Aquatic Botany 91 (2009) 279–290 Contents lists available at ScienceDirect Aquatic Botany journal homepage: www.elsevier.com/locate/aquabot Systematics of the Alismataceae—A morphological evaluation Samuli Lehtonen * Department of Biology, University of Turku, FI-20014 Turku, Finland A R T I C L E I N F O A B S T R A C T Article history: Received 6 April 2009 Received in revised form 4 August 2009 Accepted 5 August 2009 Available online 13 August 2009 The phylogenetic relationships of aquatic plant families Alismataceae and Limnocharitaceae were investigated by cladistic analysis of morphological and cytological characters. The use of morphological data allowed much wider taxon sampling than in recent molecular studies, and resulted in several new hypotheses. Limnocharitaceae was resolved as a paraphyletic group giving rise to the monophyletic Alismataceae, contradicting with the results from molecular studies. Most of the currently accepted genera were relatively well supported as monophyletic groups, with polyphyletic Caldesia and paraphyletic Limnophyton as notable exceptions. Phylogenetic relationships between different genera remained poorly supported, but it is suggested that the base chromosome number n = 11 is derived from the plesiomorphic n = 7. ß 2009 Elsevier B.V. All rights reserved. Keywords: Alismataceae Limnocharitaceae Morphological data Phylogenetics 1. Introduction The Alismataceae are aquatic or semi-aquatic herbs with a worldwide distribution and are evolutionary closely related to Limnocharitaceae, Butomaceae and Hydrocharitaceae (Soltis et al., 2005). Historically, aquatic plants have presented taxonomic challenges due to convergence, morphological reduction, and phenotypic plasticity which has also been the case for the Alismataceae (Les and Haynes, 1995). The family is treated as having 14 genera (Haynes et al., 1998) and about one hundred species, but species-level classifications are typically conflicting among different authors (Rogers, 1983) and generic circumscriptions are considered unsatisfactory (Cook, 1990; Heywood et al., 2007). Even the limits of the family have remained controversial. It has been suggested by several authors that Limnocharitaceae is nested within Alismataceae (e.g. Pichon, 1946; Les et al., 1997; Chen et al., 2004; Lehtonen and Myllys, 2008), a view not shared by others (e.g. Haynes and Holm-Nielsen, 1992; Petersen et al., 2006). Various classifications below the family level have been proposed as well. Björkqvist (1968) identified three groups of Alismataceae genera based on flower characters. One group was composed of genera with bisexual flowers (Alisma, Baldellia, Caldesia, Damasonium, Echinodorus, Luronium), another contained genera with polygamous flowers (Limnophyton, Lophotocarpus, nowadays included in Sagittaria), and the last group contained genera with unisexual flowers (Burnatia, Wiesneria, Sagittaria). Argue (1976) classified Alismataceae differently, based on his * Tel.: +358 2 333 8743; fax: +358 2 333 5730. E-mail address: samile@utu.fi. 0304-3770/$ – see front matter ß 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.aquabot.2009.08.002 studies of pollen morphology. He recognized three groups: the ‘‘type 1’’ (Caldesia oligococca only), the ‘‘Alisma subtype’’ (including Alisma, Baldellia, Damasonium, Luronium), and the ‘‘Sagittaria subtype’’ (‘typical’ Caldesia, Burnatia, Echinodorus, Sagittaria, Limnophyton, Wiesneria). These pollen types correspond to the base chromosome numbers of the genera: the group with Alisma subtype pollen has a base chromosome number of n = 7 or n = 8, and genera with Sagittaria pollen subtype have a base chromosome number of n = 11 (Argue, 1976) or n = 10 (Mujawar et al., 2003). Molecular phylogenetic studies have greatly improved our understanding on the monocot relationships. It now appears that Butomaceae is either the closest living relative of Alismataceae– Limnocharitaceae clade, and this group is the sister lineage of Hydrocharitaceae (Soltis et al., 2005), or Butomaceae is a sister of Hydrocharitaceae and they together form a sister clade to Alismataceae (Chen et al., 2004). However, molecular studies have been unable to provide a clear picture of evolutionary relationships within the Alismataceae. The common, and perhaps most serious, problem with all the molecular studies dealing with Alismataceae has been their poor taxon sampling. Although the largest three genera comprising most of the family have been almost completely sampled in recent genus-targeted molecular studies (Sagittaria, Keener, 2005; Alisma, Jacobson and Hedrén, 2007; Echinodorus, Lehtonen and Myllys, 2008), none of these studies adequately sampled members of the non-target genera. Hence, these studies were unable to resolve evolutionary relationships at the generic level, except that Echinodorus sensu lato was found to be polyphyletic (Lehtonen and Myllys, 2008). There have been some broad-scale studies investigating monocot systematics which have included various Alismataceae genera, however in these studies, genera are usually represented by just a single S. Lehtonen / Aquatic Botany 91 (2009) 279–290 280 species, and many genera have remained unsampled (Les et al., 1997; Chen et al., 2004; Petersen et al., 2006). It has been well demonstrated that inadequate taxon sampling may produce erroneous phylogenies (e.g. Zwickl and Hillis, 2002). Thus, one possible solution to sampling problem is to utilize morphological characters which have been studied with some extent for all described taxa. However, morphological characters hold various problems for phylogenetic inference, especially in highly plastic aquatic plants. Typically, perhaps most of the morphological characters can be considered to be ‘continuous’, although character states are often named and coded in a way to obscure this fact (Thiele, 1993). This kind of continuously overlapping data are often deemed as inappropriate for phylogenetic inference (Pimentel and Riggins, 1987; Stevens, 1991), although it has also been argued that there are no logical reasons to omit them (e.g. Thiele, 1993; Rae, 1998; Wiens, 2001). Until recently, computer programs required the data to be coded as discrete state, thus possessing a further problem for character state delimitation, but the computer program TNT (Goloboff et al., 2008) allows character states to be continuous ranges instead of separate states (Goloboff et al., 2006). TNT treats continuous characters as additive, and implements Wagner optimization (Farris, 1970) for them. By this way, the transformation from one state to another equals the numerical difference between the states (e.g. if one taxa has 12 stamens and another has 15–24 stamens, the transformation requires 3 steps). If the continuous characters are coded as ranges which overlap between two taxa, no steps are required for the transformation from one state to another (e.g. 15–24 stamens in one taxon vs. 22–28 stamens in another). Hence, if one taxon has very broad variation in certain character, the character is effectively uninformative for the taxa, although it may contain information for other taxa with narrower variation. In this study the Alismataceae–Limnocharitaceae clade was phylogenetically examined on the basis of available morphological and cytological data. Main goals of the study were to test whether the currently accepted families and genera – which are delimited on morphological basis – are actually supported as monophyletic entities by the very same morphological data. Additionally, it is hoped that a preliminary hypothesis of phylogenetic groups draws further attention on investigation of poorly defined groups in more rigorous studies using molecular tools. 