Tree and tree-like species of Mexico: Euphorbiaceae, Peraceae, Phyllanthaceae, Picrodendraceae, Putranjivaceae, and Urticaceae

Especies arbóreas y arborescentes de México: Euphorbiaceae, Peraceae, Phyllanthaceae, Picrodendraceae, Putranjivaceae y Urticaceae

In the majority of terrestrial ecosystems, trees are the most conspicuous components and dominate the landscape in terms of coverage and biomass. However, with regard to overall diversity, they are often surpassed by shrubby and/or herbaceous species. For Mexico, the total number of vascular plant species is estimated to be over 23,000 (Villaseñor, 2016), and approximately 2,500 (11%) of these are considered to be trees (Rzedowski, 1991). However, there is no single definition in the literature of what constitutes a tree. In Ricker and Hernández (2010), and slightly expanded in Ricker et al. (2013), trees or tree-like plants were defined broadly as perennial, self-supporting plants with a total height of at least 5 m, without ascending leaves or inflorescences, and with 1 or several erect stems with a diameter of at least 10 cm, measured at 1.3 m above the ground level, or measured above buttresses if these are present. A tree or tree-like species contains individuals with tree characteristics at least somewhere in its geographic range, but not necessarily everywhere. Our definition avoids the often arbitrary distinction of “trees” with a dominant trunk, from large “shrubs” with multiple stems. The term “self-supporting” excludes lianas, and the minimum diameter of 10 cm assures some type of a trunk that is typically associated with the term tree. Overall, however, the definition is anthropocentric, focused on plants that are individually impressive elements of a landscape from a human viewpoint. There are also plant species that could be considered trees, but do not comply with the above definition, and thus are not included in our compilation: tree-like (woody) species that are smaller than 5 m, or present a diameter of less than 10 cm, could be distinguished as “shrubs” or “dwarf trees.” The same is true for plants that are higher than 5 m, but do not present a diameter of 10 cm, such as some bamboo species (Poaceae).

After discussing the tree definition and emphasizing the need for an updated taxonomic list of Mexico’s tree species, Ricker and Hernández (2010) presented 170 species of gymnosperms, monocotyledons, and tree ferns. In Ricker et al. (2013), the work was continued with 619 species in the species-rich plant families Asteraceae, Leguminosae, and Rubiaceae. Subsequently, Ricker et al. (2016) presented 271 tree species in the families Apocynaceae, Cactaceae, Ebenaceae, Fagaceae, and Sapotaceae. In the current contribution, we report 178 tree species in 6 plant families: Euphorbiaceae, Peraceae, Phyllanthaceae, Picrodendraceae, Putranjivaceae, and Urticaceae.

Throughout the 20^th century and during the first years of the 21^st century, Peraceae, Phyllanthaceae, Picodendraceae, and Putranjivaceae were included within Euphorbiaceae (e.g., Radcliffe-Smith, 2001; Webster, 1994). However, these taxa have subsequently been segregated as independent families (Angiosperm Phylogeny Group, 2016; Tokuoka, 2007; Wurdack & Davis, 2009; Wurdack et al., 2004, 2005). With regard to Urticaceae, it is here circumscribed to include Cecropiaceae, following Sytsma et al. (2002) and the Angiosperm Phylogeny Group (2016). Whereas Euphorbiaceae and its segregates are all closely related families within the Malpighiales, the distantly related Urticaceae belongs to the Rosales. Taxonomic descriptions of the families Euphorbiaceae, Phyllanthaceae, Picrodendraceae, Putranjivaceae, and Urticaceae can be found in Heywood et al. (2007). Esser (2009) provides a description of Peraceae.

Generally speaking, our understanding of the arborescent Mexican species of Euphorbiaceae is incomplete. The only truly complete Floras for Mexico are those of the Sonoran Desert (Wiggins, 1964), Baja California (Wiggins, 1980), and the Valley of Mexico (Calderón-de Rzedowski & Rzedowski, 2001), and Euphorbiaceae trees are absent from all of those regions. The family has yet to be revised for any of the major on-going floristic projects, such as the “Flora del Bajío y de Regiones Adyacentes” (http://inecolbajio.inecol.mx/floradelbajio/), “Flora de Guerrero” (http://biologia.fciencias.unam.mx/plantasvasculares/publicaciones.html), “Flora Mesoamericana” (http://legacy.tropicos.org/Project/FM), “Flora de Veracruz” (http://www1.inecol.edu.mx/floraver/), and “Flora de Jalisco y Áreas Colindantes” (https://www.yumpu.com/user/floradejalisco.cucba.udg.mx). It is noteworthy that, although it was not completed for the “Flora Novo-Galiciana” (discontinued), a few useful preliminary taxonomic treatments of portions of the family were published (McVaugh, 1961, 1993, 1995; Webster, 2001a), and these include some of the tree species of the appendix. The only major on-going floristic project that includes Euphorbiaceae is the “Flora del Valle de Tehuacán-Cuicatlán,” but only the description of 4 genera of the subfamily Crotonoideae has been published (Martínez-Gordillo et al., 2014), and of the 30 species included, only 6 are trees. There are taxonomic accounts of the family for Aguascalientes (de la Cerda-Lemus, 2011) and Sonora (Steinmann & Felger, 1997). For the latter state, there is also a revision of the trees (Felger et al., 2001). However, in both of these states, there are few Euphorbiaceae trees. Despite the lack of taxonomic treatments of the Euphorbiaceae in published floras, there are various important revisions or synopses that include many tree species, such as those covering Bernardia (Cervantes-Maldonado, 2002), Cnidoscolus (Breckon, 1975), Croton (Martínez-Gordillo, 1995, 1996), portions of Euphorbia (Dressler, 1957; Ramírez-Roa, 1997), Garcia (Lundell, 1945), Jatropha (Dehgan, 2012), and Mabea (Martínez-Gordillo et al., 2000).

For Phyllanthaceae, the family has been completed for the “Flora del Bajío y de Regiones Adyacentes” (Steinmann, 2007) and “Flora del Valle Tehuacán-Cuicatlán” (Martínez-Gordillo & Cervantes-Maldonado, 2009), but in the latter area no tree species occur, and in the former there are only 2 tree species. There are revisions of the genera Astrocasia (Webster, 1992) and Margaritaria (Webster, 1979).

The family Urticaceae is better studied, and was revised in the “Flora Mesoamericana” series (pages 116-174 in Davidse et al., 2015), which includes Central America in addition to the Mexican states of Tabasco, Chiapas, Campeche, Quintana Roo, and Yucatán. It was also completed for the “Flora del Bajío y de Regiones Adyacentes” (Steinmann, 2005) and the “Flora del Valle de Tehuacán-Cuicatlán” (Steinmann, 2009). Additional information is found in revisions of the genera Boehmeria (Wilmot-Dear & Friis, 1996), Cecropia (Berg, 2015; Berg & Franco-Rosselli, 2005), Coussapoa (Berg et al., 1990), Myriocarpa (Monro, 2009), Pourouma (Berg et al., 1990), and Urera (Monro & Rodríguez-González, 2009).

The 3 smaller families Peraceae, Picrodendraceae, and Putranjivaceae similarly lack substantial taxonomic treatments, although Putranjivaceae was completed for the “Flora del Bajío y de Regiones Adyacentes” (Steinmann, 2001). Furthermore, there is a revision of a portion of its genus Drypetes (Levin, 2013) that includes one of the Mexican trees.

