C. E. Bessey 1907: 323 (as "Gnetales" Hoogland and Reveal, 2005) [M. J. Donoghue, J. A. Doyle, and P. D. Cantino], converted clade name

Registration Number: 47 and Donoghue, 1986; Doyle, 1996), compound microsporangiate strobili, striate pollen (modi- The smallest crown clade contain- fied to echinate in ; Yao et al., 2004), Definition: with Linnaeus 1767, di tube, and meristem Gnetum gnemon micropylar apical ing mirabilis one tunica layer (Doyle and Donoghue, 1986, Linnaeus 1753, and tachya Serbet, 1994; 1862. This is a minimum-crown- 1992; Crane, 1988; Rothwell and 1. D. Hooker definition: min dade definition. Abbreviated Doyle, 2006). Linnaeus 1767 & crown V (Gnetum gnemon Welwitschia and Gnetales (see Ephedra distachya Linnaeus 1753 & Synonyms: Gnetopsida mirabilis J. D. Hooker 1862). Comments); also Gnetidae (Chase and Reveal, four 2009) and Gnetatae (Kubitzki, 1990). All with the same Etymology: Derived from Gnetum (the name are approximate synonyms of an included genus) and the Greek phyto, composition. meaning . The name Gnetum is appar- Comments: The of Gnetophyta is derived from the same word as the specific monophyly ently both molecular and the vernacu- strongly supported by epithet gnemon (i.e., genemo, very Molucca analyses (Crane, 1985, 1988; lar name for Gnetum gnemon in the morphological and 1986, 1992; Doyle et Islands; Markgraf, 1951). Doyle Donoghue, al., 1994; Rothwell and Serbet, 1994; Doyle, 1996, 2006; Rydin et al., 2002; Soltis et al., Reference Phylogeny: The primary reference also2002; and Mathews, 2004; Hilton is et al. (2002: Fig. 1). See Burleigh phylogeny Rydin 2010, 2011; Lu Hou et al. (2015: Fig. 2). and Bateman, 2006; Zhong, et The names et al., 2014; Wickett al., 2014). and Gnetales are m Gnetopsida, widely Composition: Ephedra (40 species), Gnetophyta, to this clade (Gnetidae and Gnetatae and Welwitschia applied 50species), (1 species) (species much less frequently). Here and previously numbers from 2008). For Mabberley, descrip we have for the tions of these three taxa, see Kubitzki (1990). (Cantino et al., 2007), opted name Gnetales is -phyta ending even though the used, because, although -phyta Synapomorphies more frequently Diagnostic Apomorphies: the rank of phylum (divi- cative to other crown clades include mu is used to designate nomenclature, it tiple axillary buds, opposite phyllotaxy, er- sion) in botanical rank-based whereas and -ales nal ovules with one or two outer envelopes also means "," -opsida other than rank. ELVd from opposite primordia, basally fused have no meaning indicating microsporophylls with terminal microspo dngla, vessels in xylem (assuming these are Literature Cited homologous with angiosperm vessels, as of Univ E. 1907. A synopsis plant phyla. inferred in Bessey, C. even in: analyses which giosperms 7:275-373. and Stud., University of Nebraska, gnetophytes are exta sister groups: Doyle Gnetophyta