2. Materials and methods 2.1. Taxon sampling and classification adopted In order to test the questioned monophyly of the Alismataceae, morphological data was obtained from the most recent taxonomic treatments of varying genera and species from various regions of the world (Table 1). While a priority was to include as many species as possible, several species are poorly defined and for some no adequate character information is available in the literature. Unfortunately, these species had to be excluded. A total of 113 taxa were included in this study. Of these, 104 taxa of Alismataceae and 8 species of Hydrocharitaceae were included in the ingroup while one species, Butomus umbellatus was used as an outgroup. The coding of characters and character states were chosen based on characteristics that prior researchers deemed important within the study group. 2.2. Character sampling and coding Most of the morphological characters available for the present study were continuously variable (Appendix A). Nevertheless, in many cases character states could be delimited on the basis of discontinuities (e.g. round-triangular), and were accordingly coded to have discrete states. Yet, large amount of potentially highly relevant morphological variation (e.g. stamen number) could not be objectively coded due to overlapping variation. Instead of arbitrarily delimiting this variation into discrete character states, the observed variation was coded as ranges from minimum value to the maximum, and analyzed as such. In total 77 characters were coded, 10 as continuous characters (Appendix B) and 67 as having discrete states (Appendix C). Character state coding was based on some herbarium work and field experience, but mostly on critical literature review (Table 1). Continuous overlapping character values were standardized by log10 transformation, because different characters were measured on different scales. All the continuous characters coded as such are treated as additive (Goloboff et al., 2006). Characters were not differentially weighted, but it should be noted that the cost from one state to another equals the numeric difference between the states (Farris, 1990). Multistate characters with a state that could be viewed as a subset of another state were coded as additive Table 1 Reference literature for character coding. Genus References Albidella Alisma Astonia Baldellia Burnatia Butomus Butomopsis Caldesia Pichon (1946), Charlton (2004), Haynes and Holm-Nielsen (1994) Oleson (1941), Björkqvist (1967, 1968), Haggard and Tiffney (1997), Haynes and Hellquist (2000), Jacobson and Hedrén (2007) Aston (1987), Jacobs (1997) Kaul (1976), Vuille (1988), Cook (1990), Haggard and Tiffney (1997), Charlton (2004), Kozlowski et al. (2008) Carter (1960), Symoens and Billiet (1975), Symoens (1984), Haggard and Tiffney (1997) Dahlgren et al. (1985), Charlton (2004). Cook (1990), Haynes and Holm-Nielsen (1992) den Hartog (1957), Carter (1960), Ghafoor (1974), Symoens and Billiet (1975), Kaul (1976), Lai (1977), Symoens (1984), Haggard and Tiffney (1997), Gituru et al. (2002), Liu et al. (2002) Kaul (1976), Vuille (1987), Haggard and Tiffney (1997), Qing-feng et al. (1997), Haynes and Hellquist (2000), Rich and Nicholls-Vuille (2001), Charlton (2004) Heiser and Whitaker (1948), Baldwin and Speese (1955), Kaul (1976), Haynes and Holm-Nielsen (1994), Haggard and Tiffney (1997), Kasselmann and Petersen (1999), Kasselmann (2001), Costa and Forni-Martins (2003), Lehtonen (2006, 2008) Small (1909), Haynes and Holm-Nielsen (1994), Kasselmann and Petersen (1999), Jérémie et al. (2001), Lehtonen and Myllys (2008) Kenton (1982), Dahlgren et al. (1985), Haynes and Holm-Nielsen (1992) Dahlgren et al. (1985), Haynes and Holm-Nielsen (1992) den Hartog (1957), Carter (1960), Ghafoor (1974), Symoens and Billiet (1975), Kaul (1976), Symoens (1984), Aston (1987), Haggard and Tiffney (1997), Jacobs (1997), Kasselmann (2003) Björkqvist (1961), Kaul (1976), Cook (1990), Haggard and Tiffney (1997), Kay et al. (1999) den Hartog (1957), Carter (1960), Symoens and Billiet (1975), Symoens (1984), Cook (1990), Charlton (1991) Oleson (1941), Bogin (1955), Wooten (1973), Kaul (1976), Haynes and Holm-Nielsen (1994), Qing-feng and Jia-kuan (1996), Haggard and Tiffney (1997), Haynes and Hellquist (2000), Costa and Forni-Martins (2003), Keener (2005) Carter (1960), Symoens and Billiet (1975), Symoens (1984), Camenish and Cook (1996), Haggard and Tiffney (1997), Charlton (1999), Mujawar et al. (2003) Damasonium Echinodorus Helanthium Hydrocleys Limnocharis Limnophyton Luronium Ranalisma Sagittaria Wiesneria S. Lehtonen / Aquatic Botany 91 (2009) 279–290 (Wilkinson, 1992), and for the chromosome numbers a specific step-matrix was used. The step-matrix was based on assumption that multiplication of the chromosome content (polyploidy) would require one step (e.g. from n = 7 to n = 14 equals one step), as well as addition or removal of one chromosome (e.g. from n = 7 to n = 8 equals one step). Hence, for example, the change from n = 7 to n = 11 can take place either via addition of extra chromosomes: n = 7 ! n = 8 ! . . . ! n = 11 (in total 4 steps), or via polyploidy and subsequent reduction of chromosomes: n = 7 ! n = 14 ! n = 13 ! . . . ! n = 11 (in total 4 steps). In some taxa chromosome numbers are somewhat variable, for example in Echinodorus and Helanthium base chromosome number appears to be 2n = 22, but in some populations 2n = 33 has been observed (Kasselmann and Petersen, 1999; Costa and Forni-Martins, 2004). As well, Baldellia has been reported to have highly variable chromosome numbers, although majority of the studies report 2n = 16 (Kozlowski et al., 2008). Taxa with variable chromosome numbers were coded according to the most common state (e.g. Baldellia 2n = 16, Echinodorus and Helanthium species with variable numbers as 2n = 22). 2.3. Cladistic analyses The data matrix included 113 terminals, and was therefore too large to be effectively analyzed with simple tree bisection and 281 reconnection (TBR) algorithms (Goloboff, 1999). Therefore, a more aggressive search strategy using parsimony ratchet (Nixon, 1999) was employed. To measure the fit of the data to the obtained phylogeny a jackknife support index (Farris et al., 1996) was calculated. Parsimony analyses were performed with TNT (Goloboff et al., 2008) by completing 10,000 replicates with ratchet (mult = ratchet replic 10,000 hold 10). The character upweighting during ratchet perturbations followed default settings. In the jackknife resampling 100 pseudoreplicates were calculated, each analyzed with 100 ratchet replicates (resample jak replications 100 [mult = ratchet replic 100 hold 1]). 3. Results The analysis resulted in one most parsimonious tree with a length of 451.190 steps, a consistency index of 0.24 and a retention index of 0.81. The tree is presented with jackknife support values and character optimization in Figs. 1–3. Limnocharitaceae is resolved as a paraphyletic grade giving rise to the monophyletic Alismataceae. The monophyly of Alismataceae is supported with 100% jackknife support. Most of the currently accepted genera are supported as monophyletic groups with relatively high jackknife support values. Exceptions are Limnophyton, which includes monospecific genus Astonia, and polyphyletic Caldesia. The Fig. 1. Strict consensus of the two equally parsimonious trees. Non-homoplasious character state changes are marked with black circles, and homoplasious changes with open circles. Character numbers are given above and derived states below the circles. Grey circles indicate changes in continuous characters, the +/ symbols indicating increase/ decrease in the character. Jackknife support values for the clades are shown in larger numbers above the branches. 