Materials and methods

The list of species is presented in an appendix that provides the scientific names of the tree species (as defined above), with original publication, references of recent taxonomic revisions, in some cases synonyms, existence of subspecies or varieties, maximum height in Mexico, and the indication if the species is endemic to Mexico. Only species native to Mexico were included in the appendix, and naturalized species such as Ricinus communis L. are not included.

In addition to an exhaustive review of the pertinent literature, including all references mentioned in the introduction, extensive herbarium work was conducted. For all species, the specimens in the National Herbarium of Mexico (MEXU, Ciudad de México) were examined for growth form, height, and trunk diameter. The following herbaria were also consulted: ARIZ (Tucson, Arizona), QMEX (Querétaro, Querétaro), IBUG (Guadalajara, Jalisco), and RSA/POM (Claremont, California). In some cases, field observations were made.

Endemism refers to the species distribution being restricted to Mexico, as far as currently known, and the endemism status was also verified by herbarium records, if it was not clear from the literature. The heights reported in the appendix refer to the maximum heights reached by the species in some region of Mexico. Exceptional height values for Mexico are given in parenthesis, and when deemed relevant, heights in other countries are also reported in parenthesis. Where reasonable doubts remained about the trunk diameter reaching at least 10 cm or the height 5 m, the species was not included.

Recent literature with taxonomic descriptions for the recognized species names are cited in the appendix, whenever available. The authors of species names and original publications were verified in Tropicos (www.tropicos.org). Synonyms are mentioned only in cases when they reflect diverging opinions among different taxonomic specialists. For synonyms, species’ author names are not provided here, but can be found in Tropicos.

Results

In total, 178 species are reported for the 6 families treated in this contribution. The most relevant results are summarized in Table 1. Most species (75%) belong to the Euphorbiaceae, followed by the Urticaceae (15%). Croton and Jatropha (both Euphorbiaceae) are the genera with most species treated here (25 and 20, respectively).

Mexico has a high level of endemism, and Villaseñor (2016) reports that approximately 50% of the species could be endemic to the country. This is comparable to the 52% estimate provided by Rzedowski (1991). For the families in our contribution, the Euphorbiaceae follows this trend closely, having 53% of its trees endemic to Mexico. However, for the Urticaceae, only 7% of the tree species are endemic. For the 4 smaller families, 12% (2 of 17) are endemic. Collectively, the level of endemism is 42%, or slightly less than the national average. A single genus is endemic: Enriquebeltrania.

The tallest Mexican trees previously reported in this project belong to Leguminosae, Pinaceae and Rubiaceae, which can reach heights of more than 70 m. Species of Apocynaceae, Cupressaceae, Fagaceae and Sapotaceae exceed 60 m (Ricker & Hernández, 2010; Ricker et al., 2013, 2016). None of the families treated in this contribution have trees reaching 50 m in Mexico (as far as known) and only 2 exceed 40 m: Tetrorchidium rotundatum and Hieronyma alchorneoides. By far, the diversity is found in small trees, and 103 species are 10 m tall or less.

Discussion

The vast majority of the species covered in this contribution belong to Euphorbiaceae, the fifth most diverse family of vascular plants in Mexico (Villaseñor, 2016). It includes over 700 native Mexican species (Steinmann, 2002; Villaseñor, 2016), but according to our compilation only 134 species (about 19%) are trees. With regard to the small families Peraceae and Putranjivaceae, all 4 of the Mexican species are trees, whereas only 1 of the 4 Mexican species of Picrodendraceae shares this habit. Of the estimated 49 native Mexican Phyllanthaceae (Villaseñor, 2016), we here report 12 species of trees (24%). Finally, concerning Urticaceae, an estimated 91 native species occur in the country (Villaseñor, 2016), of which 27 are trees (30%).

Among the Mexican tree species of Euphorbiaceae are a number of economically important taxa. By far, the most significant of these is the Christmas Poinsettia, Euphorbia pulcherrima, one of the world’s most lucrative ornamental plants. Although the cultivars are grown almost exclusively as herbaceous, the species occurs natively as a tree in western and central Mexico (Trejo et al., 2012). Cnidoscolus aconitifolius, the “chaya,” is cultivated locally, and its leaves are consumed for their highly nutritious composition (Ross-Ibarra & Molina-Cruz, 2002). The latex of C. tepiquensis is collected and employed in Jalisco and Nayarit to make souvenir figurines (Cházaro-Basáñez & Guerrero-Nuño, 1995). Considerable quantities of Croton lindquistii and other species of Croton section Eluteria, such as C. pseudoniveus and C. reflexifolius, are harvested in northwestern Mexico for their straight, durable trunks, which are used in construction and as posts for the cultivation of crops (Steinmann, 2014). Jatropha curcas is currently being investigated as a source of biodiesel and also has medicinal uses (Abdelgadir & Van Staden, 2013). Various other species have regional importance in traditional medicine, e.g., Croton arboreus, C. draco, and C. schiedeanus (Barrera et al., 2016). The large leaves of Omphalea oleifera are used to wrap cheeses, and its seeds are consumed like a nut and also used for the preparation of soaps and cooking oils (Gillespie, 1988).

In the Urticaceae, the pioneer tropical forest tree Cecropia obtusifolia plays an important ecological role in early successional communities and has various medicinal uses (Pérez-Guerrero et al., 2001). Myriocarpa longipes is also used medicinally and its large leaves are used to wrap meat and tamales (Steinmann, 2005).

Table 1

Summary of the data in the Appendix ¹

Family	Tree species	Endemic tree species	Tallest species	Tree genera	Genera with most tree species
Euphorbiaceae	134	71 (53%)	Tetrorchidium rotundatum (45 m)	23	Croton (25 species), Jatropha (20)
Peraceae	1	0	Pera barbellata (20 m)	1	Pera (1)
Phyllanthaceae	12	0	Hieronyma alchorneoides (40 m, 60 m in Costa Rica)	5	Phyllanthus (6)
Picrodendraceae	1	1	Piranhea mexicana (25 m)	1	Piranhea (1)
Putranjivaceae	3	1	Drypetes gentryi (30 m)	1	Drypetes (3)
Urticaceae	27	2 (7%)	Cecropia obtusifolia (35 m)	9	Myriocarpa (7), Urera (7)
Total of all families	178	75 (42%)		40

¹ Enriquebeltrania (Euphorbiaceae) is the only endemic genus.

All of the families treated here are either entirely tropical (Peraceae and Putranjivaceae) or primarily tropical (Euphorbiaceae, Picrodendraceae, Phyllanthaceae, and Urticaceae). With regard to floristic affinities, only 3 of the 178 species also occur in the continental United States. Two of them are restricted to tropical southern Florida: Gymnanthes lucida (Euphorbiaceae) and Drypetes lateriflora (Putranjivaceae); Jatropha cinerea barely enters in the county in southwestern Arizona. Whereas 14 species extend into the Antilles, the greatest affinities are with the tropical forests of Central and/or South America, where 101 species also occur. No species is distributed natively in the paleotropics.