Burleigh, J. G., and S. Mathews. 2004. Phylogenetic Lu, Y., J.-H. Ran, D.-M. Guo, Z.-Y. Yang, and signal in nucleotide data from seed plants: X.-Q. Wang. 2014. Phylogeny and diver- implications for resolving the seed plant tree of gence times of inferred from life. Am. J. Bot. 91:1599-1613. single-copy nuclear genes. PLOS ONE Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. 99):e107679. Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis, Mabberley, D. J. 2008. Mabberley's Plant-Book. 3rd and M. J. Donoghue. 2007. Towards a phylo- edition. Cambridge University Press, Cambridge, genetic nomenclature of Tracheophyta. Taxon UK. 56:822-846 and E1-E44. Markgraf, F. 1951. Gnetaceae. Pp. 336-347 in Flora Chase, M. W., and J. L. Reveal. 2009. A phyloge Malesiana, Series 1, Vol. 4(3). (C. G. G. J. van netic classification of the land plants to accom- Steenis, ed.). Noordhof-Kolf, Djakarta. pany APG III. Bot. J. Linn. Soc. 161:122-127. Rothwell, G. W., and R. Serbet. 1994. Lignophyte Crane, P. R. 1985. Phylogenetic analysis of seed phylogeny and the evolution of spermato- plants and the origin of angiosperms. Ann. phytes: a numerical cladistic analysis. Syst. Bot Mo. Bot. Gard. 72:716-793. 19:443-482. Crane, PR 1988. Major clades and relationships in the Rydin, C., M. Källersjö, and E. Friis. 2002. Seed "higher gymnosperms. Pp. 218-272 in Origin plant relationships and the systematic position and Evolution of Gymnosperms (C. B. Beck, ed.). of Gnetales based on nuclear and chloroplast Columbia University Press, New York. DNA: conflicting data, rooting problems, and Doyle, J. A. 1996. Seed plant phylogeny and the the monophyly of conifers. Int. J. Plant Sci. relationships of Gnetales. Int. J. Plant Sci. 157 163:197-214. (suppl.):$3-s39. oltis, D. E., P. S. Soltis, and M. J. Zanis. 2002. Doyle, J. A. 2006. Seed and the origin of Phylogeny of seed plants based on evidence angiosperms. J. Torrey Bot. Soc. 133:169-209. from eight genes. Am. J. Bot. 89:1670-1681. Doyle, J. A., and M. J. Donoghue. 1986. Seed plant Wickett, N. J., S. Mirarab, N. Nguyen, T. phylogeny and the origin of angiosperms: an Warnow, E. Carpenter, N. experimental cladistic approach. Bot. Reu Matasci, S. Ayyampalayam, M. S. Barker, J. G. 52:321-431. Burleigh, M. A. Gitzendanner, B. R. Ruhfel, Doyle, J. A., and M. J. Donoghue, 1992. Fossils E. Wafula, J. P. Der, S. W. Graham, S. and seed plant phylogeny reanalyzed. Brittonia Mathews, M. Melkonian, D. E. Soltis, P. 44:89-106. S. Soltis, N. W. Miles, C. J. Rothfels, L. Doyle, J. A., M. J. Donoghue, and E. A. Zimmer. Pokorny, A. J. Shaw, L. DeGironimo, D. 1994. Integration of and ribo- morphological W. Stevenson, B. C. B. somal RNA data on Surek, J. Villarreal, the origin of angiosperms. Roure, H. Philippe, C. W. dePamphilis, T. Ann. Mo. Bot. Gard. 81:419-450. Chen, M. K. Deyholos, R. S. Baucom, T. Hilton, J., and R. M. Bateman. 2006. Pteridosperms M. M. M. are the Kutchan, J. Y. backbone of seed-plant J. Augustin, Wang, Torrey Bot. Soc. 133:119-168. phylogeny. Zhang, Z. Tian, Z. Yan, X. Wu, X. Sun, G. K. Wong, and J. Leebens-Mack. 2014. Hou, C., A. M. Humphreys, O. Thureborn, and C. 2015. New Phylotranscriptomic analysis of the origin Rydin. insights into the and lutionary history of Gnetum (Gnetales). Taxonevo early diversification of land plants. Proc 64:239-252. Natl. Acad. Sci. USA 111:E4859-E4868. Yao, Y., Y. B. Kubitzki, K. 1990. Xi, Geng, and C. Li. 2004. The exine Gnetatae. Pp. 378-391 in Families and ultrastructure of pollen in Gnetum Genera of Vascular Plants, Vol. grains U. (Gnetaceae) from China and its bearing on the 1 (K. Kramer and P. S. vol. Green, eds.). with relationship the ANITA group. Springer-Verlag, Berlin. Linn. Soc. 146:415-425. Bot.