282 S. Lehtonen / Aquatic Botany 91 (2009) 279–290 Fig. 2. Continued from Fig. 1. phylogenetic relationships between genera remain poorly supported. 4. Discussion Strikingly different hypothesis on Alismataceae phylogeny has been obtained in molecular studies, possibly due to poor taxon and character sampling. It appears likely that the controversies in the molecular phylogenies partly result from the incorrect rooting, possibly due to long-branch attraction to outgroup (Bergsten, 2005). For example, the analysis based on most rapidly evolving sequences (Lehtonen and Myllys, 2008) resulted in deeper level relationships that were highly different from those found in analyses of more conservative sequences, which may indicate that the sequences were giving misleading signal at that phylogenetic level. As well, the two studies utilizing rbcL gene (Les et al., 1997; Chen et al., 2004) resulted in apparently incongruent phylogenies, although the only real difference is in the root position (Fig. 4). Whether or not Limnocharitaceae is nested within Alismataceae has remained controversial in molecular studies, but the monophyly of Limnocharitaceae has not been questioned. In contrast, the current morphology based phylogeny support the monophyletic origin of Alismataceae, but Limnocharitaceae is paraphyletic. Obviously, a well-sampled analysis including molecular data is required to confirm these relationships. 4.1. A review of the Alismataceae classification Not so many hypothesis for the relationships within Alismataceae have been postulated, but it appears that the species with temperate distribution and base chromosome number n = 7(8) and those with tropical distribution and n = 11(10) (hereafter n = 7 and n = 11 species) form two distinct groups. If the rbcL-trees (Les et al., 1997; Chen et al., 2004) are rooted to have monophyletic Alismataceae, these cytological groups appear as sister clades, as they do in the mitochondrial tree (Petersen et al., 2006). In contrast, in the present morphology based phylogeny the monophyletic n = 11 clade is derived from a paraphyletic n = 7 group, although the grouping lacks jackknife support. The currently accepted genera are shortly discussed below. 4.1.1. Damasonium miller A genus with a fragmented distribution pattern following mediterranean climates: one species in California, one species in Australasia, and three species in western-southern Europe (Rich and Nicholls-Vuille, 2001). Damasonium has been considered as an intermediate genus between Alismataceae and Limnocharitaceae due to the presence of multiovulate carpels in most of the species. This character appears to be derived and not plesiomorphic in Damasonium, however. Damasonium californicum is the only species in the genus with a single ovule, and the species appears S. Lehtonen / Aquatic Botany 91 (2009) 279–290 283 Fig. 3. Continued from Fig. 2. to be a sister to rest of the genus. Phylogenetically more recently diverged species have either two, or in the case of D. polyspermum, multiple ovules. Studies based on rbcL sequences placed Damasonium close to Alisma, Baldellia and Luronium (Les et al., 1997; Fig. 4. Phylogenetic relationships within Alismataceae based on recent parsimony analyses of molecular data: (A) Les et al. (1997), based on rbcL. (B) Chen et al. (2004), based on rbcL. (C) Petersen et al. (2006), based on cob, atp1, and rbcL. (D) Lehtonen and Myllys (2008), based on LEAFY, matK, ITS, 5S-NTS, and morphological data. Chen et al., 2004), a grouping that is at least somewhat consistent with the morphological results presented here. 4.1.2. Alisma L A genus of ca. nine species, typically distributed in Northern Hemisphere (Björkqvist, 1967, 1968; Jacobson and Hedrén, 2007). A sister relationship with Damasonium is supported here. The phylogeny of the genus was recently studied with molecular techniques by Jacobson and Hedrén (2007), but remained partially ambiguous. Two species groups within diploid species were found in molecular studies (Jacobson and Hedrén, 2007), of which the A. gramineum-A. wahlenbergii clade is supported here as well. The exact origin of polyploid species has remained obscure, and some species appear to be paraphyletic (Jacobson and Hedrén, 2007). Clearly, the phylogenetic relationships within the genus are still poorly understood. 4.1.3. Baldellia Parl A small genus with two or three species, distributed from Western Europe to northern Africa (Cook, 1990; Kozlowski et al., 2008). Baldellia has been considered as a close relative of Echinodorus (Cook, 1990), but these accounts actually refer to Helanthium (i.e. Echinodorus in a broad, polyphyletic sense). Both of the genera (Baldellia and Helanthium) consist of relatively small plants capable of producing inflorescence stolons, but are unlikely to be closely related. Cytology and molecular studies support the close relationship between Baldellia and Alisma. This hypothesis, however, is not strictly supported by the present analysis: Baldellia and Luronium are resolved as the early diverging lineages of the clade composed of species with base chromosome number n = 11. It should be noted that, even tough the base chromosome number of Baldellia and Luronium appears to be n = 7, chromosomal 284 S. Lehtonen / Aquatic Botany 91 (2009) 279–290 rearrangements have occurred in both genera, since Luronium is reported to have 2n = 42 (Björkqvist, 1961) and Baldellia 2n = 14– 30 (Kozlowski et al., 2008). 4.1.4. Luronium Raf A monospecific genus with a European distribution (Cook, 1990). Luronium is morphologically extremely variable, and the inflorescence can be considered to be partially fertile inflorescence stolon. Molecular studies have suggested affinity with Damasonium, Baldellia and Alisma, but the morphological data suggests closer relationship with the n = 11 species. 4.1.5. Helanthium (Benth. and Hook.f.) Engelm. ex J.G.Sm A genus with Western Hemisphere distribution and highly variable views upon the number of species. Higher species numbers were proposed earlier (four species listed by Fasset, 1955, and nine by Rataj, 1975), but Haynes and Holm-Nielsen (1994) accepted only two species, H. tenellum and H. bolivianum, respectively. Jérémie et al. (2001), while describing a new species, suggested a synonymization of these two. As well, Matias (2007) considered H. tenellum and H. bolivianum as a single species. Although morphologically extremely plastic and taxonomically challenging genus, the limited available DNA evidence indicates the presence of several species (Lehtonen and Myllys, 2008). Bentham and Hooker (1883) described Helanthium as a section under genus Alisma, but later Smith (1905) gave it a generic rank (but misspelled the name as ‘Helianthium’). Since then, most authors have considered Helanthium as a subgenus of Echinodorus (e.g. Fasset, 1955; Rataj, 1975; Rogers, 1983; Haynes and HolmNielsen, 1994), until molecular studies confirmed that they are separate (Soros and Les, 2002; Lehtonen and Myllys, 2008). The close relationship between Helanthium and Ranalisma suggested by Lehtonen and Myllys (2008) is not supported by the present study, but Helanthium is resolved as the first divergent lineage within n = 11 species, and Ranalisma as a sister to Sagittaria. 