There is no comprehensive evaluation of the conservation status of any of the families treated in this contribution. In fact, less than a third of the tree species have been evaluated, be it by the criteria of the International Union for Conservation of Nature (IUCN, 2012) or the alternative “Método de evaluación del riesgo de extinción de las especies silvestres en México” (Semarnat, 2002). Only 6 of the arborescent species of Euphorbiaceae have been assigned a risk category in the “Norma Oficial Mexicana NOM-059” (Semarnat, 2019). These include Bernardia mollis (threatened), Cnidoscolus autlanensis (subject to special protection), Croton guatemalensis (subject to special protection), Euphorbia coalcomanensis (threatened), Sapium macrocarpum (threatened), and Tetrorchidium rotundatum (threatened). However, this list certainly is not an accurate representation of the endangered taxa, and many more species are at risk than indicated by the “Norma Oficial Mexicana NOM-059.” For example, a recent assessment of some species belonging to Jatropha subgenus Curcas determined that of the 12 Mexican tree species included, 7 are either threatened or near-threatened, with 2 of them being endangered: Jatropha pereziae and J. stephani (Christensen et al., 2019). Additionally, a study of 37 Mexican cloud forest trees by González-Espinosa et al. (2012) determined that in Euphorbiaceae, Phyllanthaceae, and Urticaceae, 15 (41%) of the evaluated species are worthy of some level of conservation concern (1 critically endangered, 4 endangered, 7 vulnerable, and 3 near threatened). The fact that most species lack even a preliminary evaluation, let alone any management strategies, support the urgency to evaluate the conservation status of more trees in these families.

Acknowledgments

We thank the following herbaria for permission to examine their collections: ARIZ (Tucson, Arizona), IBUG (Guadalajara, Jalisco), RSA/POM (Claremont, California), in addition to the herbaria of the institutions where we work, QMEX (Querétaro, Querétaro) and MEXU (Ciudad de México). Lynn J. Gillespie kindly provided useful information about the genus Omphalea.

Appendix. List of tree species with original publication, references of taxonomic revisions, in some cases synonyms, existence of subspecies or varieties, maximum height in Mexico, and indication if endemic to Mexico.

Euphorbiaceae

Acalypha diversifolia N. J. von Jacquin, Plantarum Rariorum Horti Caesarei Schoenbrunnensis 2: 63. 1797. (González, 2010: 301; Parker, 2008: 259-260). 8(-15) m.

Acalypha lancetillae P. C. Standley, Publications of the Field Museum of Natural History, Botanical Series 4(8): 312. 1929. (Parker, 2008: 260). 6 m (often smaller and shrubby).

Acalypha macrostachya N. J. von Jacquin, Plantarum rariorum horti caesarei schoenbrunnensis 2: 63. 1797. (González, 2010: 302; Parker, 2008: 261). 8 m (but generally smaller and shrubby).

Acalypha mortoniana C. L. Lundell, Bulletin of the Torrey Botanical Club 64(8): 552. 1937. (Parker, 2008: 261; González, 2010: 302). 9 m (often smaller and shrubby).

Acalypha skutchii I. M. Johnston, Journal of the Arnold Arboretum 19(2): 120. 1938. (Parker, 2008: 261). 6(-12) m (often shrubby).

Acalypha villosa N. J. von Jacquin. Enumeratio systematica plantarum, quas in insulis caribaeis 32. 1760. (Múnoz-Rodríguez et al., 2014: 213-214; Parker, 2008: 262; González, 2010: 305). 7 m (often smaller and shrubby).

Acidocroton madrigalensis A. Hanan et V. W. Steinmann, Acta Botanica Mexicana 104: 94. 2013. 5 m. Endemic.

Acidocroton spinosus (P. C. Standley) G. L. Webster, Annals of the Missouri Botanical Garden 81(1): 107. 1994. 18 m (in some portions of its distribution smaller and shrubby).

Adelia barbinervis D. F. von Schlechtendal et L. K. von Chamisso, Linnaea 6: 362. 1831. (De-Nova et al., 2007: 587-588; Parker, 2008: 263; Rzedowski, 2015: 52). 9 m (often smaller and shrub-like).

Adelia brandegeei V.W. Steinmann, Acta Botanica Mexicana 61: 60. 2002. (De-Nova et al., 2007: 588-589; Felger et al., 2001: 146-147; Steinmann & Felger, 1997: 17). This name replaces Adelia virgata T.S. Brandegee (1894) non A. virgata J.L. Poiret (1810). 6 m (but mostly smaller and shrub-like). Endemic.

Adelia oaxacana (J. Müller) W. B. Hemsley, Biologia centrali-americana […] Botany 3(15): 129. 1883. (De-Nova et al., 2007: 591). 8 m (often smaller and shrub-like). Endemic.

Alchornea chiapasana F. Miranda, Ceiba 4(2): 131. 1954. (Secco, 2004: 129-131). 17(-30) m. Endemic.

Alchornea latifolia O. Swartz, Nova Genera et Species Plantarum seu Prodromus 98. 1788. (González, 2010: 311; Parker, 2008: 264; Pennington & Sarukhán, 2005: 308-309; Rzedowski, 2015: 55; Secco, 2004: 103-108). 30 m.

Bernardia albida C. L. Lundell, Wrightia 5(7): 245. 1976. (Cervantes-Maldonado, 2002: 58-64). 5 m (often smaller and shrubby). Endemic.

Bernardia chinantlensis A. Cervantes et H. Flores, Botanical Journal of the Linnean Society 149: 244. 2005. 10 m (often smaller). Endemic.

Bernardia dodecandra (M. Sessé ex A. J. Cavanilles) R. McVaugh, Botanical Results of the Sessé & Mociño Expedition (1787-1803) 222. 2000. (Cervantes-Maldonado, 2002: 75-83; Parker, 2008: 266). Bernardia interrupta is considered a synonym. 10 m (often smaller).

Bernardia fonsecae A. Cervantes et J. Jiménez, Novon 12(1): 38. 2002. (Cervantes-Maldonado, 2002: 87-91). 18 m. Endemic.

Bernardia gentryana L. Croizat, Journal of the Arnold Arboretum 24: 165. 1943. (Cervantes-Maldonado, 2002: 91-95; Steinmann & Felger, 1997: 18). 6 m (often smaller and shrubby). Endemic.

Bernardia heteropilosa McVaugh, Brittonia 13: 155. 1961. (Cervantes-Maldonado, 2002: 95-97). 5 m. Endemic.

Bernardia macrocarpa A. Cervantes et H. Flores, Botanical Journal of the Linnean Society 149: 247. 2005. (Cervantes-Maldonado, 2002: 109-111). 15 m. Endemic.

Bernardia mexicana (W. J. Hooker et G. Arnott) J. Müller, Linnaea 34: 171. (Cervantes-Maldonado, 2002: 116-122). 1865. 5(-10) m.

Bernardia mollis C. L. Lundell, Contributions from the University of Michigan Herbarium 4: 12. 1940. (Cervantes-Maldonado, 2002: 125-129; Parker, 2008: 266). 15 m.

Bernardia oblanceolata C. L. Lundell, Contributions from the University of Michigan Herbarium 4: 13. 1940. (Cervantes-Maldonado, 2002: 136-139; Parker, 2008: 266). 10(-20) m.