266 Gnetophyta

V. V. D. 7hong, B., 0. Deusch, Goremykin, Penny, James A. Doyle; Department of Evolution and S. V. P. J. Biggs, R. A. Atherton, Nikiforova, Ecology; University of California; Davis, CA and P. J. Lockhart. 2011. Systematic errorin 95616, USA. Email: [email protected]. seed plant phylogenomics. Genome Biol. Evol Philip D. Cantino; Department of Environmental 3:1340-1348. and Plant Biology; Ohio University; Athens, Y. and M. Zhong, B., T Yonezawa, Zhong, OH 45701, USA. Email: [email protected]. Hasegawa. 2010. The position of Gnetales among seed plants: overcoming pitfalls of Date Accepted: 29 August 2011; updated 09 Mol. Biol. chloroplast phylogenomics. Evol February 2018 27:2855-2863. Primary Editor: Kevin de Queiroz Authors

Michael J. Donoghue; Department of Ecology and Evolutionary Biology; Yale University: PO. Box 208106;: New Haven, CT 06520, USA. Email: [email protected].

267 Mesangiosperm_ae M. J. Donoghue, J. A. Doyle, and P. o. cantino in P. D. Cantmo et al. (2007): 834 [M. J. Donoghue, J. A. Doyle, and P. D. Cantine], converted clade name

Registration Number: 65 ascidiate carpels sealed by secretion, compara- ble to those of Amborella trichopoda and other Definition: The largest crown clade contain- members of what Qiu et al. (1999) called the ing Platanus occidentalis Linnaeus 1753 but ''ANITA'' grade (i.e., Amborella, Nymphaeales, not Amborella trichopoda Baillon 1869 and and Austrobaileyales, later extended to include Nymphaea odorata Aiton 1789 (Nymphaeales) Hydatellaceae: Saarela et al., 2007). Most and Austrobaileya scandens C. T. White 1933 molecular analyses have indicated that (Austrobaileyales). This is a maximum-crown- Chloranthaceae and Ceratophyllum are nested clade definition. Abbreviated definition: max within Mesangiospermae, and with some topolo- crown V (Platanus occidentalis Linnaeus 1753 ~ gies (Endress and Doyle, 2009: Fig. 8B) it is Amborella trichopoda Baillon 1869 & Nymphaea equally parsimonious to assume either that pli- odorata Aiton 1789 & Austrobaileya scandens C. cate carpels and sealing by postgenital fusion are T. White 1933). apomorphies at the level of Mesangiospermae, with reversals in some lines, or that these fea- Etymology: Mesangiospermae is a rough trans- tures originated more than once within the lation of"core angiosperms," the informal name clade. However, with other topologies (Soltis et applied to this clade by Judd et al. (2002). The al., 2005: Fig. 3.17) the latter scenario is more prefix mes- (Greek) means "middle" (Stearn, parsimonious. Combined molecular and mor- 1973), and Angjospermae (this volume) is the phological analyses (Doyle and Endress, 2000; name of a larger clade. Endress and Doyle, 2009) and some molecular analyses (Qiu et al., 2005, 2010) supported the Reference Phylogeny: The primary reference placement of Chloranthaceae or a clade con- phylogeny is Qiu et al. (2005: Fig. 2). See also sisting of Chloranthaceae and Ceratophyllum Soltis et al. (2011: Figs. 1, 2) and Wickett et al. as sister to all remaining Mesangjospermae, in (2014: Figs. 2, 3). which case it could be inferred that the ascidi- ate carpels of Chloranthaceae (with or without Composition: Chloranthaceae, Ceratophyllum, Ceratophyllum) are plesiomorphic and plicate Magnoliidae, Monocotyledoneae, and Eudi- carpels sealed by postgenital fusion evolved cotyledoneae (see entries in this volume for the once within Mesangiospermae. In all these last three clades). cases, some homoplasy would remain (e.g., reversals to ascidiate carpels in Nelumbo and Diagnostic Apomorphies: Unambiguous mor- Berberidacaeae; convergent origins of partially phological apomorphies for Mesangiospermae plicate carpels in Jllicium; Doyle and Endress, are not yet known. One possibility is plicate 2000: Fig. 7; Soltis et al., 2005: Fig. 3.17). carpels sealed by pos-tgenital fusion of the Finally, recent embryological studies (Williams margins (see Endress and lgersheim, 2000), and Friedman, 2002; Friedman, 2006) raise the bur this interpretation depends on the place- possibility that the typical ?-celled, 8-nucleate ment of two of the groups of Mesangjospermae, Polygonum-type embryo sac is an apomorphy of Chloranthaceae, and Ceratophyllum, which have Mesangiospermae, assuming that the 9-nucleate Mesangiospermae