4.1.6. Caldesia Parl. pro parte A genus with four generally accepted species, but in this analysis C. oligococca was not resolved as a member of the Caldesia-clade. Caldesia are palaeotropical-temperate, but a fossilized Caldesia remains have been reported from the Miocene deposits of North America (Smiley and Rember, 1985; Haggard and Tiffney, 1997). Albidella leaves are morphologically indistinguishable from those of Caldesia, and therefore the leaf remains (Smiley and Rember, 1985) cannot be identified with certainty. However, the fruit fossils from the Early Miocene are typical Caldesia fruits, confirming that Caldesia indeed was present in the New World ca. 20 my ago (Haggard and Tiffney, 1997). The polyphyletic origin of Caldesia suggested here should be tested with molecular data. 4.1.7. Albidella Pichon + Caldesia Parl. pro parte Haggard and Tiffney (1997) noticed the crested fruits of C. oligococca to be highly different from other Caldesia, but their striking similarity with Albidella nymphaeifolia (often treated as Echinodorus) fruits remained unnoticed. Albidella has many other morphological similarities with C. oligococca as well, but apparently only Hutchinson (1959) has ever treated A. nymphaeifolia as a member of Caldesia. However, based on the current tree it would be more appropriate to transfer C. oligococca to Albidella. This question needs to be solved with molecular data. Three varieties are recognized in C. oligococca, on the basis of fruit size and crestation (den Hartog, 1957; Symoens, 1984). Further studies are required to clarify whether these varieties would actually deserve to be raised as full species, or just represent biogeographical variation or ecologically driven plasticity. 4.1.8. Burnatia Micheli A monospecific genus distributed in tropical Africa (Carter, 1960). The genus has never been included in any phylogenetic analysis before, but is here resolved as the sister lineage of the other small and mainly African genus, Wiesneria. These two genera share highly reduced bisexual flowers. 4.1.9. Wiesneria Micheli A small genus of three morphologically highly reduced species from tropical Africa, Madagascar and India (Carter, 1960; Cook, 1990). Camenish and Cook (1996) considered Wiesneria as phylogenetically isolated and old lineage within Alismataceae, but molecular studies have often grouped it together with Sagittaria (Les et al., 1997; Chen et al., 2004). The phylogenetic analysis by Keener (2005) placed Wiesneria closer to Limnophyton than Sagittaria, however, just like the morphological analysis presented here. According to the morphological evidence the closest relative of Wiesneria is Burnatia, a monospecific genus from tropical Africa. Burnatia has never been sampled for any molecular study, but it has reduced flowers as well, although the reduction is not as extreme as in Wiesneria (Carter, 1960; Symoens, 1984). Although a member of the clade with n = 11, Wiesneria appears to be cytologically reduced as well, since n = 10 has been reported for W. trianda (Mujawar et al., 2003). No other chromosome counts for the genus are available. 4.1.10. Limnophyton Miq. + Astonia S.W.L.Jacobs A paleotropical clade with four species (Aston, 1987). Limnophyton australiense, a species described by Aston (1987), was later transferred to a new monospecific genus Astonia by Jacobs (1997). The recognition of a separate genus was based on the differences in bract and stamen coloration, fruit size, the lack of air chambers in Astonia, and the flowering developmental sequence. In Astonia, the peduncle bends toward the water surface after flowering, and the pedicels of fruit producing flowers thicken and elongate until the developing nutlets make contact with the water (Jacobs, 1997). The upper part of the inflorescence, containing only male flowers, grows upwards, thus producing a curved peduncle (Jacobs, 1997). This developmental sequence has not been reported from other species. However, the pedicels of fruit bearing flowers do thicken in Limnophyton obtusifolium as well (Carter, 1960). Based on the present morphological analysis Astonia is clearly nested within well-supported Limnophyton, suggesting that Aston (1987) placed the species correctly. 4.1.11. Echinodorus Rich. ex Engelm A genus of ca. 28 species distributed in Western hemisphere, mostly in the tropics but some species reaching temperate climates (Lehtonen, 2008). As traditionally circumscribed (Fasset, 1955), Echinodorus was a polyphyletic assemblage of New World Alismataceae, but monophyly of the genus was ascertained by removing Albidella and Helanthium as separate genera (Lehtonen and Myllys, 2008). Present analysis supports the monophyly of strictly defined Echinodorus, but does not agree well with the molecular evidence at the species-level resolution, except that E. berteroi is resolved as the sister lineage of the rest of the genus. 4.1.12. Ranalisma Stapf A genus of two species from tropical Africa and South East Asia (Cook, 1990). Ranalisma is here recognized as the sister group of Sagittaria, although the molecular studies have either grouped it close to Helanthium (Lehtonen and Myllys, 2008), or resolved it as a phylogenetically distinct lineage when Helanthium has not been sampled (Les et al., 1997; Chen et al., 2004). The close relationship with Helanthium was also strongly emphasized by den Hartog (1957), although he included Helanthium in Echinodorus. It has also S. Lehtonen / Aquatic Botany 91 (2009) 279–290 285 been anticipated that Ranalisma would be an intermediate genus between Alismataceae and Limnocharitaceae (Charlton and Ahmed, 1973), a suggestion somewhat supported by the rbcL trees (Les et al., 1997; Chen et al., 2004). Morphologically, Ranalisma fruits are basically indistinguishable from those of Sagittaria (Haggard and Tiffney, 1997). highly different views upon the classification (Rogers, 1983). Some species groups recognized here are somewhat comparable with the Keener (2005) Keener’s (2005) molecular phylogeny, but overall the resolution within the genus is quite different. However, neither morphological nor molecular (Keener, 2005) evidence supports the often-recognized subgenera (e.g. Bogin, 1955). 4.1.13. Sagittaria L. Apparently the most species rich genus in Alismataceae, with ca. 40 species (Keener, 2005). The distribution is almost cosmopolitan, but the main species diversity is concentrated in North America (Keener, 2005). Sagittaria species are widely known for their extreme morphological plasticity, which has caused Acknowledgements This study received financial support from the Kone Foundation. I thank Brian Keener and an anonymous referee for contributing to improve this paper. The Willi Hennig Society is acknowledged for making TNT publicly available. Appendix A Continuous characters coded as such Number of parallel veins in blade Number of peudowhorls in inflorescence Bract length Pedicel length Flowers per pseudowhorl Petal length Stamen number Achene length Style length Pollen pore number. Coded after Argue (1976) and Wang et al. (1997) Traditionally coded characters Life form: (0) perennial; (1) annual Rhizome: (0) prolonged and decumbent: (1) short and erect Corms: (0) absent; (1) present Axillary stolons: (0) absent; (1) present Roots: (0) not septate; (1) septate Foliage: (0) submersed only; (1) amphibious; (2) emersed only Leaf base: (0) attenuate-truncate; (1) cordate; (2) sagittate. This character was coded as additive Veins pseudopinnate: (0) no; (1) yes Waxy indument: (0) absent; (1) present Indument: (0) glabrous; (1) pubescent Petiole cross-section: (0) terete; (1) triangular Petioles: (0) solid; (1) hollow Petioles channeled: (0) no; (1) yes Inflorescence: (0) erect; (1) creeping Order of