Bernardia santanae McVaugh, Contributions from the University of Michigan Herbarium 20: 194. 1995. (Cervantes-Maldonado, 2002: 153-156). 7 m. Endemic.

Bernardia wilburii McVaugh, Brittonia 13: 157. 1961. (Cervantes-Maldonado, 2002: 172-173, 175). 5 m. Endemic.

Bernardia yucatanensis C. L. Lundell, Contributions from the University of Michigan Herbarium 4: 14. 1940. (Cervantes-Maldonado, 2002: 173-177; Parker, 2008: 266). 5(-12) m.

Cleidion castaneifolium J. Müller, Linnaea 34: 184. 1865. (González, 2010: 319; Parker, 2008: 267). 15 m.

Cnidoscolus aconitifolius (P. Miller) I. M. Johnston, Contributions from the Gray Herbarium of Harvard University 68: 86. 1923. (Breckon, 1975: 323-362; González, 2010: 320; Parker, 2008: 267-268; Fernández-Casas, 2014: 6-8, 12; Maya-Lastra & Steinmann, 2018: 3-4). Cnidoscolus chayamansa is considered a synonym. 8 m.

Cnidoscolus autlanensis G. Breckon, Contributions from the University of Michigan Herbarium 20: 201. 1995. (Breckon, 1975: 276-285; Maya-Lastra & Steinmann, 2018: 7). 6 m. Endemic.

Cnidoscolus elasticus C. L. Lundell, Field & Laboratory 12(2): 33. 1944. (Breckon, 1975: 263-272; Maya-Lastra & Steinmann, 2018: 10). 10 m. Endemic.

Cnidoscolus megacanthus G. Breckon ex F. J. Fernández, Fontqueria 55(63): 492. 2008. (Breckon, 1975: 375- 387; González, 2010: 321; Maya-Lastra & Steinmann, 2018: 13). 6(-8) m.

Cnidoscolus monicanus L. A. Lomelí, E. Sahagun et V. W. Steinmann, Novon 19(1): 69. 2009. (Maya-Lastra & Steinmann, 2018: 14). 20 m. Endemic.

Cnidoscolus multilobus (F. Pax) I. M. Johnston, Contributions from the Gray Herbarium of Harvard University 68: 86. 1923. (Breckon, 1975: 230-262; Fernández-Casas, 2014: 18-21; Maya-Lastra & Steinmann, 2018: 14-15; Parker, 2008: 268; Pennington & Sarukhán, 2005: 310-311). Four subspecies, all in Mexico (Breckon, 1975: 230-262; Maya-Lastra & Steinmann, 2018: 14-15). 12 m.

Cnidoscolus sinaloensis G. Breckon ex F. J. Fernández, Fontqueria 55: 509. 2008. (Breckon, 1975: 312-322; Maya-Lastra & Steinmann, 2018: 18). 8 m. Endemic.

Cnidoscolus souzae R. McVaugh, Bulletin of the Torrey Botanical Club 71(5): 468. 1944. (Breckon, 1975: 363- 374; Maya-Lastra & Steinmann, 2018: 18). 7 m.

Cnidoscolus spinosus C.L. Lundell, Bulletin of the Torrey Botanical Club 72(3): 329. 1945. (Breckon, 1975: 286-298; Maya-Lastra & Steinmann, 2018: 19; Sahagún-Godínez et al., 2014: 184-185). 10 m. Endemic.

Cnidoscolus tepiquensis (M. M. Constantin et Gallaud) R. McVaugh, Bulletin of the Torrey Botanical Club 71(5): 466. 1944. (Breckon, 1975: 299-311; Maya-Lastra & Steinmann, 2018: 20). 20 m. Endemic.

Cnidoscolus tubulosus (J. Müller) I. M. Johnston, Contributions from the Gray Herbarium of Harvard University 68: 86. 1923. (González, 2010: 321; Breckon, 1975: 387-402; Fernández-Casas 2014: 27-31; Maya-Lastra & Steinmann, 2018: 20-21; Parker, 2008: 268). Cnidoscolus jurgensenii is considered a synonym. 5(-8) m (mostly shrubby).

Croton arboreus C. F. Millspaugh, Publications of the Field Columbian Museum, Botanical Series 1(3): 303. 1896. 10(-15) m (sometimes shrubby). Endemic.

Croton axillaris J. Müller, Linnaea 34: 126. 1865. (González, 2010: 326; Parker, 2008: 270). 5 m.

Croton billbergianus J. Müller, Linnaea 34: 98. 1865. (Caruzo & Cordeiro, 2013: 21; González, 2010: 326-327; Parker, 2008: 273; Webster, 2001a: 355). Two subspecies, 1 in Mexico (Webster, 2001a: 355). 12 m (20 m in Costa Rica).

Croton carpostellatus B. L. León et M. Martínez, Novon 18(2): 189. 2008. 6 m. Endemic.

Croton draco D. F. von Schlechtendal et L. K. von Chamisso, Linnaea 6: 360. 1831. (González, 2010: 328; Parker, 2008: 271; Pennington & Sarukhán, 2005: 312-313; Rzedowski, 2015: 122; Webster, 2001a: 356). 18 m.

Croton glabellus C. Linnaeus, Systema naturae (editio decima) 2: 1275. 1759. (Parker, 2008: 271; van Ee et al., 2011). Two varieties, 1 in Mexico (van Ee et al., 2011). 20 m.

Croton gomezii G. L.Webster, Lundellia 8: 13. 2005. 7 m. Endemic.

Croton guatemalensis J. P. Lotsy, Botanical Gazette 20(8): 353. 1895. (Croizat, 1942: 447-448; Parker, 2008: 271-272; Webster, 2001a: 360-361). 15 m.

Croton icche C. L. Lundell, Phytologia 1(12): 404. 1940. 20 m.

Croton lasiopetaloides L. Croizat, Publications of the Field Museum of Natural History, Botanical Series 22(8): 450. 1942. 15 m.

Croton lindquistii V. W. Steinmann, Phytotaxa 166(3): 236. 2014. (As Croton fantzianus in Felger et al., 2001: 147-148; Webster, 2001a: 360; as Croton aff. niveus in Steinmann & Felger, 1997: 22). 7 m. Endemic.

Croton mayanus B. L. León et H. Vester, Novon 16(4): 505. 2006. 10 m. Endemic.

Croton nitens O. Swartz, Nova Genera et Species Plantarum seu Prodromus 100. 1788. (van Ee et al., 2011). 10 m (sometimes shrubby).

Croton niveus N. J. von Jacquin, Enumeratio Systematica Plantarum, quas in insulis Caribaeis 32. 1760. (González, 2010: 331-332; Parker, 2008: 272; Webster, 2001a: 359). 12 m.

Croton nubigenus G. L. Webster, Madroño 35: 117. 1988. (Álvarez-Jiménez et al., 2019: 849). 12 m.

Croton oerstedianus J. Müller, Linnaea 34: 105. 1865. (Parker, 2008: 272). 8 m.

Croton pascualii E. J. Lott et M. Martínez, Lundellia 15: 54. 2012. 6 m (often smaller and shrubby). Endemic.

Croton pseudoglabellus C. L. Lundell, Phytologia 1(12): 407. 1940. 8 m. Endemic.

Croton pseudoniveus C. L. Lundell, Phytologia 1(14): 449. 1940. (Webster, 2001a: 360). 6 m.

