Dioon sonorense (De Luca, Sabato & Vázquez Torres) Chemnick, Gregory & Salas-Morales (1997:3) Taxonomic revision of the genus Dioon (Zamiaceae) Hernández-Tapia, Jessica E. Jiménez-Ramírez, Jaime Vovides, Andrew P. Phytotaxa 2020 2020-05-13 442 4 267 290 36BDL (De Luca, Sabato & Vazquez Torres) Chemnick, Gregory & Salas-Morales (1997: 3) Chemnick, Gregory & Salas-Morales 3 1997 De Luca, Sabato & Vazquez Torres [136,1345,914,941] Cycadopsida Zamiaceae Dioon Plantae Cycadales 16 283 Tracheophyta species sonorense   MEXICO. Sonora: Álamos, 950 m, without date, Vázquez Torres et al.  V–2308( holotype: XALU!). Basonym:  Dioon tomaselliivar. sonorense De Luca, Sabato & Vázquez Torres (1984: 226).  Dioon edulevar. sonorense(De Luca, Sabato, Vázquez Torres) Mc Vaugh & Pérez de la Rosa (1992: 112). Short plants 0.3–0.6 mtall. Stems 22–25 cmdiameter. Cataphylls triangular-aristate, lanate, 8–16 cmlong, 3 cmwide at the base. Leaves 8–20 per crown, 80–120× 20–25 cm, tomentose, sometimes glabrescent, trichomes light brown. Leaflets 70–90 pairs, falcate, acuminate, reclined to descending, not imbricate, subopposite, margin entire, but sometimes with 1–3 prickles, veins 8–14, the apical leaflets 2–6.8 cmlong, the intermediate 7.6–14.6 cmlong, the basal ones 1–5.5 cmlong, all of them 0.35– 0.35 cmwide, distance between articulations 0.2–0.9 cm, without pinnacanths, tomentose; rachis straight to twisted at the apex, semiterete, tomentose; petioles semiterete to terete, 8– 16.5 cmlong, 0.3–0.9 cmwide, lanate at the base. Male strobili cylindrical, 25–26.5 cmlong, 7–8 cmwide, peduncles short, appearing sessile. Female strobili cylindrical, 21 cmlong, 15 cmwide, peduncles short, appearing sessile; megasporophylls oblong-trulate, flat, 3.6–8.5 cmlong, 2.4–4 cmwide, lanate at the outer surface, the inner surface glabrate, sometimes both surfaces lanate. Seeds globose, 2–2.1 cmlong, 2–2.1 cmwide, sarcotesta yellow to yellow-orange.   Distribution and habitat.—It is distributed in xeric shrublands, oak forests and tropical deciduous forests, including the ecotone of these typesof vegetation in the states of Sinaloaand Sonora. It can be found within 1000– 1800 m, in semiarid climates. The collected individuals in Chihuahuaare cultivated specimens.  Uses and common names.—It is used as an ornamental plant; the stem is used to produce alcohol and as treatment for insect and snake bites as well as articulations. The production of alcohol (Sotol and Bacanora) is an activity that has severely reduced the populations of the species, driving them to the verge of extinction. In the region, the specie is known as palma de la virgen, peineand peyote( Bonta & Osborne 2007).  Taxonomic notes.—It is akin to  D. vovidesiifor presenting reclined to descending leaflets; however, it is distinguished for presenting longer and thinner falcate leaflets, the cataphylls are aristate and the megasporophylls are oblong-trulate. The synonym  Dioon edulevar. gentryiis considered as an invalid name, as there is no publication.  