Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus Author Martinez-Dominguez, Lili https://orcid.org/0000-0003-1158-1501 Posgrado en Ciencias Biologicas, Instituto de Biologia, Universidad Nacional Autonoma de Mexico, 3 er. Circuito Exterior, Ciudad Universitaria, 04510, Coyoacan, CDMX, Mexico lilimartinezd@gmail.com Author Nicolalde-Morejon, Fernando https://orcid.org/0000-0003-1423-7474 Laboratorio de Teoria Evolutiva e Historia de la Ciencia, Instituto de Biologia, Universidad Nacional Autonoma de Mexico, 3 er. Circuito Exterior, Ciudad Universitaria, 04510, Coyoacan, CDMX. Mexico Author Vergara-Silva, Francisco https://orcid.org/0000-0001-5024-268X Posgrado en Ciencias Biologicas, Instituto de Biologia, Universidad Nacional Autonoma de Mexico, 3 er. Circuito Exterior, Ciudad Universitaria, 04510, Coyoacan, CDMX, Mexico Author Stevenson, Dennis Wm. https://orcid.org/0000-0002-2986-7076 Laboratorio de Taxonomia Integrativa, Instituto de Investigaciones Biologicas, Universidad Veracruzana, Xalapa, 91190, Veracruz. Mexico dws@nybg.org text PhytoKeys 2022 2022-09-21 208 1 102 http://dx.doi.org/10.3897/phytokeys.208.80382 journal article http://dx.doi.org/10.3897/phytokeys.208.80382 1314-2003-208-1 F47A23EA345757E29C2800F6D51CEE05 31. Ceratozamia tenuis (Dyer) D.W.Stev. & Vovides, Bot. Sci. 94 (2): 425. 2016 Fig. 27F Ceratozamia tenuis Type. Cultivated in England at the Royal Botanic Gardens Kew "Hort. Kew Palm House", 1881, Anon. s.n. (lectotype, designated by Vovides et al. 2016 , pg. 425: K! [K001092673, K001092674]). Mexico. Veracruz: Mun. Jilotepec, 19 Jan 1976, A.P. Vovides 18 ♂ (epitype, designated by Martinez-Dominguez et al. 2018a , 117: XAL! [acc. # 16980]; isoepitype: NY!). Ceratozamia mexicana Brongn. var. vulgaris J.Schust., Pflanzenr. (Engler) Heft 99, 4 fam 1: 131. 1932. Mexico. Veracruz: Mun. Xalapa, Chiltoyac, 1,270 m, 18 Oct 2016, L. Martínez-Domínguez et al. 984 (neotype, designated by Martinez-Dominguez et al. 2018a , pg. 117: CIB! [acc. # 17988UV]). Ceratozamia mexicana f. tenuis (Dyer) J.Schust., Pflanzenr. (Engler) Heft 99, 4 fam 1: 132. 1932, as " Ceratozamia mexicana var. longifolia f. tenuis ". Type: Based on Ceratozamia mexicana Brongn. var. tenuis Dyer Type . Based on Ceratozamia mexicana Brongn. var. tenuis Dyer, Biol. Cent.-Amer., Bot. 3: 193. 1884. Description. Stem 20-100 cm long, 30-45 cm in diameter, epigeous, erect and decumbent. Cataphylls 2-6 x 2-5.5 cm wide at the base, persistent, triangular, reddish brown, densely brown tomentose at emergence, partially tomentose at maturity, apex acuminate. Leaves 6-56, 85-225 cm long, ascending, dark green at emergence with brown trichomes, glabrous at maturity. Petiole 30-93 cm long, terete, linear, green in mature leaves; with 10-55 thin prickles, 0.20-0.49 cm long. Rachis 56-154 cm long, terete, linear, green in mature leaves, with prickles. Leaflets 30-56 pairs, opposite to subopposite, insertion in one plane, linear, longitudinally curved abaxially to planar, basally falcate, papyraceous, involute, green with adaxial and abaxial sides glabrous, distal end with entire margins, acuminate and symmetrical at apex, attenuate at base, with conspicuous and light-green veins; median leaflets 23-50.5 x 1-2.1 cm, 0.3-2.5 cm between leaflets; articulations 0.4-1.4 cm wide, green. Pollen strobili 25-50 cm long, 4-8 cm in diameter, solitary, cylindrical, erect, greenish yellow at emergence, greenish yellow with blackish trichomes at maturity; peduncle 3.7-22 cm long, 1.2-2.5 cm in diameter, tomentose, reddish brown to light-brown; microsporophylls 1.7-2.7 x 1.2-1.9 cm, obconic with a non-recurved distal face and a lobate fertile portion, infertile portion 0.50-0.65 cm long and orbicular with recurved horns 0.25-0.46 cm long, 0.35-0.65 cm between the horns and a right angle between the horns. Ovulate strobili 22-35 cm long, (7.6) 10-14 cm in diameter, solitary, cylindrical, erect, dark green with blackish trichomes at emergence, dark green with blackish trichomes at maturity, acuminate apex; peduncle 8-23 cm long, 1.5-2.4 cm in diameter, erect or pendulous, tomentose, brown to reddish brown; megasporophylls (48) 80-196, 7-16 orthostichies with 6-14 sporophylls per orthostichy, 2.1-3.1 x 3.0-5.0 cm, with a prominent distal face, horns curved and 0.32-0.80 cm long, 0.80-1.60 cm between horns with a right angle between the horns. Seeds 2.5-3 cm long, 1.3-1.8 cm in diameter, ovate, sarcotesta whitish yellow to yellow when immature, light brown at maturity. Distribution and habitat. Ceratozamia tenuis is endemic to the central montane region in Veracruz State, Mexico (Fig. 24C ), where it occurs in cloud forest at 1,200-1,920 m elevation on volcanic soils with basaltic rocks. Etymology. The specific epithet is derived from its thin leaflets. Common names. Mexico. Veracruz: Costilla de leon (L. Martinez-Dominguez et al. 573); palma del monte (L. Martinez-Dominguez et al. 166). Uses. Ovulate strobili are used as an insecticide; these are cut in half and mixed with milk or sugar to kill flies (L. Martinez-Dominguez et al. 980). Conservation status. Ceratozamia tenuis has not been assessed for The IUCN Red List of Threatened Species. This species has populations with several adult plants (between 100 to 300); however, the total area of distribution is narrow and it is one of the areas that is highly affected by changes in land use in recent years. According to IUCN criteria this species should be considered as "Endangered" (EN) under A1acd; B1ab(iii). 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 . Discussion. Ceratozamia tenuis is characterized by a petiole with thin prickles, and linear leaflets that are papyraceous and involute with a symmetric apex. The ovulate strobilus is dark green with blackish trichomes at maturity, a prominent distal face, and a right angle between the horns. Specimens examined. Mexico . Veracruz : Mun. Banderilla , 1,450 m , 21 Apr 2017 , L. Martinez-Dominguez et al. 1000 (CIB). Mun. Chiconquiaco , 1,800 m , 26 Nov 1974 , D. Jimeno-Sevilla 754 (XAL); 1,916 m , 27 Sep 2016 , F. Nicolalde-Morejon et al. 2456 - 2464 (CIB); 1,800 m , 26 Nov 1974 , J. Rees 1625 (XAL), 1626 (MEXU, XAL); 1,916 m , 27 Sep 2016 , L. Martinez-Dominguez et al. 971, 973 - 981 (CIB), 972 (CIB, MEXU); 13 Apr 1967 , R. Fernandez-Nava 385A (MEXU). Mun. Coacoatzintla , 8 Mar 1985 , F. Vazquez B . 2275 (XAL); 1,400 m , 7 Jan 1977 , G. Castillo-Campos 118 (XAL); 1,550 m , 3 Jun 2005 , L.H. Bojorquez-Galvan & A.M. Zapata-Aquino 1484, 1485 (CIB); 1,435 m , 9 Jan 2015 , L. Martinez-Dominguez et al. 165 - 184 (CIB); 1, 435 m , 18 Mar 2015 , L. Martinez-Dominguez et al. 273-282 (CIB); 1,540 m , 9 Feb 2016 , L. Martinez-Dominguez et al . 759 (CIB). Mun. Jilotepec , 1,300 m , 29 Feb 1980 , A.P. Vovides 470 (XAL), 471 (IBUG, MEXU, XAL); 1,300 m , 14 Apr 1982 , 735 (XAL); 1,385 m , 15 Nov 1978 , E. Estrada et al. 757 (MEXU); 1,316 m , 22 Aug 2014 , F. Nicolalde-Morejon & L. Martinez-Dominguez 2067 - 2086 (CIB); 1,350 m , 7 Dec 1970 , F. Ventura A. 2936 (ENCB); 1,300 m , 22 Jan 1971 , F. Ventura A. 3014 (ENCB); 1,300 m , 18 Nov 1974 , J. Rees 1620 (XAL); 1,363 m , 29 May 2015 , L. Martinez-Dominguez et al. 573 - 583 (CIB); 1,250 m , 23 Aug 1973 , M.G. Zola 657 (XAL), 667 (MEXU, XAL); 1,250 m , 23 Aug 1975 , R. Ortega J. 525 (XAL); Mar 2001 , S. Avendano 5395 (MEXU). Mun. Tepetlan , 1,420 m , 12 Jan 2013 , F. Nicolalde-Morejon et al. 1691 - 1710 (CIB); 1,418 m , 21 Jun 2014 , F. Nicolalde-Morejon & L. Martinez-Dominguez 2001 - 2004 (CIB); 1,418 m , 22 Aug 2014 , F. Nicolalde-Morejon & L. Martinez-Dominguez 2047 - 2066 (CIB); 1,662 m , 10 Apr 2015 , F. Nicolalde-Morejon & L. Martinez-Dominguez 2217 - 2226 (CIB); 1,421 m , 26 Jul 2014 , L. Martinez-Dominguez et al. 160 (CIB); 22 Mar 2015 , L. Martinez-Dominguez & F. Nicolalde-Morejon 283 - 293 (CIB); 1,662 m , 10 Apr 2015 , L. Martinez-Dominguez & F. Nicolalde-Morejon 545-555 (CIB); 2 Jul 2010 , M. Vazquez-Torres et al. 9215 (CIB). Mun. Tlacolulan , 1,540 m , 16 Jun 2017 , F. Nicolalde-Morejon et al. 2516 (CIB); 1,540 m , 16 Jun 2017 , L. Martinez-Dominguez et al. 1041, 1042 (CIB). Mun. Xalapa , 1,270 m , 18 Oct 2016 , F. Nicolalde-Morejon et al. 2466-2468 (CIB); 1,270 m , 18 Oct 2016 , L. Martinez-Dominguez et al. 985, 987 (CIB), 986 (CIB, MEXU).