Croton reflexifolius K. S. Kunth, A. J. A. Bonpland et F. W. H. A. von Humboldt, Nova genera et species plantarum (editio quarta) 2: 68. 1817. (Martínez-Gordillo & Ginez-Vázquez, 2014: 59-61; Parker, 2008: 273; Webster, 2001a: 361). 10 m.

Croton rosarianus M. Martínez et R. Cruz, Anales del Instituto de Biología de la Universidad Nacional Autónoma de México, Botánica 73(2): 138. 2002. 8 m. Endemic.

Croton schiedeanus D. F. von Schlechtendal, Linnaea 19: 243. 1847[1846]. (González, 2010: 333-334; Parker, 2008: 273-274; Webster, 2001a: 359). 20(-25) m.

Croton sousae M. Martínez et R. Cruz, Anales del Instituto de Biología de la Universidad Nacional Autónoma de México, Botánica 73(2): 142. 2002. 20 m. Endemic.

Croton tabacensis C. L. Lundell, Phytologia 1(12): 408. 1940. 7 m. Endemic.

Croton xalapensis K. S. Kunth, A. J. A. Bonpland et F. W. H. A. von Humboldt, Nova genera et species plantarum (editio quarta) 2: 85. 1817. (González, 2010: 336-337; Parker, 2008: 274; Webster, 2001a: 356). 8 m.

Enriquebeltrania crenatifolia (F. Miranda) J. Rzedowski, Boletín de la Sociedad Botánica de México 38: 75. 1979[1980]. 5(-8) m (often shrubby). Endemic.

Enriquebeltrania disjuncta A. De-Nova et V. Sosa, Systematic Botany 31(3): 542. 2006. 6 m (usually shrubby). Endemic.

Euphorbia calcarata (D. F. von Schlechtendal) V. W. Steinmann, Acta Botanica Mexicana 65: 48. 2003. (Dressler, 1957: 104-109; Olson et al., 2005: 639-640). Pedilanthus calcaratus is considered a synonym. 7 m.

Euphorbia calyculata K. S. Kunth, A. J. A. Bonpland et F. W. H. A. von Humboldt, Nova genera et species plantarum (editio quarta) 2: 59. 1817. (Dorsey et al., 2013: 307). 12 m. Endemic.

Euphorbia coalcomanensis (L. Croizat) V. W. Steinmann, Acta Botanica Mexicana 65: 48. 2003. (Dressler, 1957: 112-115; Olson et al., 2005: 639-640). 7 m. Endemic.

Euphorbia cotinifolia C. Linnaeus, Species Plantarum 2: 453. 1753. (González, 2010: 350-351; Parker, 2008: 276). 10 m (often not as tall and shrubby).

Euphorbia lundelliana L. Croizat, American Midland Naturalist 29(2): 476. 1943. (Dorsey et al., 2013: 305). 25 m. Endemic.

Euphorbia macvaughii S. Carvajal et J. A. Lomelí, Phytologia 49: 189. 1981. 5 m (often smaller and shrubby). Endemic.

Euphorbia pulcherrima C. L. von Willdenow ex J. F. Klotzsch, Allgemeine Gartenzeitung 2(4): 27. 1834. (González, 2010: 357; Lack, 2011; Mayfield, 1997: 217-224; Parker, 2008: 277). 10 m (often not as tall and shrubby; cultivated generally less than 1 m).

Euphorbia schlechtendalii P. E. Boissier, Centuria Euphorbiarum 18. 1860. (González, 2010: 357-358; Parker, 2008: 277-278; Sahagún-Godínez et al., 2014: 185-186). 10 m (often not as tall and shrubby).

Euphorbia tanquahuete M. Sessé et J. M. Mociño, Flora Mexicana. 122. 1894. (Dorsey et al., 2013: 305; Sahagún-Godínez et al., 2014: 186-187). 25 m. Endemic.

Euphorbia tresmariae (C. F. Millspaugh) P. C. Standley, Contributions from the United States National Herbarium 23(3): 601. 1923. 6 m (usually smaller and often shrubby). Endemic.

Garcia nutans M. Vahl, Skrifter af Naturhistorie-Selskabet 2(1): 217. 1792. (González, 2010: 360-361; Parker, 2008: 278; Rzedowski, 2015: 165). 15 m.

Garcia parviflora C. L. Lundell, Wrightia 1(1): 6. 1945. 15 m. Endemic.

Gymnanthes actinostemoides J. Müller, Linnaea 32: 103. 1863. 20 m. Endemic.

Gymnanthes insolita R. S. Ferris, Contributions from the Dudley Herbarium 1(2): 75. 1927. 5 m. Endemic.

Gymnanthes longipes J. Müller, Linnaea 34: 216. 1865. 18 m. Endemic.

Gymnanthes lucida O. Swartz, Nova Genera et Species Plantarum seu Prodromus 96. 1788. (Parker, 2008: 279; Rzedowski, 2015: 171; Wurdack, 2016: 228). 19 m.

Gymnanthes riparia (D. F. von Schlechtendal) J. F. Klotzsch, Archiv für Naturgeschichte 7: 182. 1841. (González, 2010: 361; Parker, 2008: 279). 20 m (25 m in Costa Rica).

Hippomane mancinella C. Linnaeus, Species Plantarum 2: 1191. 1753. (González, 2010: 364; Parker, 2008: 281). 10(-18) m.

Hura polyandra H. E. Baillon, Étude générale du groupe des Euphorbiacées 543. 1858. (Felger et al., 2001; 149; Parker, 2008: 282; Pennington & Sarukhán, 2005: 314-315). 20(-30) m.

Jatropha alamanii J. Müller, Linnaea 34: 207. 1865. (Dehgan, 2012: 174-175). 7 m. Endemic.

Jatropha bartlettii R. L. Wilbur, Journal of the Elisha Mitchell Scientific Society 70: 99. 1954. (Dehgan, 2012: 163-165). 7 m. Endemic.

Jatropha cinerea J. Müller. Prodromus systematis naturalis regni vegetabilis 15(2.2): 1079. 1866. (Dehgan, 2016: 202-203). Jatropha canescens is considered a synonym. 5 m (usually shrubby).

Jatropha chamelensis L. A. Pérez, Boletín de la Sociedad Botánica de México 42: 35. 1982. (Dehgan, 2012: 165-168). 10 m. Endemic.

Jatropha cordata (C. G. de Ortega) J. Müller in A. P. de Candolle, Prodromus Systematis Naturalis Regni Vegetabilis 15(2): 1078. 1866. (Dehgan, 2012: 203-206; Felger et al., 2001: 150-151; Sahagún-Godínez et al., 2014: 187-188; Steinmann & Felger, 1997: 58). 10(-13) m. Endemic.

Jatropha curcas C. Linnaeus, Species Plantarum 2: 1006. 1753. (Dehgan, 2012: 151-158; Dehgan, 2016: 202; González, 2010: 366-367; Guevara-Fefer et al., 2016: 91-100; Parker, 2008: 283). 15 m.

Jatropha dehganii J. Jiménez, Acta Botanica Mexicana 30: 5. 1995. (Dehgan, 2012: 210-212). 5 m (often smaller and shrubby). Endemic.