Specimens examined:—  MEXICO.  Chihuahua: Cuahutémoc,  2063 m,  10/September/1994, Bye R. 19387( MEXU).   Sinaloa: Choix,  842 m,  7/May/2004, Walters et al. TW 2004-08 A( MEXU).   Sonora: Álamos,  20/ September/1965, Foster R. s.n.( MEXU);  Álamos,  22/October/1936, Gentry H. S. 2955( MEXU);  Álamos,  1800 m,  19/July/2000, Vovides A. P. et al. 1392( MEXU);  Álamos,  299 m,  30/April/2004, Vovides A. P. et al. 1480( MEXU);  Álamos,  1020 m,  19/July/2000, Vovides A. P. et al. 1389( MEXU);  Álamos,  1122 m,  6/May/2004, Walters T. et al. TW. 2004-06 A( MEXU, SERO, XAL).   Dioon spinulosumDyer ex Eichler (1883: 411). Type:— MEXICO. Yucatán: Progreso, not info, Hoge C. J. s.n.( holotype: K!). Homonym:  Dioon spinulosumDyer (1884:191). Plants (3)5–16(18) m tall. Stems 18–25 cmdiameter. Cataphylls triangular-acuminate, densely lanate, 13–18 cmlong. Leaves 8–40 per crown, 100–250× 20–40 cm, glabrescent, trichomes whitish brown. Leaflets 60–130 pairs, falcate, acuminate, convex, not imbricate, sometimes slightly imbricate, covering less than a third of the width of leaflet, subopposite, the margin spinose with 8–12 prickles, rarely 6–15, veins 12–30, the apical leaflets 3.5–9 cmlong, the intermediate 7.4–19 cmlong. the basal ones 0.1–7 cmlong, all of them (0.8) 1.3–1.8 cmwide, distance between articulations 0.2–2 cm, with pinnacanths, glabrate; rachis straight to semicurved at the apex, terete, glabrate; petioles semiterete, slightly petiolate in adult plants, in young plants elongate petiolate, lanate at the base. Male strobili cylindrical to ovoid, 21–50 cmlong, 1–1.5 cmwide, peduncles short, appearing sessile; microsporophylls cuneate, tomentose, mucronate distally, 1.4–2.5 cmlong, sori with 3–6 sporangia. Female strobili cylindrical to ovoid, 35–50 cmlong, 20–27 cm, elongated peduncle; megasporophylls deltoid, flat, 6.5–8 cmlong, 3.2–5 cmwide, lanate on the outer surface, the inner surface glabrate. Seed ovoid to ellipsoid, 3.4–4.8 cmlong, 2.4–3.1 cmwide, sarcotesta yellow.  Distribution and habitat.—Along with  D. rzedowskii, it’s distributed only in tropical rainforests, in very humid regions in the states of Oaxacaand Veracruz, within the 50– 600 m.  Uses and common names.—It is used as an ornamental plant. Seed husks are used to make bullroarers ( zumbadores). In the region, it is known as coyolito de cerro, palma de chicle, palma de chicalite, palma de Dolores, chicalitoand coyolillo(Bonta & Osborn 2007).  Taxonomic notes.—It is akin to  D. rzedowskiibut it is distinguished for presenting (6)8–12(15) prickles at the margin of the leaflets and the seeds are usually ellipsoid. Within the genus, it is the largest species, reaching 18 mtall in the oldest specimens. The name  Dioon spinulosumvar. spinulosumis in fact an invalid name because it lacks publication and typespecimen.  Specimens examined:—  MEXICO.  CDMX: Jardín Botánico, Ciudad Universitaria,  4/July/2006,  Abrego E. & González H. 1( UAMIZ).  