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Taxonomic Implications of Morphological Variation in Cercis canadensis (Fabaceae) from Mexico and Adjacent Parts of Texas

Fritsch, Peter W.; Schiller, Anja M. and Larson, Keith LU (2009) In Systematic Botany 34(3). p.510-520
Abstract
Taxonomic treatments recognize three varieties of Cercis canadensis: with variety canadensis, widespread throughout the eastern United States, and varieties texensis and mexicana, found east and west of the Pecos River in Texas, respectively. The distribution of Cercis continues southward into northeastern Mexico, but complex variation in leaf shape has confounded straightforward application of varietal names to the Mexican plants. To clarify the taxonomy of Cercis in Mexico, we conducted a morphometric analysis with 281 herbarium specimens, including a representative set of samples from Texas. Correlation and principal component analysis of 12 characters recovered two groups that correspond to the presence versus absence of branchlet... (More)
Taxonomic treatments recognize three varieties of Cercis canadensis: with variety canadensis, widespread throughout the eastern United States, and varieties texensis and mexicana, found east and west of the Pecos River in Texas, respectively. The distribution of Cercis continues southward into northeastern Mexico, but complex variation in leaf shape has confounded straightforward application of varietal names to the Mexican plants. To clarify the taxonomy of Cercis in Mexico, we conducted a morphometric analysis with 281 herbarium specimens, including a representative set of samples from Texas. Correlation and principal component analysis of 12 characters recovered two groups that correspond to the presence versus absence of branchlet pubescence. These groups are geographically distinct at the northern and southern extremes of the focus area but exhibit a large central region of overlap. No other discontinuities in character states were discovered to corroborate this division. Leaf shape varies continuously from ovate-acuminate at the northern and southern extremes to subreniform in the central region, suggesting clinal adaptation to the mesic versus xeric environments in which the plants occur. Based on Our data, we apply the varietal epithets mexicana and, provisionally, texensis to Mexican C. canadensis with pubescent and glabrous branchlets, respectively, the latter based on geographic proximity to plants in Texas in the absence of definitive evidence on the phenotypic distinction between varieties canadensis and texensis. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
morphometrics, elliptic Fourier analysis, adaptation, cline, redbud, taxonomy
in
Systematic Botany
volume
34
issue
3
pages
510 - 520
publisher
American Society of Plant Taxonomists
external identifiers
  • wos:000269770000008
  • scopus:70349486035
ISSN
0363-6445
language
English
LU publication?
yes
id
9ad4dc39-5720-4eea-9811-7323ffcdf7cc (old id 1490856)
date added to LUP
2009-10-19 11:02:45
date last changed
2017-08-13 03:56:51
@article{9ad4dc39-5720-4eea-9811-7323ffcdf7cc,
  abstract     = {Taxonomic treatments recognize three varieties of Cercis canadensis: with variety canadensis, widespread throughout the eastern United States, and varieties texensis and mexicana, found east and west of the Pecos River in Texas, respectively. The distribution of Cercis continues southward into northeastern Mexico, but complex variation in leaf shape has confounded straightforward application of varietal names to the Mexican plants. To clarify the taxonomy of Cercis in Mexico, we conducted a morphometric analysis with 281 herbarium specimens, including a representative set of samples from Texas. Correlation and principal component analysis of 12 characters recovered two groups that correspond to the presence versus absence of branchlet pubescence. These groups are geographically distinct at the northern and southern extremes of the focus area but exhibit a large central region of overlap. No other discontinuities in character states were discovered to corroborate this division. Leaf shape varies continuously from ovate-acuminate at the northern and southern extremes to subreniform in the central region, suggesting clinal adaptation to the mesic versus xeric environments in which the plants occur. Based on Our data, we apply the varietal epithets mexicana and, provisionally, texensis to Mexican C. canadensis with pubescent and glabrous branchlets, respectively, the latter based on geographic proximity to plants in Texas in the absence of definitive evidence on the phenotypic distinction between varieties canadensis and texensis.},
  author       = {Fritsch, Peter W. and Schiller, Anja M. and Larson, Keith},
  issn         = {0363-6445},
  keyword      = {morphometrics,elliptic Fourier analysis,adaptation,cline,redbud,taxonomy},
  language     = {eng},
  number       = {3},
  pages        = {510--520},
  publisher    = {American Society of Plant Taxonomists},
  series       = {Systematic Botany},
  title        = {Taxonomic Implications of Morphological Variation in Cercis canadensis (Fabaceae) from Mexico and Adjacent Parts of Texas},
  volume       = {34},
  year         = {2009},
}