Jatropha elbae J. Jiménez, Cactáceas y Suculentas Mexicanas 31(1): 3. 1986. (Dehgan, 2012: 233-235). 8 m. Endemic.

Jatropha galvanii J. Jiménez et L. M. Contreras, Cactáceas y Suculentas Mexicanas 26(1): 3. 1981. (Dehgan, 2012: 198-201). 8 m. Endemic.

Jatropha gaumeri J. M. Greenman, Publications of the Field Columbian Museum, Botanical Series 2(6): 256. 1907. (Parker, 2008: 283; Dehgan, 2012: 194-196). 10 m.

Jatropha malacophylla P. C. Standley, Proceedings of the Biological Society of Washington 37: 45. 1924. (Dehgan, 2012: 158-159; Felger et al., 2001: 151-152; Steinmann & Felger, 1997: 59). 7 m. Endemic.

Jatropha mcvaughii B. Dehgan et G. L. Webster, Madroño 25(1): 36. 1978. (Dehgan, 2012: 160-161). 6 m (often smaller and shrubby). Endemic.

Jatropha peltata V. de Cervantes, Gazeta de literatura de México 3(Suppl.): 3. 1794. (Dehgan, 2012: 171-174). Jatropha platyphylla is considered a synonym. 10 m. Endemic.

Jatropha pereziae J. Jiménez, Acta Botanica Mexicana 30: 2. 1995. (Dehgan, 2012: 168-169). 10 m. Endemic.

Jatropha pseudocurcas J. Müller, Linnaea 34: 208. 1865. (Dehgan, 2012: 177-179, 181-182; Jiménez-Ramírez & Vega-Flores, 2014: 72-74). Jatropha andrieuxii is considered a synonym. 6 m. Endemic.

Jatropha riojae F. Miranda, Anales del Instituto de Biología de la Universidad Nacional Autónoma de México, Botánica 13: 456. 1942. (Dehgan, 2012: 209-210). 7 m. Endemic.

Jatropha rufescens T. S. Brandegee, University of California Publications in Botany 4: 88. 1910. (Dehgan, 2012: 179; Jiménez-Ramírez & Vega-Flores, 2014: 73-75). 10 m. Endemic.

Jatropha sotoi-nunyezii F. J. Fernández et E. Martínez, Fontqueria 55(62): 471. 2008. (Dehgan, 2012: 237-240; Guevara-Fefer et al., 2016: 91-100). 5 m. Endemic.

Jatropha stephani J. Jiménez et M. Martínez, Anales del Instituto de Biología de la Universidad Nacional Autónoma de México, Botánica 61(1): 1. 1991. (Dehgan, 2012: 168-171). 10 m. Endemic.

Jatropha sympetala S. F. Blake et P. C. Standley, Proceedings of the Biological Society of Washington 33: 118. 1920. (Dehgan, 2012: 206, 207-209, 212-213; as Jatropha standleyi in Pennington & Sarukhán, 2005: 316-317). Jatropha ortegae is considered a synonym. 10 m. Endemic.

Mabea excelsa P. C. Standley et J. A. Steyermark, Publications of the Field Museum of Natural History, Botanical Series 23(3): 123. 1944. (González, 2010: 368; Martínez-Gordillo et al., 2000: 89-93; Parker, 2008: 284). 15(-30) m.

Mabea occidentalis G. Bentham, Hooker’s Journal of Botany and Kew Garden Miscellany 6: 364. 1854. (González, 2010: 369; Martínez-Gordillo et al., 2000: 89-93; Parker, 2008: 284-285). 15 m.

Mabea tenorioi M. Martínez, J. Jiménez et R. Cruz, Anales del Instituto de Biología de la Universidad Nacional Autónoma de México, Serie Botánica 71(2): 93. 2000. 6 m. Endemic.

Manihot aesculifolia (K. S. Kunth, A. J. A. Bonpland et F. W. H. A. von Humboldt) J. B. E. Pohl, Plantarum Brasiliae Icones et Descriptiones 1: 55. 1827. (Felger et al., 2001: 15; González, 2010: 370-371; Parker, 2008: 285; Rogers & Appan, 1973: 39-45; Steinmann & Felger, 1997: 59). 8 m (usually smaller and shrubby).

Manihot auriculata R. McVaugh, Brittonia 13: 190. 1961. (Rogers & Appan, 1973: 39-40). 6 m. Endemic.

Manihot caudata J. M. Greenman, Proceedings of the American Academy of Arts and Sciences 32: 82. 1903. (Rogers & Appan, 1973: 68-70; Sahagún-Godínez et al., 2014: 188-189; as Manihot sp. in Steinmann & Felger, 1997: 60-61). 10 m. Endemic.

Manihot crassisepala F. Pax et K. Hoffmann in H. G. A. Engler, Das Pflanzenreich IV 147 II(44): 28. 1910. (Rogers & Appan, 1973: 74, 76-77). 15 m (mostly smaller). Endemic.

Manihot foetida (K. S. Kunth, A. J. A. Bonpland et F. W. H. A. von Humboldt) J. B. E. Pohl, Plantarum brasiliae icones et descriptiones 1: 55. 1827. (Rogers & Appan, 1973: 74-75). 10 m. Endemic.

Manihot michaelis R. McVaugh, Brittonia 13: 190. 1961. (Rogers & Appan, 1973: 70-71). 10 m. Endemic.

Manihot oaxacana D. J. Rogers et S. G. Appan, Flora Neotropica Monograph 13: 46. 1973. 5 m (usually smaller and often shrubby). Endemic.

Manihot rubricaulis I. M. Johnston, Contributions from the Gray Herbarium of Harvard University 68: 90. 1923. (Rogers & Appan, 1973: 44-47; Steinmann & Felger, 1997: 60). Manihot rubricaulis subsp. isoloba is considered a synonym. 5 m (sometimes smaller and shrubby). Endemic.

Manihot tomatophylla P. C. Standley, American Midland Naturalist 36(1): 178. 1946. (Rogers & Appan, 1973: 70-73). 10 m. Endemic.

Manihot websteri D. J. Rogers et S. G. Appan, Flora Neotropica Monograph 13: 72. 1973. 9 m. Endemic.

Omphalea oleifera H. B. Hemsley, Pharmaceutical Journal and Transactions 13: 301. 1882. (Gillespie, 1988: 227-233; González, 2010: 373; Parker, 2008: 287; Pennington & Sarukhán, 2005: 318-319). 30(-35) m.

Pleradenophora lottiae (R. McVaugh) A. L. Melo et H. J. Esser, Phytotaxa 81(1): 33. 2013. Sebastiania lottiae is considered a synonym. 12 m. Endemic.

Pleradenophora tikalana (C. L. Lundell) A. L. Melo et H. J. Esser, Phytotaxa 81(1): 35. 2013. (As Sebastiania cornuta in Felger et al. 2001: 153-154; Steinmann & Felger, 1997: 63-64). Sebastiania tikalana is also considered a synonym. 9 m.

Pleradenophora tuerckheimiana (F. Pax et K. Hoffmann) A. L. Melo et H. J. Esser, Phytotaxa 81(1): 35. 2013. (Parker, 2008: 292). Sebastiania tuerckheimiana, S. confusa, and S. longicuspis are considered synonyms. 18 m.