embryo sac of Amborella was independently and Eudicotyledoneae) remain unclear. Some derived from the 4-nucleate type found in analyses have suggested that Chloranthaceae Nymphaeales and Austrobaileyales. (e.g., Doyle and Endress, 2000; Qiu et al., 2005: Fig. 1) or a clade comprising Chloranthaceae Synonyms: The informal names "euangio- and Magnoliidae (Saarela et al., 2007: Fig. 2) is sperms" (Qiu et al., 2000) and "core angio- the sister group of the rest of Mesangi,ospermae. sperms" (Judd et al., 2002) are approximate Others have supported Ceratophyllum alone (e.g., synonyms. Zanis et al., 2003: Fig. 4), Monocotyledoneae alone (Qiu et al., 2005: Fig. 2), or a clade consist- Comments: Until we published the name ing of Ceratophyllum and monocots (Qiu et al., Mesangi,ospermae (Camino et al., 2007), there 2005: Fig. 3C; Zanis et al., 2003: Fig. 3) as sister was no preexisting scientific name for this large to the rest (see Soltis et al., 2005, for discussion). and well-supported clade, which includes the In still other analyses Ceratophyllum has been vast majority of living angiosperms. In most linked instead with eudicots (Hilu et al., 2003; recent analyses of the basal angiosperm problem Qiu et al., 2005: Fig. 2; Graham et al., 2006; (e.g., Mathews and Donoghue, 1999; Doyle and Jansen et al., 2007; Moore et al., 2007; Saarela Endress, 2000; Qiu et al., 2000; Zanis et al., 2003; et al., 2007) or with Chloranthaceae (Qiu et al., Xi et al., 2014), which have focused on resolv- 2005: Fig. 3A,B; Qiu et al., 2006: Fig. 3; Qiu et ing relationships among Amborella trichopoda, al., 2010; Endress and Doyle, 2009; Moore et al., Nymphaeales, and Austrobaileyales, the clade com- 2011; Zhang et al., 2012; Zeng et al., 2014). By prising the remaining angiosperms has not been using a maximum-crown-clade definition, and named, with the exception that Qiu et al. (2000: citing all plausible candidates for the extant sister S7) referred to it as "euangiosperms." It did not group among the external specifiers, we ensure receive even an informal name in several phyloge- that all of the major clades of Mesangiospermae netic studies of the angiosperms as a whole (e.g., will be included regardless of their interrelation- Soltis et al., 2000; Hilu et al., 2003) or in summary ships. This definition also ensures that the name treatments (e.g., APG II, 2003; Soltis et al., 2005) Mesangiospermae will still apply to a clade that despite rather high levels of support, though one includes the three major subclades Magnoliidae, text (Judd et al., 2002: 178) referred to the clade Monocotyledoneae, and Eudicotyledoneae in as the "core angiosperms." More recent editions of the unlikely event that Chloranthaceae, Cerato- this text (e.g., Judd et al., 2008, 2016) use the name phyllum, or both are shown to be linked with one Mesangi,ospermae (citing Camino et al., 2007) of the more basal angiosperm clades. as well as "core angiosperms." The Angiosperm Phylogeny Group (APG IV, 2016) used the infor- Literature Cited mal name "Mesangiosperms" in its appendix. Because outgroup relationships are bet- APG II (Angiosperm Phylogeny Group II). 2003. An update of the Angiosperm ter resolved than basal relationships within Phylogeny Group classification for the orders and families Mesangiospermae, compositional stability can be of flowering plants: APG II. Bot. J Linn. Soc. achieved more simply with a maximum-crown- 141 :399-436. clade definition than a minimum-crown-clade APG IV (Angiosperm Phylogeny Group IV). 2016. definition. Relationships among five clades at An update of the Angiosperm Phylogeny the base of Mesangiospermae (Chloranthaceae, Group classification for the orders and fami- Ceratophy/lum, Magnoliidae, Monocotyledoneae, lies of flowering plants: APG IV Bot. J Linn. Soc. 181:1-20.

