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.

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A BSTRACTMany long-lived perennial spe cies exhibit lowered reproductive capacity. Early studies of reproduct ive success in Dedeck era eurek en sis (Po lygonacea e) demonstr ated that the spe cie s e xhibited extremel y low reproducti ve su cce ss , low see dlo vule (S/O ) ratios (i.e., the percentage of ovules that produce filled seeds; 2.5 %), low germinability of filled seeds (3.5%), low seedling survivorship (11 .1% ), and lack of recruitment in natural populations. These results were attributed to genetic load , but thi s eli c ited co ntrove rsy , prompting long -term stud ies of the re lationshi p between the SIO ratio and en vironment. After nine year s o f monitoring, how ev er, the SIO ratio had not changed signifi cantly (2 .7%), and there was no significant correlation between precipitation and the SIO ratio. Controlled field ex perime nts dem on strated that neither resource ava ilability nor other eco logica l factors significantly influenced embryo abortion rates . Controlled se lf-po llinatio ns (N = 115) matured only one qu estionably filled seed , whereas intrapopul ation cro ss-pollination s (N = 192) produced signifi cantly mor e seed (S/O = 12.0 % ) . Previ ou s pollination studies demonstrated that the species has no primary poll inators and is onl y rarel y visited by a few gene ra list insects. However, the flower s typi call y se lfpoll inate in 2-3 da ys foll owing anthesis. Strong infe rence suggests that the loss of reproducti ve capacity in D. eurekensis may be the result of inbreeding depres sion due to the superimposition o f se lfpollination on a norm ally outcrossed species carr ying a high gen eticlsegregational load .

Speciation not associated with morphological shifts is challenging to detect unless molecular data are employed. Using Sanger-sequencing approaches, the Lomatium packardiae/L. anomalum subcomplex within the larger Lomatium triternatum complex could not be resolved. Therefore, we attempt to resolve these boundaries here. METHODS:The Angiosperms353 probe set was employed to resolve the ambiguity within Lomatium triternatum species complex using 48 accessions assigned to L. packardiae, L. anomalum, or L. triternatum. In addition to exon data, 54 nuclear introns were extracted and were complete for all samples. Three approaches were used to estimate evolutionary relationships and define species boundaries: STACEY, a Bayesian coalescent-based species tree analysis that takes incomplete lineage sorting into account; ASTRAL-III, another coalescent-based species tree analysis; and a concatenated approach using MrBayes. Climatic factors, morphological characters, and soil variables were measured and analyzed to provide additional support for recovered groups. RESULTS:The STACEY analysis recovered three major clades and seven subclades, all of which are geographically structured, and some correspond to previously named taxa. No other analysis had full agreement between recovered clades and other parameters. Climatic niche and leaflet width and length provide some predictive ability for the major clades. CONCLUSIONS:The results suggest that these groups are in the process of incipient speciation and incomplete lineage sorting has been a major barrier to resolving boundaries within this lineage previously. These results are hypothesized through sequencing of multiple loci and analyzing data using coalescent-based processes.

A high degree of morphological variability exists within Lottiatiutii (biscuitroots, Apiaceae). This variability has led to conflicting opinions regarding relationships of white-flowered Lomatium specimens from southern Idaho and Oregon allied to L. nevadense and L foeniculaceum. An initial morphological study, using morphometric analysis and phenetic classification techniques, suggested that these anomalous specimens, generally referred to as L. ravetiii, were more closely related to L. foeniculaceum than to L. tiei'adense. Phylogenetic analyses using the rpsl6 intron, ITS, and rpl32-trnL^^,^,. placed five populations of the anomalous individuals within a clade including L. ravenii and the three varieties of L. foeniculaceum from our region. However, two populations collected from Succor Creek in southeastern Oregon clustered independently of L. ravenii, suggesting a new cryptic species. Subsequent morphological analyses revealed differences in morphology between L. ravenii and the Succor Creek populations. We propose a new Succor Creek endemic species, L. bentonitum.

Molecular and morphological phylogenetic analyses indicate that many of the perennial endemic genera of North American Apiaceae are either polyphyletic or nested within paraphyletic groups. In light of these results, taxonomic changes are needed to ensure that ongoing efforts to prepare state, regional, and continental floristic treatments of Apiaceae reflect recent findings. Thus, six new combinations are made to accommodate the movement of five taxa from their current assignment into the genus Lomatium and the elevation of one variety of Lomatium to the level of species; Lomatium lithosolamans, Lomatium tenuissimum, Lomatium fusiformis, Lomatium linearifolium, Lomatium multifidum, and Lomatium planosum.

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