Sapium glandulosum (L.) T. Morong, Annals of the New York Academy of Sciences 7: 227. 1893. (González, 2010: 388; Kruijt, 1996: 44-50; Parker, 2008: 291). 25 m (30 m in Costa Rica).

Sapium lateriflorum W. B. Hemsley, Icones plantarum 27. 1901. (Kruijt, 1996: 57-59; Parker, 2008: 291). Sapium nitidum is considered a synonym. 20(-30) m.

Sapium macrocarpum J. Müller, Linnaea 32: 119. 1863. (González, 2010: 389; Kruijt, 1996: 65-67; Parker, 2008: 291). 30 m (35 m in Costa Rica).

Sebastiania appendiculata (J. Müller) E. Jablonszky, Phytologia 16: 423. 1968. Sapium appendiculatum is a synonym. 10(-16) m. Endemic.

Sebastiania chiapensis C. L. Lundell, Wrightia 4(1): 35. 1968. 9 m. Endemic.

Sebastiania cruenta (P. C. Standley et J. A. Steyermark) F. Miranda, Anales del Instituto de Biología de la Universidad Nacional de México 24: 64. 1953. 10(-15) m.

Sebastiania glandulosa (O. Swartz) J. Müller in A. P. de Candolle, Prodromus systematis naturalis regni vegetabilis 15(2): 1186. 1866. (Parker, 2008: 292). Sebastiania adenophora is considered a synonym. 15 m.

Sebastiania hintonii C. L. Lundell, Wrightia 2(2): 105. 1960. Sebastiania jaliscensis is considered a synonym. 10 m. Endemic.

Sebastiania pavoniana (J. Müller) J. Müller in A. P. de Candolle, Prodromus systematis naturalis regni vegetabilis 15(2): 1189. 1866. (Felger et al. 2001: 154-155; González, 2010: 390; Sahagún-Godínez et al., 2014: 190-191; Steinmann & Felger, 1997: 64). Sebastiania palmeri and S. pringlei are considered synonyms. 15 m.

Stillingia acutifolia (G. Bentham) G. Bentham ex W. B. Hemsley. Biologia centrali-americana […] Botany 3(15): 135. 1883. (Parker, 2008: 293; Rogers, 1951: 243-244). 9 m.

Stillingia sanguinolenta J. Müller. Linnaea 32: 88. 1863. (Rogers, 1951: 224-226). 7 m.

Tetrorchidium brevifolium P. C. Standley et J. A. Steyermark, Publications of the Field Museum of Natural History, Botanical Series 23(3): 126. 1944. (Parker, 2008: 293-294). 21 m.

Tetrorchidium rotundatum P. C. Standley, Tropical Woods 16: 44. 1928. (González, 2010: 392; Parker, 2008: 294). 45 m.

Peraceae

Pera barbellata P.C. Standley, Publications of the Field Museum of Natural History, Botanical Series 8(1): 19. 1930. (Parker, 2008: 287-288). 20 m.

Phyllanthaceae

Astrocasia peltata P. C. Standley, Contributions from the Dudley Herbarium 1: 74. 1927. (Calderón-Sanoa, 2014: 165-168; Webster, 1992: 318-319). 5 m.

Astrocasia tremula (A. H. Grisebach) G. L. Webster, Journal of the Arnold Arboretum 39: 208. 1958. (González, 2010: 315; Parker 2008: 265; Webster 1992: 319-321). 10 m (frequently smaller).

Hieronyma alchorneoides Allemão, Hieronima alchorneoides (Typographis do Archivo medico brasileiro) 1-2. 1848. (Franco-Rosselli, 1990: 317-323; González, 2010: 363; Parker 2008: 280; Webster, 2001b: 886). Two varieties (González, 2010), 1 in Mexico. 40 m (over 60 m in Costa Rica).

Hieronyma oblonga (L. F. Tulasne) J. Müller, Linnaea 34: 66. 1865. (Franco-Rosselli 1990: 323-327; González, 2010: 363-364; Parker, 2008: 280-281; Webster, 2001b: 886-887). 25 m. (40 m in Costa Rica).

Margaritaria nobilis C. Linnaeus filius, Supplementum plantarum 428. 1781[1782]. (González, 2010: 371-372; Parker 2008: 286; Webster, 1979: 412-415; Webster, 2001c: 891-892). 20 m.

Phyllanthus acuminatus M. Vahl, Symbolae botanicae 2: 95. 1791. (González, 2010: 377-378; Parker, 2008: 289; Webster, 2001a: 382; Webster, 2001d: 896). 8 m (frequently smaller, but 15 m in Costa Rica).

Phyllanthus botryanthus J. Müller in A. L. P. de Candolle, Prodromus systematis naturalis regni vegetabilis 15(2): 323. 1866. (Webster, 2001a: 383). 8 m (frequently smaller).

Phyllanthus elsiae I. Urban, Repertorium specierum novarum regni vegetabilis 15: 405-406. 1919. (Webster, 2001a: 381; Webster, 2001d: 897-898). 15 m.

Phyllanthus grandifolius C. Linnaeus, Species plantarum 2: 981. 1753. (Parker, 2008: 289; Steinmann, 2007: 16-18). 9 m.

Phyllanthus mocinianus H. E. Baillon, Adansonia 1: 35. 1860. (Webster, 2001a: 383; Steinmann, 2007: 21-24). 5 m.

Phyllanthus tuerckheimii G. L. Webster, Annals of the Missouri Botanical Garden 54(2): 195-196. 1967. 8 m (frequently smaller).

Savia sessiliflora (O. P. Swartz) C. L. von Willdenow, Species plantarum (editio quarta) 4(2): 771. 1805[1806]. (Rzedowski, 2015: 315; Steinmann, 2007: 30-33). 10 m.

Picrodendraceae

Piranhea mexicana (P. C. Standley) A. Radcliffe-Smith, Kew Bulletin 51: 546. 1996. (Pennington & Sarukhán, 2005: 320-321). 25 m. Endemic.

Putranjivaceae

Drypetes brownii P. C. Standley, Tropical Woods 20: 20. 1929. (González, 2010: 344; Levin, 2001: 878; Parker, 2008: 275). 25 m. (30 m in Costa Rica).

Drypetes gentryi [as gentryii by]  J. A. Monachino, Phytologia 3: 32. 1948. (Felger et al., 2001; 148-149; Levin, 2013: 83-84; Steinmann & Felger, 1997: 28). 30 m. Endemic.

Drypetes lateriflora (O. P. Swartz) C.W.L. Krug & I. Urban, Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 15(1): 357. 1892. (González, 2010: 344; Levin, 2001: 878; Levin, 2016: 269-270; Parker, 2008: 275; Rzedowski, 2015:134; Steinmann, 2001: 2-5). 20 m.

Urticaceae

Boehmeria caudata O. Swartz, Nova genera et species plantarum seu prodromus 34. 1788. (Parker, 2008: 933; Pool, 2001: 2481; Wilmot-Dear & Friis, 1996: 21-26; Wilmot-Dear et al., 2015: 120). 9 m.

Boehmeria pavonii H. A. Weddell, Annales des Sciences Naturelles, Botanique, série 4-1: 202. 1854. (Parker, 2008: 933; Wilmot-Dear & Friis, 1996: 43-44; Wilmot-Dear et al., 2015: 121). 8 m.