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292 Tricolpa!ae _M. J. Donoghue, J. A. Doyle, and P. D. Cantmo in P. D. Cantino et al. (2007): E26 [M. J. Donoghue, J. A. Doyle, and P. D. Cantino], converted clade name

the name Registration Number: 108 Comments: Until we published Tricolpatae (Cancino et al., 2007), there was no Definition: The most inclusive clade exhib- scientific name for this clade. Published uses have iring rricolpate (or derivative) pollen grains of the terms "eudicots" and "tricolpates" they refer to svnapomorphic with those found in Platanus not clearly distinguished whether (Eudicotyledoneae). the crown clade or to a more inclusive clade 0.ccidentalis Linnaeus 1753 tricolpate A rricolpate pollen grain is one having three originating with the evolution of paper, we sepa- elongate, furrow-like apertures (colpi) located at pollen. Here, as in our 2007 these names and oriented perpendicular to the equator. This rate the meanings associated with to the is an apomorphy-based definition. Abbreviated by explicitly applying Eudicotyledoneae to the apomorphy- definition: V apo tricolpate pollen [Platanus crown clade and Tricolpatae this distinction occidentalis Linnaeus 1753]. based clade. We think that will be helpful in view of the substantial fossil and the possibility of discover- Etymology: From Greek, tri- (three) and kolpos record of pollen the tricolpate clade that fall (a fold, lap, hollow, or bay, here an elongate lon- ing planes within the eudicot crown. However, if only gitudinal aperture in a pollen grain). outside of extant plants are considered, Eudicotyledoneae have the same composition. Reference Phylogeny: The primary reference and Tricolpatae reference phylogenies and definition phylogeny is Doyle (2005: Fig. 4). See also The comment. The pollen of Illicium and Doyle and Endress (2000: Fig. 4). require Schisandraceae was scored as tricolpate by and Doyle (1989) and then inferred Composition: Eudicotyledoneae (this volume) Donoghue to have evolved separately from the grains of the and stem taxa with tricolpate pollen. So far, all clade. However, these grains differ well-reconstructed Early Cretaceous (Albian) tricolpate standard tricolpate grains in that the colpi fossil taxa with tricolpate pollen (e.g., Friis et al., from 60 degrees from those of the latter 1988; Drinnan et al., 1991; Crane et al., 1993; are located (Huynh, 1976; Doyle et al., 1990) and Mendes et al., 2014; Friis et al., 2017) appear grains fused at the distal pole (syntricolpate). to be pare of the crown group, Eudicotyledoneae usually they were scored as representing a (see Doyle and Endress, 2010), but some dis- Accordingly, by Doyle and Endress (2000) and persed tricolpate pollen types may represent separate state somewhat differently) by Doyle stem taxa that are part of Tricolpatae but not of again (defined Eudicotyledoneae. (2005). In any case, all relevant phylogenetic analyses clearly indicate that the three apertures 11 are not homolo- Diagn ostic. A pomorphies: Tricolpate po en of Illicium and Schisandraceae (see Definition). gous with those of Tricolpatae. Many different forms of pollen grains have evolved (in most cases grains of Synonyms: None (but see Comments). multiple times) from the first tricolpate Tricolpatae