Oaxaca: Acatlán de Pérez Figueroa,  220 m,  8/October/2001, Guízar E. & Echeverría J. C. 5724( MEXU, UAMIZ);  Acatlán de Pérez Figueroa,  110 m,  25/January/2008,  Salas-Morales6348( SERO);  San José Chiltepec,  150 m,  8/January/1988,  López A. R. et al. 456( UAMIZ);  San Juan Bautista Tuxtepec, July/1963,  Alcocer J. M. & Morales C. s.n.( ENCB, MEXU);  San Juan Bautista Tuxtepec, February/1962, s.n.( FCME);  San Juan Bautista Tuxtepec,  300 m,  10/April/1963,  Madrigal X.1458( ENCB, MEXU);  San Juan Bautista Tuxtepec,  200 m,  6/February/1967,  Martínez M. A. 11( ENCB);  San Juan Bautista Tuxtepec,  18/September/1947,  Miranda F. 4227( MEXU);  San Juan Bautista Tuxtepec,  25/May/1961,  Sousa M. s.n.( FCME);  San Juan Bautista Tuxtepec,  20/ May/1961,  Sousa M. s.n.( FCME);  San Juan Bautista Tuxtepec,  100 m,  7/July/1980,  Vovides A. P. 547( MEXU);  San Juan Bautista Tuxtepec,  100 m,  19/January/1982,  Vovides A. P. & Pattison G. 718( ENCB);  San Juan Bautista Tuxtepec,  100 m,  7/July/1980,  Vovides A. P. & Pattison G. 547( ENCB);  San Juan Bautista Valle Nacional,  250 m,  25/April/1993,  Ibarra G. 3881( MEXU);  San Soyaltepec,  60 m,  21/May/1986,  Cortes L. 379( MEXU);  San Soyaltepec,  150 m,  8/ December/1985,  Cortes L. 118( MEXU);  San Soyaltepec,  154 m,  12/November/2004,  Juárez G. 858( MEXU);  San Soyaltepec,  116 m,  6/January/2014,  Salas-Morales7526( SERO);  San Soyaltepec,  20/October/1962,  Sousa M. 1783( MEXU);  San Soyaltepec,  19/February/1961,  Sousa M. 268( MEXU);  Santa María Jacatepec,  165 m,  23/April/1993,  Carrillo C. 176( MEXU);  Santa María Jacatepec, 550-  270 m,  19/January/1988,  Torres R. 11066( MEXU);  Santa María Jacatepec,  140 m,  5/September/1984,  Torres R. 6107( MEXU);  Santiago Jocotepec,  90 m, 29/ Nocember/2003,  Castillo-Campos G. et al. 20791( MEXU).  Veracruz: Tezonapa,  600 m,  9/December/1974,  Rees J. 1648( MEXU).   Dioon stevensoniiNicolalde-Morejón. & Vovides (2009:74). Type:— MEXICO. Guerrero: Coyuca de Catalán, 1181 m, 13/March/2007, Nicolalde-Morejón F. et al. 1551( holotype: XAL!, isotypes: MEXU!). ( Fig. 3). Plants 1.2 mtall. Stems 26 cmdiameter. Cataphylls triangular-acuminate, lanate, 6–7 cmlong, 1.5–3 cmwide. Leaves 2–25 per crown, 69–111× 21–23 cm, tomentose on the underside, trichomes golden brown. Leaflets 50–100 pairs, linear-lanceolate, sometimes subfalcate, acuminate, flat-convex, not imbricate, but sometimes slightly imbricate, covering less than a third of the distal region of the leaf, opposite to subopposite, margin entire, sometimes with 1–4 prickles at the leaflet apex, veins 11–20, the apical leaflets 1.1–4.5 cmlong, the intermediate 4.3–14.5 cmlong, the basal ones 1.3–5.8 cmlong, all of them 0.5–1 cmwide, distance between articulations 0.2–0.5 cm, without pinnacanths, tomentose; rachis straight to twisted at the apex, semiterete, tomentose at the insertion of leaflet; petioles semiterete, 8– 19.5 cmlong, 0.4–1 cmwide, lanate at the base. Male strobili cylindrical, 16–25 cmlong, 7.2–75 cmwide, peduncles short, appearing sessile; microsporophylls cuneate, tomentose, mucronate distally, 1.6–2.2 cmlong, sori with 4–5 sporangia. Female strobili ovoid, 30–35 cmlong, 10–15 cmwide, peduncles short, appearing sessile; megasporophylls deltoid, flat to curved at the apex, 7.5–9.5 cmlong, 3.5–4.5 cmwide, lanate on the outer surface, the apex occasionally glabrate, the inner surface glabrate. Seed globose to ovoid, 2.2–3.5 cmlong, 2–3 cmwide, sarcotesta yellow.  