branching: (0) one; (1) two; (2) three. Branching order one refers to inflorescences lacking branches (umbels or racemes), two refers to inflorescences with branches but lacking secondary branches, and three refers to inflorescences with branches which are branched again. This character was coded as additive Flowers and branches: (0) not mixed in pseudowhorls; (1) mixed in pseudowhorls. In some species flowers and branches occur in the same pseudowhorls, but in other species pseudowhorls produce either branches or flowers. This character was coded as inapplicable for the species with branching order one (character 24) Proliferations: (0) absent; (1) present. This character refers to the replacement of flower buds with vegetative buds in inflorescence Inflorescence-stolons: (0) absent; (1) present. In some Alismataceae inflorescences can (especially in submersed conditions) be transformed into vegetative structures with unlimited growth. These modified inflorescences have been called pseudostolons (Charlton, 1968), but are here referred as inflorescence-stolons, following Mühlberg (2000) terminology. Typically inflorescence-stolons lack flowers, but in Luronium one to several flowers are often produced in each pseudowhorl together with normal leaves (Cook, 1990) Rachis: (0) non-alate; (1) alate Bract apex: (0) obtuse; (1) acute-acuminate Bracts per whorl: (0) three; (1) two Bract connection: (0) free; (1) connected at the base; (2) fully connected. This character was coded as additive Pedicel cross-section: (0) cylindric; (1) trigonous Pedicels becoming expanded in fruits: (0) no; (1) yes Pedicel orientation: (0) spreading; (1) reflexed Pedicel length: (0) more or less equally long in all pseudowhorls; (1) shorter in lower pseudowhorls; (2) longer in lower pseudowhorls Sexuality: (0) bisexual flowers only; (1) bisexual and unisexual flowers mixed; (2) unisexual flowers only; (3) dioecious inflorescences. This character was coded as additive Receptacle: (0) flattened; (1) conical Sepal orientation: (0) erect and appressed to the receptacle; (1) spreading to reflexed. In the case of bisexual flowers this character is coded according to the pistillate flowers. Sepal length in relation to petals: (0) shorter than petals; (1) equalling petals; (2) longer than petals Sepal midvein: (0) absent; (1) present Cleistogamous flowers: (0) absent; (1) present Petals: (0) present; (1) often absent in female flowers; (2) often absent in all flowers. This character was coded as additive Petals basally: (0) clawed; (1) not clawed Petals spotted at the base: (0) yes; (1) no Petal colour: (0) creamy-yellow; (1) white; (2) purplish-pink Petals distally: (0) entire; (1) erose; (2) retuse Staminodia: (0) absent; (1) present. This character refers to the presence of non-functional stamens together functional ones in staminate or bisexual flowers 286 S. Lehtonen / Aquatic Botany 91 (2009) 279–290 Appendix A (Continued) Filament pubescence: (0) glabrous; (1) minutely tomentose; (2) pubescent. This character was coded as additive Filament shape: (0) filiform; (1) dilated Anthers: (0) basifixed; (1) versatile Anther shape: (0) oblong-ovate; (1) linear Number of carpels: (0) 3-8; (1) less than 30; (2) 50-150; (3) hundreds. This character was coded as additive Carpel connection: (0) free; (1) somewhat basally connate Carpel arrangement: (0) in whorls; (1) spirally arranged; (2) bunched Carpel opening: (0) open; (1) closed Carpel size: (0) large; (1) small Style position: (0) terminal; (1) ventral Stigma: (0) expanded; (1) punctate Achenes: (0) crowded; (1) loose aggregation Fruit cross-section: (0) laterally flattened; (1) elliptical; (2) round Fruit lateral shape: (0) obovate; (1) ovate; (2) conical; (3) reniformis Fruit longitudinal ribs: (0) absent; (1) dorsally present; (2) dorsally and laterally present. This character was coded as additive Longitudinal ribs: (0) smooth; (1) crested; (2) conspicuous spines Fruit dorsal wings: (0) absent; (1) present Dorsal wings: (0) entire; (1) dentate Fruit lateral wings: (0) absent; (1) present Fruit glands: (0) absent; (1) present Endocarp: (0) thin and membranous; (1) thick and woody Air chambers in fruits: (0) absent; (1) present Ovule number: (0) one; (1) two; (2) numerous. This character was coded as additive Ovule placentation: (0) laminar; (1) basal Testa coat: (0) smooth; (1) sculptured Ornamentation of testa: (0) multicostate; (1) papillose Pollen surface: (0) granulate: (1) spinulate; (2) long-spinulate. This character was coded as additive Pollen shape: (0) polyhedral; (1) spheroidal Chromosome number: (0) 2n = 14; (1) 2n = 16; (2) 2n = 20; (3) 2n = 22; (4) 2n = 26; (5) 2n = 28; (6) 2n = 42. Following transformation costs were applied to chromosome number changes: 0 > 1 1, 0 > 2 3, 0 > 3 4, 0 > 4 2, 0 > 5 1, 0 > 6 2, 1 > 0 1, 1 > 2 2, 1 > 3 3, 1 > 4 3, 1 > 5 2, 1 > 6 3, 2 > 0 3, 2 > 1 2, 2 > 3 1, 2 > 4 3, 2 > 5 4, 2 > 6 3, 3 > 0 4, 3 > 1 3, 3 > 2 1, 3 > 4 2, 3 > 5 3, 3 > 6 2, 4 > 0 2, 4 > 1 3, 4 > 2 3, 4 > 3 2, 4 > 5 1, 4 > 6 4, 5 > 0 1, 5 > 1 2, 5 > 2 4, 5 > 3 3, 5 > 4 1, 5 > 6 3, 6 > 0 2, 6 > 1 3, 6 > 2 3, 6 > 3 2, 6 > 4 4, 6 > 5 3 Appendix B. Data matrix, range coded characters. Butomus umbellatus Limnocharis flava Limnocharis laforestii Hydrocleys nymphoides Hydrocleys mattogrosensis Hydrocleys modesta Hydrocleys martii Hydrocleys parviflora Butomopsis latifolia Helanthium tenellum Helanthium bolivianum Helanthium zombiense Ranalisma humile Ranalisma rostrata Albidella nymphaeifolia Echinodorus berteroi Echinodorus longipetalus Echinodorus horizontalis Echinodorus tunicatus Echinodorus major Echinodorus pubescens Echinodorus palaefolius Echinodorus subalatus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus Echinodorus grisebachii trialatus scaber emersus macrophyllus bracteatus glaucus cylindricus paniculatus reptilis uruguayensis cordifolius floribundus grandiflorus Echinodorus longiscapus Sagittaria montevidensis ssp. montevidensis 0.000 0.000 1.398–1.544 1.699–2.041 1.114–1.699 1.954–2.176 0.778–0.954 1.602–1.699 1.602–1.602? 1.041–1.176 0.000 1.204–1.398 1.602–1.903 0.477–1.079 2.301–2.398 1.602–1.699 2.041–2.204? 0.477–0.845 0.699–0.954 0.000 1.041–1.322 1.176–1.699 0.000–0.845 1.954–2.176 1.000–1.176 1.954–2.079?? 0.699–0.954 0.000 1.301–1.653 1.544–2.243 0.000–0.778 2.362–2.415 1.301–1.398 2.000–2.161 1.544–1.740? 0.699–0.845 0.000 1.477–1.602 1.301–1.699 0.301–0.699 1.954–2.079 0.602–0.778 1.954–1.954 1.000–1.176? 0.477–0.699 0.000 1.477–1.477 1.301–1.544 0.477–0.602 1.903–2.301 0.477–0.778 1.778–1.845 1.000–1.000? 0.699–0.845 0.000 1.301–1.653 1.544–2.243 0.000–0.778 2.362–2.398 1.079–1.255 2.000–2.176 1.544–1.740? 0.699–0.845 0.000 1.041–1.415 1.322–1.813 0.301–1.041 1.699–2.000 0.778–0.845 1.903–2.000 1.041–1.301? 0.477–0.845 0.000 1.114–1.176 1.301–2.146 0.477–1.176 1.778–1.778 0.903–0.954 1.954–2.079 1.301–1.477? 0.000–0.477 0.000–0.301 0.477–0.699 0.699–1.477 0.602–0.778 1.398–1.398 0.954–0.954 0.903–1.176 0.000–0.301 1.079–1.204 0.000–0.477 0.000–0.301 0.477–0.699 1.041–1.792 0.778–1.176 1.699–1.845 0.954–0.954 0.903–1.255 0.903–1.114 1.146–1.255 0.000–0.477 0.301–0.477 0.699–0.845 1.301–1.653 0.699–1.176 1.699–2.079 0.954–0.954 1.176–1.301 0.477–0.477 1.322–1.556 0.477–0.699 0.000 0.477–0.699 0.699–1.000 0.000–0.301 1.778–1.778 0.954–0.954 1.301–1.398 1.000–1.000 1.301–1.301 0.477–0.699 0.000 0.477–0.778 1.000–1.255 0.000–0.477 1.602–1.778 0.954–0.954 1.477–1.602 1.301–1.477 1.176–1.301 0.954–1.114 0.699–0.954 1.301–1.544 1.000–1.176 0.477–0.477 1.477–1.477 0.778–0.778 1.079–1.230 0.000–0.301 1.000–1.176 0.477–1.041 0.000–0.954 0.699–1.544 1.000–1.477 0.477–1.255 1.477–1.845 1.114–1.176 1.176–1.477 0.954–1.255 0.903–1.079 0.699–0.845 0.477–1.041 1.000–1.477 0.477–1.653 0.602–0.903 2.301–2.544 1.602–1.813 1.477–1.602 0.699–0.699 0.954–1.000 0.845–0.954 0.301–0.699 1.000–1.398 1.000–1.477 0.301–0.699 2.000–2.000 1.279–1.380 1.255–1.447 0.477–0.699? 