C. L. Hotton, and J. V. Ward. 1990. Doy1 e, J . A ., l l the dade Tricolpatae. These modifications include E rl Cretaceous tecrads, zonasu cu ate pol- increases and decreases in the number of colpi le:, :nd Winteraceae. II. Cladistic analysis and (di-, tetra-, penta-, hexa-, and polycolpate forms). implications. Am. J Bot. 77:1558-1568. Compound-apermrate and porate forms, espe- . A N p R Crane, E. M. Friis, and K. R D nnnan, . ., • · . cially tricolporate and triporate grains, appear to Pedersen. 1991. Angiosperm flowers and tri- have originated frequently, and in some cases the colpate pollen of buxaceous affinity from the position and/or orientation of the colpi or pores Potomac Group (mid-Cretaceous) of eastern has shifted away from the equator of the grain North America. Am. J Bot. 78:153-176. .. E M p R Crane, and K. R. Pedersen. (e.g., polyrugate and polyforate grains). In other Frus, . ., • · 1988. Reproductive structures of Cretaceous cases, apertures have been lost completely (inap- Platanaceae. Biol. Skr. Dan. Vid. Selsk. erturate pollen). The resulting multitude of pol- 31:1-55. len forms all appear to be modifications of the Friis, E. M., K. R. Pedersen, and P.R. Crane. 2017. original grains of Tricolpatae. Kenilanthus, a new eudicot flower with tricol- pate pollen from the Early Cretaceous (early- Literature Cited middle Albian) of eastern North America. Grana 56:161-173. Cancino, P. D., J. A. Doyle, S. W. Graham, W. S. Huynh, K.-L. 1976. L'arrangement du pollen du Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis, genre Schisandra (Schisandraceae) et sa signi- and M. J. Donoghue. 2007. Towards a phylo- fication phylogenique chez les Angiospermes. genetic nomenclature of Tracheophyta. Taxon Beitr. Biol. Pflanz. 52:227-253. 56:822-846 and El-E44. Mendes, M. M., G. W. Grimm, J. Pais, and E. M. Crane, P. R., K. R. Pedersen, E. M. Friis, and A. Friis. 2014. Fossil Kajanthus Lusitanicus gen. et N. Drinnan. 1993. Early Cretaceous (early to sp. nov. from Portugal: floral evidence for Early middle Albian) platanoid inflorescences associ- Cretaceous Lardizabalaceae (Ranunculales, ated with Sapindopsis leaves from the Potomac basal eudicot). Grana 53:283-301. Group of eastern North America. Syst. Bot. 18:328-344. Authors Donoghue, M. J., and J. A. Doyle. 1989. Phylogenetic analysis of angiosperms and Michael J. Donoghue; Department of Ecology and the relationship of Hamamelidae. Pp. 17-45 Evolutionary Biology; Yale University; P.O. in Evolution, Systematics and Fossil History of Box 208106; New Haven, CT 06520, USA. the Hamamelidae, Vol. 1 (P. Crane and S. Email: [email protected]. Blackmore, eds.). Clarendon Press, Oxford. James A. Doyle; Department of Evolution and Doyle, J. A. 2005. Early evolution of angiosperm Ecology; University of California; Davis, CA pollen as inferred from molecular and mor- 95616, USA. Email: [email protected]. phological phylogenetic analyses. Grana Philip D. Cancino; Department of Environmental 44:227-251. and Plant Biology; Ohio University; Athens, Doyle,J. A., and P. K. Endress. 2000. Morphological OH 45701, USA. Email: [email protected]. phylogenetic analysis of basal angiosperms: comparison and combination with molecular data. Int. J. Plant Sci. 161:S121-Sl53. Date Accepted: 27 January 2013; updated 09 Doyle, J. A., and P. K. Endress. 2010. Integrating February 2018 Early Cretaceous fossils into the phylogeny of living angiosperms: Magnoliidae and eudicots. Primary Editor•• Kev1· n d e "·'-<-ue1roz . ]. Syst. Evol. 48:1-35.

