludes to the decumbent nature of trunks in older mature plants.

Common names.

None recorded.

Uses.

None recorded.

Preliminary conservation status.

Ceratozamia decumbens has not been listed in the IUCN Red List of Threatened Species (https://www.iucnredlist.org/). Its distribution area has been severely affected by anthropogenic land-use changes ( Martínez-Domínguez et al. 2021). However, known populations have between 100 to 150 adult plants with juvenile and seedlings. All data suggest that the conservation status should be "Endangered (EN)".

Discussion.

Ceratozamia decumbens is distinguished from its most similar species ( C. mexicana and C. morettii ) by the ovulate strobili which are are wine red with blackish brown trichomes at maturity and an acute apex, whereas in C. mexicana they are green with blackish brown and gray trichomes with an acuminate apex, and C. morettii are green with with blackish brown trichomes with an apiculate apex. In terms of vegetative morphology, it differs from these species by its reddish brown leaves with whitish gray trichomes at emergence.

Specimens examined.

Mexico. Veracruz: Mun. Atoyac, 900 m, 28 Jan 1986, R. Acevedo R. 728 (XAL). Mun. Coetzala, 650 m, 30 Nov 2001, A. Rincón G. 2798 (MEXU, XAL); 870 m, 15 Jul 2015, L. Martínez-Domínguez et al. 655 - 683 (CIB). Mun. Córdoba, 1,100 m, 10 Jun 1985, A. Espíritu & J.L. Martínez 94 (XAL). Mun. Ixtaczoquitlán, 1,090 m, 25 May 1985, A. Pérez P. 282 (XAL). Mun. Naranjal, 11 Sep 1982, A.P. Vovides 751 (XAL); 10 Oct 1993, Brigada T. Walters s/n (XAL); 11 Sep 1982, J. Rees 1690 (XAL); 10 Oct 1993, T.W. Walters 41277, 41308, 41397 (XAL). Mun. Tequila, 445 m, 28 Oct 2007, J.E. Rivera Hdez. & A. Vergara V. 4195 (MEXU, XAL); 959 m, 15 Jul 2015, F. Nicolalde-Morejón et al. 2259, 2260 (CIB); 959 m, 15 Jul 2015, L. Martínez-Domínguez et al. 684 - 703 (CIB). Mun. Tezonapa, 1 Dec 1995, M.A. García B. 980 (XAL); 475 m, 24 Jun 1986, R. Robles G. 882 (XAL). Mun. Zongolica, 11 Mar 2011, L. Hermann Bojórquez G. et al. 2337 (CIB) .

Figures

Figure 15. Plants of Ceratozamia in habitat A C. alvarezii B C. aurantiaca C C. becerrae D C. brevifrons E C. chamberlainii F C. chimalapensis G C. decumbens H C. delucana I C. euryphyllidia J C. fuscoviridis K C. hondurensis L C. huastecorum.

Figure 16. Distribution of Ceratozamia species A C. chamberlainii B C. chimalapensis C C. decumbens D C. delucana.