0.845–1.114 0.000–0.778 1.477–1.778 1.301–1.602 0.845–1.699 2.000–2.000 1.279–1.380 1.415–1.633 0.602–1.000? 0.477–0.699 0.778–0.845 1.176–1.301 1.000–1.000 0.845–0.954 1.778–1.845 1.079–1.079 1.301–1.301 0.301–0.301 1.114–1.204 0.699–0.954 0.778–1.255 1.176–1.301 0.699–1.000 0.954–1.176 2.079–2.176 1.079–1.079 1.398–1.544 1.000–1.000? 0.845–1.041 0.903–1.255 1.176–1.544 0.000–1.176 0.845–1.398 2.079–2.079 1.079–1.079 1.255–1.398 0.602–1.000? 0.699–0.954 0.699–1.176 1.176–1.778 0.301–1.176 0.477–1.255 1.845–2.000 1.079–1.079 1.176–1.362 0.699–1.176 1.079– 1.204 0.477–0.845 0.477–1.079 0.477–1.398 0.301–1.000 0.477–0.954 1.699–1.699 0.954–1.079 1.176–1.342 0.301–0.699 0.954–1.041 0.477–0.845 0.602–1.176 1.000–1.398 0.301–0.845 0.477–0.845 1.903–1.903 1.079–1.079 1.176–1.301 0.699–0.699? 0.699–0.954 0.699–1.322 1.000–1.301 0.699–1.398 0.477–0.778 1.602–1.602 1.114–1.255 1.362–1.519 0.778–1.000? 0.954–1.114 0.903–1.322 0.778–1.000 0.699–1.000 0.477–1.079 2.146–2.204 1.146–1.342 1.301–1.477 0.477–1.000? 0.845–1.041 0.778–0.954 1.000–1.301 1.176–1.398 0.699–1.114 1.903–1.903 1.301–1.380 1.398–1.398 1.000–1.000 1.114–1.322 0.954–1.041 0.903–1.322 1.176–1.813 0.301–1.000 0.699–1.398 2.176–2.301 1.176–1.255 1.204–1.431 0.301–0.699? 0.845–1.114 0.778–1.146 0.778–1.255 1.000–1.255 0.778–1.230 2.342–2.398 1.380–1.477 1.342–1.477 0.699–0.699? 0.699–0.845 0.602–1.114 0.954–1.279 0.903–1.000 0.778–0.954 2.342–2.398 1.380–1.477 1.477–1.477 0.845–0.845? 0.699–0.845 0.602–1.041 1.000–1.740 1.000–1.602 0.699–1.322 2.301–2.398 1.279–1.342 1.176–1.477 0.000–0.903 1.041–1.204 0.477–0.477 0.000–0.477 0.903–0.903 1.544–1.778 0.477–0.699 2.079–2.176 1.176–1.342 1.176–1.176 0.477–0.477? 0.477–0.699 0.477–0.778 0.845–1.778 1.176–1.699 0.602–1.000 2.176–2.301 1.255–1.342 1.301–1.301 0.301–0.845? 0.699–0.954 0.477–0.903 1.000–1.699 1.477–1.875 0.778–1.342 2.079–2.176 1.176–1.447 1.114–1.477 0.301–1.000 1.079–1.176 1.041–1.322 0.903–1.204 1.000–1.602 1.000–1.602 0.845–1.255 2.255–2.342 1.380–1.477 1.255–1.447 0.301–0.477 1.079–1.176 0.845–1.114 0.699–1.114 1.176–1.653 1.176–1.813 0.845–1.279 2.301–2.342 1.322–1.544 1.301–1.477 0.301–0.699 1.146– 1.279 0.699–1.041 0.602–1.000 0.845–1.447 0.699–1.544 0.699–1.176 2.301–2.342 1.279–1.447 1.255–1.398 0.000–0.699 1.079–1.204 0.845–1.301 0.000–1.176 0.699–1.491 0.699–1.531 0.000–0.477 2.176–2.398 1.301–1.477 1.301–1.477 0.602–0.903 1.041–1.114 S. Lehtonen / Aquatic Botany 91 (2009) 279–290 287 Appendix B (Continued) Sagittaria montevidensis ssp. chilensis Sagittaria intermedia Sagittaria calycina ssp. calycina Sagittaria calycina ssp. spongiosa Sagittaria sprucei Sagittaria rhombifolia Sagittaria planitiana Sagittaria guayanensis ssp. guayanensis Sagittaria guayanensis ssp. lappula Sagittaria tengtsungensis Sagittaria pygmaea Sagittaria potamogetifolia Sagittaria trifolia Sagittaria sagittifolia Sagittaria natans Sagittaria cuneata Sagittaria longiloba Sagittaria engelmanniana Sagittaria australis Sagittaria brevirostra Sagittaria latifolia Sagittaria secundifolia Sagittaria fasciculata Sagittaria weatherbiana Sagittaria graminea Sagittaria chapmanii Sagittaria isoetiformis Sagittaria lancifolia ssp. lancifolia Sagittaria lancifolia ssp. media Sagittaria ambigua Sagittaria papillosa Sagittaria cristata Sagittaria macrocarpa Sagittaria teres Sagittaria rigida Sagittaria sanfordii Sagittaria macrophylla Sagittaria demersa Sagittaria platyphylla Sagittaria subulata Sagittaria filiformis Sagittaria kurziana Luronium natans Burnatia enneandra Baldellia ranunculoides Baldellia repens Baldellia alpestris Caldesia parnassifolia Caldesia reniformis Caldesia oligococca var. oligococca Caldesia oligococca var. echinata Caldesia oligococca var. acanthocarpa Caldesia grandis Astonia australiensis Limnophyton obtusifolium Limnophyton angolense Limnophyton fluitans Wiesneria trianda Wiesneria filifolia Wiesneria schweinfurthii Damasonium californicum Damasonium alisma Damasonium polyspermum Damasonium minus Damasonium bourgaei Alisma plantago–aquatica Alisma triviale Alisma lanceolatum Alisma subcordatum 0.845–1.301 0.000–1.176 0.699–1.491 0.699–1.531 0.000–0.477 2.176–2.398 1.301–1.477 1.301–1.477 0.602–0.903 1.041–1.114 0.477–0.699 0.477–0.903 0.301–0.301 1.398–1.623 0.301–0.477 2.000–2.398 1.079–1.322 1.176–1.342 0.301–0.301? 0.845–1.301 0.477–1.079 0.477–1.301 0.699–1.398 0.000–0.477? 1.301–1.477 1.255–1.398 0.699–0.699? 0.845–1.301 0.301–0.602 0.301–0.699 0.699–1.301 0.000–0.477? 1.301–1.477 1.255–1.398 0.699–0.699? 1.041–1.041 0.477–1.079 0.602–0.778 0.000–1.176 0.301–0.477 1.699–1.903 0.954–1.079 1.602–1.778 0.699–0.699? 0.954–1.114 0.301–1.000 0.778–1.477 1.342–1.690 0.000–0.477 2.176–2.477 0.954–1.079 1.505–1.845 0.845–1.079? 0.954–1.079 0.301–0.477 0.699–1.079 0.699–1.176 0.000–0.477 1.699–2.079 0.778–0.778 1.176–1.342 0.000–0.301? 1.041–1.114 0.301–0.845 0.954–1.176 0.845–1.255 0.000–0.477 1.903–2.000 0.778–0.954 1.230–1.342 0.301–0.699 1.114–1.204 1.041–1.114 0.301–0.845 0.954–1.176 0.845–1.255 0.000–0.477 1.903–2.000 0.778–1.000 1.477–1.602 0.699–0.954 1.114–1.204 0.000–0.477 0.477–0.845 0.477–0.699 1.301–1.778 0.301–0.477 2.000–2.000 1.176–1.380 1.477–1.602 1.000–1.000 1.079–1.079 0.000 0.301–0.477 0.477–0.699 1.176–1.602 0.301–0.602 1.845–1.954 0.954–1.176 1.176–1.301 1.000–1.079 1.079–1.146 0.000–0.477 0.301–0.699 0.301–0.699 1.079–1.602 0.301–0.477 1.602–2.000 0.954–1.322 1.398–1.477 1.000–1.000? 0.477–1.041 0.699–1.146 0.602–1.255 1.000–1.255 0.301–0.477? 1.301–1.380 1.477–1.602 1.000? 0.477–1.041 0.301–1.000 0.477–1.176 0.699–1.176 0.301–0.477 2.000–2.176 1.301–1.380 1.398–1.653 0.301–0.903 1.041–1.301 0.000–0.477 0.301–0.778 0.477–1.176 1.000–1.301 0.477–0.477 1.903–2.000 1.301–1.380 1.477–1.602 0.301–0.903? 0.699–1.176 0.301–1.000 0.845–1.602 0.699–1.301 0.301–0.477 1.903–2.079 1.176–1.380 1.255–1.415 0.000–0.602 1.041–1.176 0.778–0.778 0.699–1.230 0.778–1.176 1.301–1.398 0.301–0.477 1.778–2.176 1.079–1.204 1.079–1.398 0.000–0.778? ? 0.301–0.602 0.699–1.398 1.176–1.544 0.301–0.477 1.903–2.079 1.176–1.398 1.380–1.602 1.000–1.322? ? 0.699–1.079 0.845–1.477 0.477–1.362 0.301–0.477 1.903–2.079 1.176–1.398 1.322–1.505 0.602–1.230? ? 0.699–1.079 1.000–1.602 1.000–1.398 0.301–0.477 1.903–2.079 1.176–1.398 1.322–1.491 0.602–1.230? 0.845–1.114 0.477–0.954 0.477–0.903 0.903–1.398 0.301–0.477 1.954–2.255 1.204–1.255 1.398–1.544 1.000–1.301 1.000–1.146 0.000 0.301–0.699 0.000–0.301 0.778–1.398 0.301–0.477 1.903–2.079? 1.398–1.477 0.699–0.699? 0.000 0.301–0.699 0.301–0.699 1.176–1.653 0.301–0.477 1.477–1.699? 1.398–1.477 0.699–0.699? 0.000–0.477 0.301–0.903 0.477–1.079 1.845 0.301–0.477? 1.079–1.255 1.255–1.342 0.477–0.477? 0.000–0.477 0.301–0.903 0.301–1.176 0.699–1.204 0.301–0.477 1.778–1.903 1.079–1.255 1.176–1.447 0.301–0.301 1.041–1.342 0.000–0.477 0.477–1.079 0.301–1.176 1.301 0.301–0.477? 1.255–1.380 1.079–1.322 0.000? 0.000 0.301–0.602 0.301–0.477 1.000–1.544 0.301–0.477 1.778–1.903 1.079–1.176 1.342–1.447 0.301–0.301? 0.845–0.954 0.602–1.114 0.477–0.778 1.279–1.398 0.301–0.477 1.903–2.176 1.301–1.447 1.204–1.398 0.477–0.845 1.000–1.230 0.845–0.954 0.602–1.114 0.477–0.778 1.279–1.398 0.301–0.477 1.903–2.176 1.301–1.447 1.204–1.398 0.477–0.845 1.000–1.230 0.000 0.477–1.079 1.000–1.477 1.176–1.544 0.301–0.477 1.778–1.903 1.176–1.322 1.398–1.477 0.301–0.301? 