312 Eudicotyledonea~ M. J. Donoghue, J. A. Doyle, and P. o. cantino in P. D. Cantmo et al. (2007): 835 [M. J. Donoghue J. A. Doyle, and P. D. Cantino], converted clade na~e

Registration Number: 250 monosulcate (and globose, columellar) grains that appear to be ancestral in angiosperms Definition: The smallest crown clade con- (Doyle, 2005). Loss of oil cells in the mesophyll taining Ranunculus acris Linnaeus 1753 and dry fruit wall have also been identified as (Ranunculales) and Helianthus annuus Linnaeus apomorphies of Eudicotyledoneae (Doyle and 1753 (Asterales). This is a minimum-crown- Endress, 2000: Fig. 4), but this inference is sen- clade definition. Abbreviated definition: min sitive to outgroup relationships. crown V (Ranunculus acris Linnaeus 1753 & Helianthus annuus Linnaeus). Synonyms: The informal names "eudicots" and "tricolpates" are approximate synonyms (see Etymology: From the Greek eu- (true) and the Comments). name Dicotyledoneae (the name of a more inclu- sive taxon that is now understood to be para- Comments: Until we phylogenetically defined phyletic). Dicotyledoneae is derived from the the nameEudicotyledoneae (Camino et al., 2007), Greek di- (two) and kotyledon (seed leaf). there was no scientific name for this crown clade, which has been referred to informally as either originally Reference Phylogeny: The primary reference "eudicots" or "tricolpates." It was Dahlgren phylogeny is Soltis et al. (2011: Figs. 1, 2). See recognized based on morphology by and Doyle also Doyle and Endress (2000: Fig. 4), Soltis et al. and Bremer (1985) and Donoghue supported in (2000: Figs. 1, 5), Hilu et al. (2003: Fig. 2), Soltis (1989), although only equivocally strongly sup- et al. (2003: Fig. 2), Kim et al. (2004: Fig. 4), Zeng the latter study, and subsequently (cited under Reference et al., (2014: Fig. 3), and Sun et al. (2016: Fig. 2). ported by molecular data Phylogeny). This clade was originally referred (Donoghue and Doyle, Composition: Ranunculales (sensu APG II, to as the "tricolpates" (1991) later coined the 2003) and its presumed sister clade, the latter 1989). Doyle and Hotton ("true dicots") to signify that including Protea/es (Proteaceae, Platanus, and name "eudicots" of "dicots" (dicotyledon- Nelumbo), Sabiaceae, Trochodendraceae (includ- this very large subset paraphyletic group) forms ing Tetracentron), Buxaceae (including Didymeles), ous angiosperms-a that time, the name "eudicots" and Gunneridae (as defined in this volume). a clade. Since has been used most frequently, and it has been phylogenetic studies and Diagnostic Apomorphies: Members of adopted in widely cited APG, 1998; Doyle Eudicotyledoneae are distinguished from other classification schemes (e.g., Hilu et al., 2003; APG II, extant angiosperms by having pollen grains and Endress, 2000; 2005; Soltis and Soltis, that are tricolpate or have aperture conditions 2003; Soltis et al., 2003, IV, 2016), as well that were derived from the tricolpare condition. 2004; APG III, 2009; APG 2002, 2008, Tricolpare pollen appears to have originated as in textbooks (e.g., Judd et al., 2006). on the line leading to crown eudicots from the 2016; Soltis et al., 2005, 2018; Simpson, Eudicotyledoneae

