By Scott A. Mori, Chih-Hua Tsou, Arne Anderberg, Ya-Yi Huang & Ghillean T. Prance<\/p>\n
Click on phylogeny of Lecythidaceae<\/a> to retrieve papers related to this subject. A summary of these papers is provided below. All references cited in the essay can be retrieved from the Literature Module.<\/p>\n The use of anatomical, morphological, and molecular data in a phylogenetic context has added a great deal to the understanding of evolutionary relationships within Lecythidaceae and its nearest relatives. Sometimes molecular data has unequivocally supported what we suspected was true; for example, that the central AmazonianAsteranthos brasiliensis<\/i> did not belong to the Lecythidaceae where it had previously been assigned as the only member of the African subfamily Napoleonaeaceae in the New World (Prance & Mori, 1979). Tsou (1994) was the first to suggest that the closest relatives of A. brasiliensis<\/i> were the African Syctopetalaceae based on embryology and this was confirmed by Appel (1996) based on morphology, especially the presence of ruminate endosperm in both taxa, as evidence. Molecular data (Morton et al., 1997) also supported these conclusions and A. brasiliensis<\/i> is now considered as belonging to the Syctopetalaceae (Appel, 1996: Mori et al., 2007). Another example is molecular support for the long-standing hypothesis that actinomorphic flowers preceeded zygomorphic flowers and that Grias<\/i> and Gustavia<\/i> are the most basal Neotropical Lecythiaceae (Mori et al., 2007). An additional example is the confirmation that Lecythis<\/i> is not monophyletic as shown in a recently published two gene tree (Mori et al., 2007). This was not unexpected because Mori (in Mori & Prance, 1990) recognized the extreme androecial variation found in Lecythis<\/i> as representing separate sections of the genus. The new analysis suggests, however, that the current circumscription of Lecythis<\/i> is not monophyletic and Mori\u2019s sections should be considered genera.<\/p>\n Finally, our most recent molecular study of Lecythidaceae (Mori et al., 2007) summarizes what is currently known about the classification of the family and this supports previous classifications not based on molecular data. Our study shows that the Napoleonaeaceae, Scytopetalaceae, and Lecythidaceae conform to highly supported clades. Separation of the Lecythidaceae into subfamilies Foetidioideae, Planchonioideae, and Lecythidoideae is consistent with strongly supported clades hypothesized by Mori et al. (2007). Moreover, molecular data demonstrate that the New World Lecythidoideae are sister to the Old World Foetidia<\/i>\u2013Petersianthus<\/i> clade, and morphological features suggest that the link is through the actinomorphic-flowered ancestors of Grias<\/i> and Gustavia<\/i> that are in turn sister to the zygomorphic-flowered New World taxa.<\/p>\n On the other hand, surprises based on molecular data are making Lecythidaceae specialists more carefully evaluate some aspects of previous systematic accepted relationships of the family. For example, molecular data place Lecythidaceae in the Ericales (Anderberg et al., 2002; Morton et al., 1997; Sch\u00f6nenberger et al., 2005) even though a sister relationship based on morphology had never been hypothesized before. This may be a problem that will never be solved because it is not possible to obtain molecular data for all species of Lecythidaceae and their ancestors over the evolutionary time frame of Lecythidaceae.<\/p>\n Another unexpected result is the suggestion derived from the latest molecular phylogeny that Eschweilera<\/i> is not monophyletic (Mori et al., 2007). In the tree provided in that paper, Eschweilera appears as two unresolved clades \u2013 a large, wide-spread clade with seeds with lateral arils and a smaller clade with a more limited distribution in Central America, the Andean valleys, and western Amazonia having seeds surrounded by a spreading white aril that often completely surrounds the seed (see \u201cAril spreading\u201d in the Glossary Module). The morphological difference that we have found that separates the two clades is the lateral aril characteristic of the larger clade and the spreading aril of the smaller clade.<\/p>\n Zygomorphy is restricted to the New World Lecythidaceae and appears to have evolved once, but this interpretation requires a reversal back to actinomorphic flowers in theAllantom<\/i>a lineage (now including the actinomorphic-flowered Cariniana<\/i> discussed in Mori et al. (2007).<\/p>\n Molecular data applied to New World Lecythidaceae indicate that species in the generaAllantoma<\/i>, Corythophora<\/i>, Couratari<\/i>, Couroupita<\/i>, Grias<\/i>, and Gustavia<\/i> form well supported clades and that under the current circumscriptions Cariniana<\/i>, Eschweilera<\/i>, and Lecythis<\/i>are not monophyletic. Because the position of the monotypic Bertholletia excelsa<\/i> in relation to the other zygomorphic-flowered genera is not resolved, the final story about its generic relationships has not yet been established. A cladistc analysis of Cariniana<\/i>, however, clearly indicates that there are two groups in Cariniana<\/i> and that one of these groups is more closely related to Allantoma<\/i> than it is to the other species (true Cariniana<\/i>because it includes the type). Thus, Huang et al. (in press) have redefined Cariniana<\/i>such that half of the erstwhile Cariniana<\/i> (those with zygomorphic flowers) stay in the genus and the other half (those with actinomorphic flowers) are transferred to Allantoma<\/i>. This leaves only the question of monophylly in Eschweilera<\/i> and Lecythis<\/i> and the relationships ofBertholletia<\/i> and other zygomorphic-flowered genera to be determined. Thus, the questions \u2013 1) are Eschweilera<\/i> and Lecythis<\/i> monophyletic? and 2) what are the relationships among the zygomorpphic-flowered Lecythidaceae? are the most important questions that remain to be solved in the classification of Lecythidaceae.<\/p>\n We propose to tackle these problems in three ways by: 1) sequencing the ITS and MatK genes which have shown enough variation to distinguish closely related species in other studies and adding those data sets to those already obtained from the ndhF and trnL-F genes to generate hypothesized phylogenies, 2) hypothesizing a phylogeny based on anatomical and morphological data, and 3) combining the data sets from molecular sequences and from anatomical and morphological studies.<\/p>\n In addition to questions about classification, we will address hypotheses about character evolution. The combination of studying a family with relatively well-known natural histories of pollination and dispersal and the ability to hypothesize phylogenies based on trees generated from multiple data sets makes it possible to study co-evolution across an entire Neotropical plant family. Thus, my colleagues and I will address questions such as:<\/p>\n In conclusion, Neotropical Lecythidaceae provide an exciting opportunity to learn about the systematics and evolution of a ecological important group of tropical trees. We invite others to join us in this endeavor.<\/p>\n How to cite:<\/p>\n Mori, S. A., Chih-Hua Tsou, Arne Anderberg, Ya-Yi Huang & Ghillean T. Prance. 25 August 2010 onward. The Lecythidaceae Pages (https:\/\/sweetgum.nybg.org\/lp\/index.php). The New York Botanical Garden, Bronx, New York.<\/p>\n","protected":false},"excerpt":{"rendered":" By Scott A. Mori, Chih-Hua Tsou, Arne Anderberg, Ya-Yi Huang & Ghillean T. Prance Click on phylogeny of Lecythidaceae to retrieve papers related to this subject. A summary of these papers is provided below. All references cited in the essay … Continued<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-fullwidth.php","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/pages\/41"}],"collection":[{"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":6,"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/pages\/41\/revisions"}],"predecessor-version":[{"id":168,"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/pages\/41\/revisions\/168"}],"wp:attachment":[{"href":"https:\/\/sweetgum.nybg.org\/science\/projects\/lp\/wp-json\/wp\/v2\/media?parent=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n