Phylogeny of Eastern North American Coreopsis (Asteraceae‐Coreopsideae): insights from nuclear and plastid sequences, and comments on character evolution

Abstract

A molecular phylogenetic study of eastern North American Coreopsis and representatives of other genera of tribe Coreopsideae was conducted using combined sequences from nuclear ITS and two plastid regions (matK, rpl16). A total of 25-30 species has been recognized in five sections of Coreopsis in eastern North America. Based on morphological characters, these taxa have generally been considered a monophyletic group. Our well-resolved phylogeny supports the monophyly of sections that have been recognized in Coreopsis, but the sections collectively do not comprise a monophyletic group because species of north temperate Bidens occur within one of the two major Coreopsis clades. The most notable departure of present results from prior views of relationships among sections is the lack of a sister group relationship between sections Calliopsis and Eublepharis; the shared presence of four-lobed disk floret corollas had been used to support a close relationship between these two sections. Relationships within sections show both similarities and differences with the results of previous studies based primarily on morphological characters. Mapping of morphological characters used taxonomically in Coreopsis and related genera onto the phylogeny indicates that the evolution of these characters has been complex, and this compromises their value for defining monophyletic groups. Examples include the annual habit, alternate leaves, winged fruits, red or brown basal spots on the yellow ligules, and four-lobed disk floret corollas.

Coreopsis bakeri (Asteraceae; Coreopsideae), a new species from Florida, USA

“…Surveys of single samples of C. bakeri and C. lanceolata for several plastid spacer regions, including the rpl16 intron, trnF-trnL-trnL, and trnQ-rps16 regions gave identical sequences. The new data for the rpl16 intron, as well as for a portion of matK, failed to support the results reported by Crawford & Mort (2005) showing a sample of C. lanceolata as distinct from other members of C. sect. Coreopsis for these markers.…”

“…The nine species currently recognized in the section are native to eastern North America (Smith 1976;Crawford et al 1990). The section is well supported as monophyletic based on molecular sequence data (Crawford & Mort 2005), but there are few differences among individual species for the nuclear ribosomal ITS region (Schilling et al 2014). Many species of C. sect.…”

Phylogenetic Distribution and Identification of Fin-winged Fruits

“…Fin-winged achenes occur in various tribes. The phylogeny of tribe Heliantheae as reconstructed from nuclear and chloroplast DNA, indicates that winged fruits have evolved two or three times in Coreopsis (Crawford and Mort, 2005). The wings are thin and lack venation.…”

Life History Affects the Evolution of Reproductive Isolation Among Species of Coreopsis (Asteraceae)

“…Sequences of ITS-1, ITS-2, rpl16, and matK were produced previously for a study of phylogenetic relationships and morphological character evolution in the EC (Crawford and Mort 2005) and sequences of ITS-1, ITS-2, and rpl16 were produced for the WC (Mort et al 2004;Crawford and Mort 2005), in addition to morphological characters that were not used in the present analyses. PAUP* 4.0b10 (Swofford 2003) was used to derive pairwise ITS distances ( The maximum likelihood analyses were conducted separately for the EC and WC because these two clades are not particularly closely related in a larger phylogeny of Coreopsideae (Kimball and Crawford 2004; M. E. Mort and D. J.…”

“…Two clades in the plant genus Coreopsis (Asteraceae), which we will refer to as the eastern clade (EC) and western clade (WC), are ideal for examining correlations between genetic distance and reproductive isolation. Sequence data are available from recent molecular studies (Kimball and Crawford 2004;Mort et al 2004;Crawford and Mort 2005), and extensive data on reproductive isolation among species are available from the biosystematic studies of Smith (1974Smith ( , 1976Smith ( , 1982Smith ( , 1983Smith ( , 1984. Another attribute that makes these two clades attractive as study organisms is variation in life history, with each clade containing both annual and herbaceous perennial species.…”