0.000 0.602–1.079 0.602–0.903 1.000–1.653 0.301–0.477 1.903–2.079 1.176–1.322 1.079–1.176 0.000–0.477 1.079–1.176 0.000 0.477–0.778 0.602–1.000 1.176–1.477 0.301–0.477 1.778–1.903 1.079–1.255 1.398–1.477 0.602–0.845 1.041–1.204 0.000–0.477 0.477–0.699 0.301–0.477 1.398 0.301–0.477? 1.079–1.255 1.301–1.477 0.699–0.699? 0.000 0.301–0.602 0.301–0.477 1.000–1.477 0.301–0.477 1.778–1.903 1.079–1.176 1.301–1.477 0.477–0.602? 0.000–0.954 0.301–0.903 0.477–0.778 1.000–1.477 0.301–0.477 1.778–1.903 1.176–1.380 1.301–1.477 0.903–1.146 1.000–1.342 0.477–0.954 0.477–1.000 0.699–0.903 0.699–1.398 0.301–0.477 1.778–1.903 1.176–1.380 1.301–1.477 0.301–0.778? 0.477–0.602 0.477–0.699 0.845–1.041 0.778–1.505 0.477–0.477 2.176–2.176 1.079–1.204 1.491–1.544 0.778–1.079 1.114–1.204 0.954–1.041 0.301–0.845 0.301–0.602 1.000–1.301 0.477–0.477 1.903–2.079 1.079–1.176 1.176–1.176 1.041–1.041? 0.000–0.845 0.477–0.903 0.477–0.778 0.699–1.301 0.301–0.477 1.903–1.954 1.176–1.322 1.079–1.301 0.477–0.778? 0.699–0.954 0.301–0.602 1.176–1.602 0.301–1.398 0.000–0.477 1.301–1.778 0.778–0.778 1.301–1.301 0.301–0.602 1.114–1.279 0.000 0.301–1.000 0.477–1.000 1.176–1.653 0.301–0.477 1.778–1.903 0.954–1.079 1.699–1.699 0.000–0.477? 0.000 0.699–1.301 0.477–1.398 1.176–1.653 0.301–0.477 1.778–1.903 0.954–1.176 1.699–1.699 0.301–0.903? 0.000–0.477?? 1.477–1.845 0.000–0.699 1.602–2.000 0.778–0.778 1.000–1.301 0.000 1.279–1.362 0.699–0.845 0.000–0.699 1.000–1.398 0.477–1.000 0.477–0.477 1.000–1.477 0.954–0.954 1.176–1.398 0.000 1.301–1.322 0.000–0.477 0.000–0.301 0.699–0.699 1.301–1.778 0.778–1.176 1.602–1.903 0.778–0.778 1.301–1.544? 1.342–1.398 0.000–0.477 0.301–0.477? 1.301–1.778 0.000–0.778 1.699–2.079 0.778–0.778 1.255–1.301?? 0.000–0.477 0.000??? 1.477–1.602 0.778–0.778??? 0.699–1.041 0.477–0.778 1.000–1.000 1.176–1.602 0.477–0.477 1.544–1.653 0.778–0.778 1.477–1.602 1.000–1.176 1.000–1.079 1.114–1.230 0.602–0.903 1.000–1.000 1.000–1.602 0.477–0.477 1.602–1.699 0.778–0.778 1.477–1.477 1.000–1.176? 0.954–1.230 0.699–1.079 1.176–1.778 1.000–1.544 0.477–0.477 1.477–1.778 0.778–0.778 1.477–1.778 0.000 0.301–0.301 0.954–1.230 0.699–1.079 1.699–2.061 1.000–1.544 0.477–0.477 1.398–1.398 0.778–0.778 1.176–1.477 0.000? 0.954–1.230 0.699–1.079 1.398–1.544 1.000–1.544 0.477–0.477 1.602–1.778 0.778–0.778 1.699–1.903 0.000? 0.954–1.041 0.477–0.778 1.301–1.301 1.301–1.398 0.477–0.477 1.778–1.903 0.954–1.079 1.176–1.176 1.176–1.176 1.255– 1.255 1.041–1.301 0.477–0.903 1.477–1.477 0.954–1.146 1.000–1.362 1.778–1.799 0.778–0.778 2.000–2.114 0.778–0.778? 1.230–1.279 0.699–0.845 1.000–1.301 1.301–1.653 0.477–1.000 1.778–1.954 0.778–0.778 1.602–1.699? 1.146–1.255 1.230–1.398 0.602–0.778 1.301–1.477 0.954–1.146 0.778–1.176 1.778–1.954 0.778–0.778 1.903–1.903 0.699–0.699 1.255– 1.255 0.477–0.477 0.301–0.602 1.000–1.301 1.000–1.000 0.477–1.079 1.845–1.845 0.778–0.778 1.602–1.699 1.000–1.000? 0.000–0.477 0.699–0.903 0.301–0.477 0.000 0.477–0.903 1.176 0.477–0.477 1.477–1.602 0.699–1.000 1.301–1.342 0.000 0.699–1.000 0.301–0.477 0.000–0.301 0.477–0.903 1.176 0.477–0.477 1.301–1.477 1.000–1.176? 0.000–0.477 0.699–1.079 0.301–0.477 0.000–0.301 0.477–0.903 1.176 0.477–0.477 1.477–1.602 1.301–1.301 1.255–1.255 0.477–0.699 0.000–0.954 1.000–1.176 1.301–1.778 0.602–1.000 1.778–2.000 0.778–0.778 1.477–1.740 1.477–1.778 1.255–1.301 0.477–0.699 0.000–0.602 0.699–0.699 1.176–1.477 0.699–1.114 1.580–1.672 0.778–0.778 1.477–1.778 1.301–1.699 1.279– 1.322 0.477–0.699 0.000–0.301? 1.176–1.477 0.602–0.903 1.699–1.763 0.778–0.778?? 1.477–1.477 0.477–0.699 0.301–0.602? 1.176–1.477 0.602–0.903 1.301–1.477 0.778–0.778 1.699–1.778? 1.398–1.519 0.477–0.699 0.000–0.699? 1.176–1.477 0.602–1.000 1.491–1.591 0.778–0.778?? 1.255–1.301 0.699–0.954 0.602–0.954 1.146–1.477 1.000–1.556 0.602–1.000 1.531–1.806 0.778–0.778 1.230–1.491 0.778–1.176 1.255–1.342 0.699–0.954 0.602–0.954 1.602–1.954 1.079–1.556? 1.580–1.653 0.778–0.778 1.255–1.477 0.602–0.778 1.398–1.505 0.699–0.845 0.477–0.778 0.845–1.230 1.079–1.505 0.477–0.778 1.643–1.813 0.778–0.778 1.301–1.462 0.602–0.778 1.255–1.505 0.699–0.845 0.477–1.000 0.778–1.176 0.845–1.301? 1.255–1.398 0.778–0.778 1.176–1.398 0.301–0.602 1.322–1.415 288 S. Lehtonen / Aquatic Botany 91 (2009) 279–290 Appendix B (Continued) Alisma gramineum Alisma wahlenbergii Alisma orientale Alisma canaliculatum Alisma rariflorum 0.000–0.699 0.477–0.699 0.699–1.114 1.000–1.477 0.477–0.954 1.342–1.568 0.778–0.778 1.255–1.415 0.602–0.699 1.301–1.398 0.000–0.477 0.000–0.301 0.301–0.699 0.778–1.342 0.477–0.778 1.204–1.462 0.778–0.778 1.204–1.380 0.477–0.602? 0.699–0.954 0.602–0.954 1.146–1.342 0.903–1.342 0.477–0.954 1.398–1.519 0.778–0.778 1.114–1.322 0.602–0.699 1.279– 1.322 0.477–0.699 0.477–0.778 0.845–1.176 0.778–1.380 0.477–0.954 1.398–1.591 0.778–0.778 1.301–1.477 0.699–0.903 1.380–1.462 0.477–0.699 0.477–0.778 0.845–1.000 1.342–1.544 0.301–0.477 1.699–1.845 0.778–0.778 1.301–1.519 1.041–1.176 1.255– 1.342 Appendix C. Data matrix, traditionally coded characters? = missing data, = inapplicable data. Polymorphic characters are scored as follows: a = [01], b = [12] Butomus umbellatus Limnocharis flava Limnocharis laforestii Hydrocleys nymphoides Hydrocleys mattogrosensis Hydrocleys modesta Hydrocleys martii Hydrocleys parviflora Butomopsis latifolia Helanthium tenellum Helanthium bolivianum Helanthium zombiense Ranalisma humile Ranalisma rostrata Albidella nymphaeifolia Echinodorus berteroi Echinodorus longipetalus Echinodorus horizontalis Echinodorus tunicatus Echinodorus major Echinodorus pubescens Echinodorus palaefolius Echinodorus subalatus Echinodorus grisebachii Echinodorus trialatus Echinodorus scaber Echinodorus emersus Echinodorus macrophyllus Echinodorus bracteatus Echinodorus glaucus Echinodorus cylindricus Echinodorus paniculatus Echinodorus reptilis Echinodorus uruguayensis Echinodorus cordifolius Echinodorus floribundus Echinodorus grandiflorus Echinodorus longiscapus Sagittaria montevidensis ssp. montevidensis Sagittaria montevidensis ssp. chilensis Sagittaria intermedia Sagittaria calycina ssp. calycina Sagittaria calycina ssp. spongiosa Sagittaria sprucei Sagittaria rhombifolia Sagittaria planitiana Sagittaria guayanensis ssp. guayanensis Sagittaria guayanensis ssp. lappula Sagittaria tengtsungensis Sagittaria pygmaea Sagittaria potamogetifolia Sagittaria trifolia Sagittaria sagittifolia Sagittaria natans Sagittaria cuneata Sagittaria longiloba Sagittaria engelmanniana Sagittaria australis Sagittaria brevirostra Sagittaria latifolia Sagittaria secundifolia Sagittaria fasciculata Sagittaria weatherbiana Sagittaria graminea Sagittaria chapmanii 10000100001000000001000000000100000200010101000001200–0–0000200–?? 11000100001001001001001110000000000001010011000010010–0–000020101? 11000100001001001001001110000000000001010011000010010–0–00002010?? 10000110000101001000000000000000000a01010101000000210–0–000020111? 10000110000101001000000000000200001001010101000000210–0–00002011?? 10000100000101001001000000000000001000010101000000210–0–00002011?? 10000110000101001000000000000010001001010101000000210–0–00002011?? 1100010000010100000100000000021000100a010101000000210–0–00002011?? 0100010000100a000001000000000100011100000101000000210–0–000020111? 1100010000000a00110101000000000000112000001021111111200–0000010–11 1100010000000a00110101000000000000112000001021111111200–0000010–11 1100010000000a00110101000000000000112000001021111111200–0000010–11 1100010000100a001101110000011000001b00000010111010000–100100010–11 110001a000010a001101110000011000001100000010111010000–100100010–11 110001100000002000010000000010000??10000001021111103210–0000010–11 010001a000100021000100000001100000110000102011101020200–0100010–11 1000020100100000100100001001000001110000113011101000200–0000010–11 1000021000000100100100001001000001110000103011101020200–0100010–?? 