Distribution and habitat.—It is found in oak forest, tropical deciduous forest and the ecotone between these two typesof vegetation. It is endemic to the states of Guerreroand border Michoacánwith Guerrero. It is listed as a Critically Endangered species (CR) in the IUCN Red List due to the poaching of plants for sale as ornamentals as well as the loss of habitat. It thrives in temperate to warm humid regions, within the 400–1550 m.  Uses and common names.—It is only used as an ornamental plant. In these regions, it is known as palmaand palmita( Bonta et al.2019).  Taxonomic notes.—The main difference between  D. stevensoniiand  D. tomaselliiis that the former species presents megasporophylls with flat apices, but the rest of the sporophyll is curved, the leaflets tend to be linear-lanceolate and very rarely subfalcate.  D. tomaselliipresents a completely flat megasporophyll and falcate leaflets.  Specimens examined:—  MEXICO.  Guerrero: Arcelia,  1550 m,  6/December/1983, Sabato et al. 2335( MEXU);  Arcelia,  400 m, without date,  Vázquez M.  V-2305, V-2325( XALU);  Arcelia,  1397 m,  18/May/2004, Walters T. et al. TW 2004-18 B( SERO);  Coyuca de Catalán,  1215 m,  3/May/2001, Vovides A. P. et al. 1414( MEXU);  Zirándaro,  1210 m,  6/November/1998, Calónico J. 12162( FCME, MEXU);  Zirándaro,  1120 m,  22/June/1999, Calónico J. 15242( FCME, MEXU);  Zirándaro,  1120 m,  22/July/1999, Calónico J. 15421( FCME, MEXU);  Zirándaro,  1200 m,  9/March/1988, Contreras J. L. 2359( FCME);  Zirándaro,  1100 m,  15/June/1988, Contreras J. L. 2399( FCME);  Zirándaro,  1100 m,  16/June/1988, Contreras J. L. 2397, 2400( FCME);  Zirándaro,  1150 m,  14/July/1982, Martínez 1993( MEXU);  Zirándaro,  1397 m,  18/May/2004, Walters T. et al. TW 2004-18 A( MEXU);  Zirándaro,  940 m,  2/May/2001, Vovides A. P. et al. 1398, 1399, 1400, 1401( XAL);  Zirándaro,  1100 m,  2/May/2001, Vovides A. P. et al. 1404, 1405, 1406, 1407( XAL).   Michoacán: Arteaga,  840 m,  16/May/2004, Walters et al. TW 2004-15 A( MEXU). 1994-09-10 R, MEXU Mexico 2063 Cuahutemoc 16 283 1 Chihuahua [258,1183,1886,1913] 2004-05-07 A, MEXU Mexico 842 Choix 16 283 1 Sinaloa 1965-09-20 R, MEXU Mexico Alamos 16 283 1 Sonora [614,1243,1922,1951] 1936-10-22 H, S, MEXU Mexico Alamos 16 283 1 Sonora 2000-07-19 A, P, MEXU Mexico 1800 Alamos 16 283 1 Sonora [697,1447,1958,1987] 2004-04-30 A, P, MEXU Mexico 299 Alamos 16 283 1 Sonora [136,871,1994,2023] 2000-07-19 A, P, MEXU Mexico 1020 Alamos 16 283 1 Sonora 2004-05-06 T, A, MEXU, SERO, XAL Mexico 1122 Alamos 16 283 1 Sonora 2001-10-08 2006-07-04 2001-10-08 CDMX, E, H, UAMIZ, J, C, MEXU