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Core Eudicots: Dicotyledons V
Published in Donald H. Les, Aquatic Dicotyledons of North America, 2017
The Menyanthaceae (bogbeans) are a well-defined family consisting of about 80 species worldwide. All members are insect pollinated, aquatic, or semiaquatic herbs that inhabit freshwater lakes, ponds, and wetlands (Kadereit, 2007; Tippery et al., 2008). The three North American genera consist entirely of OBL species and the remaining species in the family also are helophytes or hydrophytes. Menyanthaceae once had been regarded as closely related to (or even part of) Gentianaceae (Lindsey, 1938); however, contemporary phylogenetic analyses consistently place the family firmly within the Asterales, in a position remote from Gentianaceae (Downie & Palmer, 1992; Judd & Olmstead, 2004; Judd et al., 2008; Tank & Donoghue, 2010). The chemistry of Menyanthaceae also differs from that of Gentianaceae, by its discordant flavonoid profile (Bohm et al., 1986) and lack of the cyclitol L-(+)-bornesitol, which is prevalent throughout the latter (Schilling, 1976). Menyanthaceae clearly are monophyletic and resolve as a clade when analyzed using ndhF, nrITS, rbcL, or trnK/matK sequence data in conjunction with numerous Asterales outgroup genera (Olmstead et al., 2000; Tippery et al., 2008). At a higher taxonomic level, the family consistently resolves within an “MCGA” clade (Figures 5.132 and 5.180) comprising Menyanthaceae, Goodeniaceae, Calyceraceae, and Asteraceae, based on analyses employing data from multiple nuclear and chloroplast loci as well as morphological characters (Olmstead et al., 2000; Albach et al., 2001; Lundberg & Bremer, 2003; Judd & Olmstead, 2004; Tank & Donoghue, 2010; Maia et al., 2014).
Cladistic methods as a tool for terrane analysis: a New Zealand example
Published in New Zealand Journal of Geology and Geophysics, 2018
Bernard Michaux, Malte C. Ebach, Elizabeth M. Dowding
Cladistics was developed in biological systematics as a way of grouping objects (usually but not exclusively species) in such a way as to minimise conflicting evidence (Schuh and Brower 2009). The results of such analyses are usually presented as branching diagrams (‘trees’) in which objects are grouped according to shared characters (e.g. presence of feathers). Cladistics differs from phenetic methods (based on overall similarity) in that only derived characters are used to discover these groupings. Character polarity (i.e. whether the character is derived or primitive) can be determined in several ways, most commonly by using an outgroup. The character state of an outgroup becomes the primitive state for the ingroup. A node is formed at the junction of branches, and all objects connected to any node form a monophyletic group, sometimes referred to as a clade. The identification of monophyletic groups is the primary aim of cladistics because such groups are natural in the sense that they are not artefacts but the products of evolution.