1000021000000000100100001001000001110000103011101020200–0100010–?? 1000010100100000100100000001100001010000112011101020200–0100010–11 1000020001000011000100000001100001010000112011101020200–0100010–?? 100001a001101011101100000001100001010000112011101020200–0100010–?? 1000010001101011101100000001100001010000112011101020200–0100010–11 1000010100100a11100100001001100001110000112011101020200–0100010–11 1000010100100000101100001001100001110000112011101020200–0000010–?? 1000021001000011100100000001100001110000112011101020200–0100010–?? 1000021001000011100100000001100001110000112011101020200–0000010–?? 1000021001000011100100000001100001110000112011101020200–0000010–11 1000021001000011101100001001100001110000112011101020200–0100010–?? 1000021010000000000100000001100001110000112011101020200–0100010–?? 1000020010000000000100000001100001110000112011101020200–0100010–?? 1000010000100011100100000001100001110000112011101020200–0000010–11 1000020000000100100100000001100001110000112011101020200–0100010–?? 1000010100000a00100100000001100001110000112011101020200–0100010–?? 100002a001000111100100000001100001110000112011101020200–0100010–11 1000021001000011100100000001100001110000112011101020200–0100010–11 100002a001000011100100000001100001110000112011101020200–0100010–11 100002a001000011100100000001100001110000112011101020200–0100010–11 1000112000000a110001010110110000000100000030111010000–100a00010–21 1000112000000a0–0001010110110000000100100030111010000–100a00010–?? 10001220001000110001010110110000001100110030111010000–100a00010–?? aa00112000?00a0–0001010110110000001100100030111010000–100a00010–?? 0100112000?00a0–0001010110110000001100000030111010000–100a00010–?? 10001220001000110001010111110000001100000030111010000–100a00010–?? 100011000010000–0001010111110000000100000030111010000–100000010–?? 110012000a10000–0001000111110000001100000030111010000–100000010–?? 111011200a10010–0001010110110000000100000030111010000–110000010–21 111011200a10010–0001010110110000000100000030111010000–110000010–?? 111011000000000–0001010101210000001100010030111010000–100100010–21 1110110000?0000–0001000–01210000001100010030111010000–110000010–21 1111112000?0000–0001010101210000001100010030111010000–100a00010–?? 1111122000?000110001010000211000001100000030111010000–100100010–?? 11111120001000110001010001111000000100000130111010000–100a00010–21 1000102000000a0–0001010001111000001100000030111010000–100a00010–?? 11111120001000110001010000211000001100000030111010000–100100010–21 10111220000000110001010000211000001100000130111010000–100a00010–?? 11111120001000110001010000211000001100000030111010000–101100010–?? 111112200010000–0001010001211000001100000030111010000–101000010–?? 11111220000000110001010000211000001100000030111010000–101000010–?? 111111200a1000110001010000211000001100000030111010000–100a00010–21 100010000000000–0001010000211000001100110030111010000–111100010–?? 100111000000000–0001010000211000001100110030111010000–101a00010–?? 1111110000?000110001010002211000001100210030111010000–101100010–?? 1aa011000010000–0001010002211000001100210030111010000–101100010–21 1001110000?000100001010000211000001100210030111010000–101100010–?? S. Lehtonen / Aquatic Botany 91 (2009) 279–290 289 Appendix C (Continued) Sagittaria isoetiformis Sagittaria lancifolia ssp. lancifolia Sagittaria lancifolia ssp. media Sagittaria ambigua Sagittaria papillosa Sagittaria cristata Sagittaria macrocarpa Sagittaria teres Sagittaria rigida Sagittaria sanfordii Sagittaria macrophylla Sagittaria demersa Sagittaria platyphylla Sagittaria subulata Sagittaria filiformis Sagittaria kurziana Luronium natans Burnatia enneandra Baldellia ranunculoides Baldellia repens Baldellia alpestris Caldesia parnassifolia Caldesia reniformis Caldesia oligococca var. oligococca Caldesia oligococca var. echinata Caldesia oligococca var. acanthocarpa Caldesia grandis Astonia australiensis Limnophyton obtusifolium Limnophyton angolense Limnophyton fluitans Wiesneria trianda Wiesneria filifolia Wiesneria schweinfurthii Damasonium californicum Damasonium alisma Damasonium polyspermum Damasonium minus Damasonium bourgaei Alisma plantago–aquatica Alisma triviale Alisma lanceolatum Alisma subcordatum Alisma gramineum Alisma wahlenbergii Alisma orientale Alisma canaliculatum Alisma rariflorum 111111000000000–0001010000211000001100110030111010000–101100010–?? 10001200001000110001010000211000001100200030111010000–100100010–21 10001200001000110001010000211000001100200030111010000–100100010–?? 11111200001000110001000000211000001100000030111010000–101a00010–?? 10001200001000110001010000211000001100000030111010000–101a00010–21 a11110000010000–0001010000211000001100210030111010000–101100010–21 a111100000?0000–0001010000211000001100210030111010000–101100010–?? 111110000000000–0001010000211000001100210030111010000–0–1100010–?? 111111200010000–0001010111211000001100210030111010000–100a00010–21 111111000010000–0001010112211000001100210030111010000–0–0000010–?? 111112200010000–0001010112211000001100000030111010000–100a00010–21 111110000000000–0001010112211000001100010030111010000–0–0000010–?? 111111a00010000–0001010112211000001100210030111010000–0–1000010–?? 111110000000000–0001010111211000001100010030111010000–101a00010–21 11111120000001100001010002210000001100010030111010000–101100010–?? 11111000000001100001010112211000001100010030111010000–0–1100010–?? 110001a000000111110100000000?001010110000010011001212–0–0000010–01 1100010000000010000100000030120011110001001021111100201001?0010–11 1100010000000a00100100000000100100011000001021101101100–0000010–00 1100010000000100110100000000100000021000001021101101100–0000010–0? 1100010000000a001101000000001001000a1001011021101101100–0000010–?? 1100011000000011100100000000000000110000001021101120200–001a010–01 1100011000000011100100000000010000110000001021101120200–001a010–?? 1100011000000020000101000000100000110001101021111113210–0000010–00 1100011000000020000101000000100000110001101021111113210–0000010–?? 1100011000000020000101000000100000110001101021111113220–0000010–?? 1100011000000010100100000000000000110000001021101120200–0010010–01 1100012000000000000100011210100000100011001021110110120–0010010–?? 1100012001100011000100011010100000110001001021110120100–0011010–11 1100012001000011000100001010100000110001001021110120100–0011010–11 1000010101000011000100000010100000110001001021110120100–0011010–?? 01000100000001001001020–020120021100001000001101121200–0011010–21 11000100000001001001020–2201200211?0001000001101121000–0011010–?? 01000100000001001001020–0201200201b0001000001101121200–0011010–21 11000200000000110001000000001000000b1001111101101002200–0000010–00 1100020000000011000100000000100000011000001101101002200–0000110–00 01000200000000000001000000001000000b1000001101101002200–0000200–01 010002a0000000110001000000001000001b1000001101101002200–0000110–00 01000200000000110001000000001000000b1000001101101002200–0000110–00 11000100000000210001000000000000000b1001001000110001100–0000010–00 1100020000000021000100000000000000111001001000110001100–0000010–00 11000200000000210001000000000000000210010010001100001–0–0000010–00 110002a0000000210001000000000000000110010010001100001–0–0000010–00 11000100000000110001000000000001001210010010001100001–0–0000010–00 11000100000000110001000000000001000200010010001100001–0–0000010–?? 110002a0000000210001000000000000000210010010001100001–0–0000010–00 11000200000000210001000000000000000100010010001100001–0–0000010–00 11000200000000110001000000000000000110010010001100001–0–0000010–00 References Argue, C.L., 1976. 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