Mexico Jardin Botanico 220 Abrego Ciudad Universitaria 17 284 1 Oaxaca [459,1396,1130,1157] 2008-01-25 SERO Salas-Morales Mexico 110 Acatlan de Perez Figueroa 17 284 1 1988-01-08 A, R, UAMIZ San Jose Chiltepec & Lopez Mexico 150 17 284 1 J, M, C, ENCB, MEXU San Juan Bautista Tuxtepec & July & Alcocer & Morales Mexico 17 284 1 [732,1395,1202,1229] FCME San Juan Bautista Tuxtepec & February Mexico 17 284 1 1963-04-10 ENCB, MEXU San Juan Bautista Tuxtepec & Madrigal X. Mexico 300 17 284 1 1967-02-06 M, A, ENCB San Juan Bautista Tuxtepec & Martinez Mexico 200 17 284 1 1947-09-18 F, MEXU San Juan Bautista Tuxtepec Mexico 17 284 1 [318,1074,1310,1337] 1961-05-25 M, FCME San Juan Bautista Tuxtepec Mexico 17 284 1 1961-05-20 M, FCME San Juan Bautista Tuxtepec Mexico 17 284 1 [534,1398,1346,1373] 1980-07-07 A, P, MEXU San Juan Bautista Tuxtepec & Vovides Mexico 100 17 284 1 1982-01-19 A, P, G, ENCB San Juan Bautista Tuxtepec & Vovides & Pattison Mexico 100 17 284 1 1980-07-07 A, P, G, ENCB San Juan Bautista Tuxtepec & Vovides & Pattison Mexico 100 17 284 1 1993-04-25 G, MEXU San Juan Bautista Valle Nacional Mexico 250 17 284 1 [437,1138,1454,1481] 1986-05-21 L, MEXU San Soyaltepec & Cortes Mexico 60 17 284 1 1985-12-08 L, MEXU San Soyaltepec & Cortes Mexico 150 17 284 1 [612,1396,1490,1517] 2004-11-12 G, MEXU San Soyaltepec & Juarez Mexico 154 17 284 1 2014-01-06 SERO Salas-Morales Mexico 116 San Soyaltepec 17 284 1 1962-10-20 M, MEXU San Soyaltepec Mexico 17 284 1 [253,922,1562,1589] 1961-02-19 M, MEXU San Soyaltepec Mexico 17 284 1 1993-04-23 C, MEXU Santa Maria Jacatepec & Carrillo Mexico 165 17 284 1 [448,1374,1598,1625] 1988-01-19 R, MEXU Santa Maria Jacatepec & Torres Mexico 270 17 284 1 1984-09-05 R, MEXU Santa Maria Jacatepec & Torres Mexico 140 17 284 1 1974-12-09 G, MEXU, J Santiago Jocotepec & Nocember & Castillo-Campos & Rees Mexico 90 Tezonapa 17 284 1 Veracruz de Ignacio de la Llave [474,1447,662,689] 1983-12-06 MEXU Mexico 1550 Arcelia 18 285 1 Guerrero [136,876,698,725] V- 2305, V- 2325 M, XALU Mexico 400 Vazquez Arcelia 18 285 1 Guerrero 2004-05-18 T, B, SERO Mexico 1397 Arcelia 18 285 1 Guerrero [366,1224,734,761] 2001-05-03 A, P, MEXU Mexico 1215 Coyuca de Catalan 18 285 1 Guerrero 1998-11-06 J, FCME, MEXU Mexico 1210 Zirandaro 18 285 1 Guerrero 1999-06-22 J, FCME, MEXU Mexico 1120 Zirandaro 18 285 1 Guerrero [244,1046,806,833] 1999-07-22 J, FCME, MEXU Mexico 1120 Zirandaro 18 285 1 Guerrero 1988-03-09 J, L, FCME Mexico 1200 Zirandaro 18 285 1 Guerrero [502,1254,842,869] 1988-06-15 J, L, FCME Mexico 1100 Zirandaro 18 285 1 Guerrero 1988-06-16 J, L, FCME Mexico 1100 Zirandaro 18 285 1 Guerrero [774,1447,878,905] 1982-07-14 MEXU Mexico 1150 Zirandaro 18 285 1 Guerrero [136,970,914,941] 2004-05-18 T, A, MEXU Mexico 1397 Zirandaro 18 285 1 Guerrero 2001-05-02 A, P, XAL Mexico 940 Zirandaro 18 285 1 Guerrero 2001-05-02 A, P, XAL Mexico 1100 Zirandaro 18 285 1 Guerrero [226,1156,985,1013] 2004-05-16 A, MEXU Mexico 840 Arteaga 18 285 1 Michoacan de Ocampo