Morphometric and molecular evidence delimit six species in Clematis reticulata s.l. (Ranunculaceae: Clematis subg. Viorna)
Data files
Nov 07, 2025 version files 59.38 KB
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Clematis_reticulata_master.xlsx
57.12 KB
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README.md
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Abstract
Clematis subgenus Viorna of North America currently consists of 21 species with most of the diversity found in the southeastern United States. Past taxonomic treatments of subg. Viorna have varied greatly, which has led to unclear species limits across multiple species complexes. Often recognized as a single, polymorphic species with a high degree of ecological amplitude, variation in the Clematis reticulata species complex has previously been attributed to phenotypic plasticity. A combination of herbarium specimen examination and extensive fieldwork led to formation of seven a priori morphological groups, or hypothesized taxa, in the C. reticulata species complex based on previously used and novel morphological characters. We employ an integrative approach to species delimitation with data from morphometric studies of herbarium and common garden datasets, as well as a phylogeny inferred from ddRADseq. Of the seven hypothesized taxa, six were supported by evidence from morphology and phylogeny with supporting biogeography, and ecology. Recognition of Clematis terminalis sp. nov. renders C. subreticulata comb. nov. paraphyletic. Because of its morphological, ecological, and phenological distinctiveness, it may represent a case of peripheral speciation by isolation. Four new species are recognized: C. arenicola sp. nov., C. cumberlandensis sp. nov., C. ouachitensis sp. nov., and C. terminalis sp. nov. Viorna subreticulata is given a new combination in Clematis and the newly defined C. reticulata s.s. is re-circumscribed. An updated dichotomous key, species descriptions, ecological notes, and distribution maps are provided.
Dataset DOI: 10.5061/dryad.d2547d832
Description of the data and file structure
This is the comprehensive morphometric dataset for the Clematis reticulata species complex.
Four tabs are present: HERB_FL is from herbarium specimens with flowers, HERB_FR is from herbarium specimens with fruits, HERB_VEINS is from vein characters collected from herbarium specimens, and GARDEN is all common garden data.
Files and variables
File: Clematis_reticulata_master.xlsx
Description: Four tabs are present: HERB_FL is from herbarium specimens with flowers, HERB_FR is from herbarium specimens with fruits, HERB_VEINS is from vein characters collected from herbarium specimens, and GARDEN is all common garden data. Missing data is indicated with a "NA".
Variables
- SAMPLE is the sample identifier, usually used to indicate the voucher associated with an herbarium specimen.
- STATE is the USA state abbreviation of where the sample originated
- COUNTY is the county where the specimen originated in each state
- GROUP is the hypothesized taxonomic entity as tested in the study
- INFPOS is a binary 0 or 1 value to indicate inflorescence position, 0 being axillary, 1 being terminal.
- PDC_PDU is the added length of the peduncle and pedicel. Units in mm.
- PDU is the length of the peduncle. Units in mm.
- SPL is the sepal length. Units in mm.
- SPW is the sepal width. Units in mm.
- W90LL is the ratio of the leaf width at 90% length to the total leaf length. Units is ratio.
- PTLU is the petiolule length. Units in mm.
- ANCOL is the anther connective extension length. Units in mm.
- STWD is the stem width. Units in mm.
- LFTH is a value between 0 and 5 (in 0.5 increments) to qualitatively assess relative leaf thickness.
- TLLF is leaf trichome length. Units in mm.
- TLSP is sepal trichome length. Units in mm.
- ACRT is achene rim width to achene width ratio. Units is ratio.
- ACLW is achene length to width ratio. Units is ratio.
- ACTL is achene tail length. Units in mm.
- AREAR is areole area. Units in mm2.
- VNWD is vein width. Units in mm.