Boehmeria radiata W. C. Burger, Phytologia 31(3): 267. 1975. (Wilmot-Dear & Friis, 1996: 51-53; Wilmot-Dear et al., 2015: 122). 3(-15) m.

Boehmeria ulmifolia H. A. Weddell, Annales des Sciences Naturelles; Botanique, série 4-1: 202. 1854. (Parker, 2008: 933; Pool, 2001: 2482; Steinmann, 2005: 7-8; Wilmot-Dear & Friis, 1996: 48-51; Wilmot-Dear et al., 2015: 122-123). 5(-13) m.

Cecropia angustifolia A. A. Trécul, Annales des Sciences Naturelles, Botanique, série 3-8: 83. 1847. (Berg & Franco-Rosselli, 2005: 51, 54-63; Berg, 2015: 123-124). 25 m.

Cecropia obtusifolia A. Bertoloni, Novi commentarii academiae scientiarum instituti bononiensis 4: 439. 1840. (Berg & Franco-Rosselli, 2005: 48, 128-135; Berg, 2015: 125-126; Parker, 2008: 149-150; Pennington & Sarukhán, 2005: 156-157; Rzedowski, 2015: 94; Steinmann, 2009: 5-8; Stevens, 2001: 594). 12(-35) m.

Cecropia peltata C. Linnaeus, Systema naturae (editio decima) 2: 1286. 1759. (Berg & Franco-Rosselli, 2005: 70, 142-149; Berg, 2015: 126; Parker, 2008: 150; Stevens, 2001: 594). 15(-25) m.

Coussapoa oligocephala J. Donnell, Botanical Gazette 40(1): 11. 1905. (Berg et al., 1990: 13, 77, 79-80; Berg, 2015: 129; Parker, 2008: 151). 30 m.

Coussapoa purpusii P. C. Standley, Publications of the Field Museum of Natural History, Botanical Series 8(1): 6. 1930. (Berg et al., 1990: 13, 90-91; Berg, 2015: 130; Parker, 2008: 151). 20 m.

Discocnide mexicana (F. M. Liebmann) W. L. Chew, Gardens’ Bulletin, Singapore 21(2): 208. 1965. (Monro, 2015a: 131; Parker, 2008: 934; Pool, 2001: 2482; Rzedowski, 2015: 132; Steinmann, 2005: 9-12; Steinmann, 2009: 9-11). 10 m.

Gyrotaenia microcarpa (H. A. Weddell) W. Fawcett & A. B. Rendle, Flora of Jamaica 3: 56. 1914. (Monro, 2015b: 131). 8 m.

Myriocarpa bifurca F. M. Liebmann, Det Kongelige Danske videnskabernes selskabs skrifter; Naturvidenskabelig og mathematisk afdeling. 2: 307. 1851. (Monro, 2009: 87; Monro, 2015c: 133; Pool, 2001: 2483; Steinmann, 2009: 11-13). Myriocarpa brachystachys is considered a synonym. 8 m.

Myriocarpa cordifolia F. M. Liebmann, Det Kongelige Danske videnskabernes selskabs skrifter; Naturvidenskabelig og mathematisk afdeling. 2: 306. 1851. (Monro, 2009: 87-88; Monro, 2015c: 133-134). 12 m.

Myriocarpa cubilgueitzensis A. K. Monro, Novon 19(1): 88. 2009. (Monro, 2009: 88-90; Monro, 2015c: 134). 9 m.

Myriocarpa heterospicata J. Donnell, Botanical Gazette 12(6): 133. 1887. (Monro, 2009: 90; Monro, 2015c: 134; Parker, 2008: 935; Pool, 2001: 2483). 9 m.

Myriocarpa longipes F. M. Liebmann, Det Kongelige Danske videnskabernes selskabs skrifter; Naturvidenskabelig og mathematisk

afdeling 2: 306. 1851. (Monro, 2009: 90-92; Monro, 2015c: 134-135; Parker, 2008: 150; Pool, 2001: 2483; Steinmann, 2005: 19-20). 12 m.

Myriocarpa obovata J. Donnell, Botanical Gazette 46(2): 117. 1908. (Monro, 2009: 92-93; Monro, 2015c: 135; Parker, 2008: 935; Pool, 2001: 2484). 17 m.

Myriocarpa trifurca A. K. Monro, Novon 19(1): 93. 2009. (Monro, 2015c: 135). 6 m. Endemic.

Phenax mexicanus H. A. Weddell, Annales des Sciences Naturelles, Botanique, série 4-1: 193. 1854. (Monro, 2015d: 137; Parker, 2008: 935-936; Steinmann, 2009: 16-19). 10 m.

Pourouma bicolor C. F. von Martius, Systema materiae medicae vegetabilis brasiliensis 34. 1843. (Berg et al., 1990: 132-144; Berg, 2015: 161; Parker, 2008: 152; Pennington & Sarukhán, 2005: 158-159; Stevens, 2001: 596). Five subspecies, 1 in Mexico (Berg, 2015). Pourouma aspera is considered a synonym of subspecies bicolor, which does not exist in Mexico. 30 m.

Urera baccifera (C. Linnaeus) C. Gaudichaud ex H. A. Weddell, Annales des Sciences Naturelles; Botanique, sér. 3 18: 199. 1852. (Monro & Rodríguez-González, 2009: 270-271; Monro, 2015e: 166-167; Parker, 2008: 936-937; Pool, 2001: 2493). 10 m.

Urera corallina (F. M. Liebmann) H. A. Weddell, Prodromus systematis naturalis regni vegetabilis 16(1): 90. 1869. (Felger et al., 2001: 330-331; Monro & Rodríguez-González, 2009: 271-273; Monro, 2015e: 167; Parker, 2008: 936; Pool, 2001: 2493-2494; Steinmann, 2005: 50-52). Urera corallina has often been treated as a synonym of U. caracasana, but they are considered here distinct species (see justification in Pool, 2001; Steinmann, 2005). Urera caracasana does not exist in Mexico. Urera corallina has also been confused with U. alceifolia and U. elata, species that also do not occur in Mexico. 10 m (15 m in Nicaragua).

Urera glabriuscula V. W. Steinmann, Acta Botanica Mexicana 71: 22. 2005. (Monro & Rodríguez-González, 2009: 276; Monro, 2015e: 137). 10 m.

Urera pacifica V. W. Steinmann, Acta Botanica Mexicana 71: 28. 2005. 8 m. Endemic.

Urera rzedowskii V. W. Steinmann, Acta Botanica Mexicana 71: 33. 2005. Although treated as a synonym of Urera simplex by Monro & Rodríguez-González (2009: 281), it is here maintained as a distinct species. 13 m.

Urera simplex H. A. Weddell, Prodromus systematis naturalis regni vegetabilis 16(1): 90. 1869. (Monro & Rodríguez-González, 2009: 281-282; Monro, 2015e: 170-171; Parker, 2008: 938; Pool, 2001: 2494; Rzedowski, 2015: 348). Urera tuerckheimii is considered a synonym. 10 m.

Urera verrucosa (F. M. Liebmann) V. W. Steinmann, Acta Botanica Mexicana 71: 39. 2005. (Monro & Rodríguez-González, 2009: 282; Monro, 2015e: 171; Steinmann, 2005: 56-58). 10(-30) m.

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