Try Tri again? Resolving species boundaries in theLomatium triternatum(Apiaceae) complex

Abstract

Species boundaries have traditionally been delimited by applying phenotypic characters to a morphological species concept. With an increased understanding of the complexities of speciation as a process, species concepts have proliferated while at the same time, the ability to gather greater numbers and types of molecular characters has expanded the means by which species can be delimited. Phylogenetic studies of molecular data provide an opportunity to identify reciprocally monophyletic groupsand have led to the identification of cryptic or nearly cryptic species in which subtle differences in phenotypes or ecological niches can be uncovered only after monophyletic groups have been identified. Here, we investigate evolutionary relationships among a group of species in the Lomatium triternatum complex using molecular phylogenetic analyses for all samples, and ecological parameters for two of the 38 species included in this study. The results indicate that there are more reciprocally monophyletic groups in this complex than had been estimated using phenotypic data alone. The ecological data show a clear differentiation for the one pair of sister species where ecological sampling was available, implying that divergence within this group may have resulted from environmental selection for soil preferences that have been strong enough to result in speciation.

Resolving species boundaries in a recent radiation with the Angiosperms353 probe set: the Lomatium packardiae/L. anomalum clade of the L. triternatum (Apiaceae) complex

“…In the current study, we recovered clades that agree with described species (Lomatium packardiae) or geographic regions (Figs. 2, 3) that were not recovered in any prior molecular analysis (George et al, 2014;Smith et al, 2018a) or identifiable with keys based on morphological data (Hitchcock and Cronquist, 1973;Cronquist et al, 1997). Previous studies using Sanger-based sequencing that…”

“…The four southern subclades are also part of a polytomy; however morphologically and geographically, L. packardiae and the East-Central Oregon populations are more similar, and likewise, the Mann Creek and Hell's Canyon populations are more similar. In an earlier study, Smith et al (2018a, see their fig. 3) found that according to leaflet morphology, L. packardiae and the Mann Creek/Hell's Canyon separated into two forms, Form A and Form B, respectively.…”

“…have sampled far more individuals than were included here were sufficient to recover several clades (Smith et al, 2018a), but unable to resolve boundaries among accessions of L. packardiae and L. anomalum. In addition, our current results resolve taxonomic puzzles that Smith et al (2018a) identified, such as the sister group relationship of L. packardiae (Carlson 097) with that of L. triternatum (Mansfield 16078). These two collections are separated geographically by nearly 200 linear miles and are morphologically distinct in terms of leaf width and fruit length.…”

“…Recent investigations into the Lomatium triternatum (Pursh) J.M.Coult. & Rose species complex have revealed a suite of homoplasies and incongruencies between morphological and molecular data (Smith et al, 2018a ). Lomatium simplex (Nutt.…”

Species delimitation in the genus Greenwayodendron based on morphological and genetic markers reveals new species

“…Until now, the majority of plant species have been delimited by taxonomists based on morphological analyses of character variation (morphological species concept, MSC) (Lewin, 1981;Henderson, 2005;Smith & al., 2018). However, this approach to species delimitation presents many shortcomings either due to intra-specific morphological variation or little morphological difference between closely related species (Pratt & Clark, 2001;Whittall & al., 2004).…”