Although cogent arguments have been made APG II (Angiosperm Phylogeny Group). 2003. An in favor of reverting to use of the name tricol- update of the Angiosperm Phylogeny Group pates (Judd and Olmstead, 2004), we chose classification for the orders and families of flowering plants: APG II. Bot. J Linn. Soc. Eudicotyledoneae for the crown clade owing to 141:399-436. rhe widespread use of the name eudicots, which APG III (Angiosperm Phylogeny Group). 2009. An now extends well beyond the plant systematics update of the Angiosperm Phylogeny Group literature. We have defined the name Tricolpatae classification for the orders and families of (this volume and Cancino et al., 2007) for the flowering plants: APG III. Bot. J Linn. Soc. more inclusive clade based on the apomorphy 161:105-121. of tricolpate pollen. Pollen grains are well repre- APG IV (Angiosperm Phylogeny Group). 2016. An sented in the fossil record, and the appearance update of the Angiosperm Phylogeny Group classification for the of tricolpate grains has taken on great impor- orders and families of flowering plants: APG IV. Bot. J Linn. Soc. tance in assessing the timing of angiosperm 181:1-20. evolution (see Soltis et al., 2005). It is not clear Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. that all early fossil tricolpate pollen grains repre- Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis, sent members of Eudicotyledoneae, but they can and M. J. Donoghue. 2007. Towards a phylo- be confidently assigned to Tricolpatae. genetic nomenclature of Tracheophyta. Taxon Camino et al. (2007) defined the name 56:822-846 and El-£44. Eudicotyledoneae using six internal specifiers Dahlgren, R., and K. Bremer. 1985. Major clades of (Ranunculus trichophyllus Villars 1786, Platanus angiosperms. Cladistics 1:349-368. Donoghue, M. occidentalis Linnaeus 1753, Sabia swinhoei W. J., and J. A. Doyle. 1989. Phylogenetic analysis of angiosperms and B. Hemsley 1886, Trochodendron aralioides P. the relationships of Hamamelidae. Pp. 17-45 F. Siebold and Zuccarini 1838, Buxus semper- in Evolution, Systematics, and Fossil History virens Linnaeus 1753, and Helianthus annuus of the Hamamelidae, Vol. 1 (P. Crane and S. Linnaeus 1753). Six specifiers were used because Blackmore, eds.). Clarendon Press, Oxford. at the time measures of support for basal and Doyle, J. A. 2005. Early evolution of angiosperm near-basal eudicot relationships were vari- pollen as inferred from molecular and mor- able, and in some cases low (e.g., see Soltis et phological phylogenetic analyses. Grana al., 2000; Soltis et al., 2003; Hilu et al., 2003; 44:227-251. Doyle, J. A., and K. and Kim et al., 2004). However, more recent P. Endress. 2000. Morphological phylogenetic analysis of basal angiosperms: analyses have provided strong support for the comparison and combination with molecular hypothesis that the members of Ranunculales data. Int. J Plant Sci. 161:Sl21-S153. form a clade that is sister to a clade containing Doyle, J. A., and C. L. Hotton. 1991. Diversification the remaining eudicots (Soltis et al., 2011; Zeng of early angiosperm pollen in a cladistic con- et al., 2014; Sun et al., 2016). Consequently, a text. Pp. 165-195 in Pollen and Spores: Patterns simpler minimum-crown-clade definition with of Diversification (S. Blackmore and S. H. only two specifiers can be used. Barnes, eds.). Clarendon Press, Oxford. Hilu, K. W., T. Borsch, K. Muller, D. E. Soltis, P. S. Soltis, V. Savolainen, M. W. Chase, M. Literature Cited P. Powell, L. A. Alice, R. Evans, H. Sauquet, C. Neinhuis, T. A. B. Slotta, J. G. Rohwer, APG (Angiosperm Phylogeny Group). 1998. An C. S. Campbell, and L. W. Chatrou. 2003. ordinal classification for the families of flower- Angiosperm phylogeny based on matKsequence ing plants. Ann. Mo. Bot. Gard. 85:531-553. information. Am. J Bot. 90:1758-1776.

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