Skip to main content

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

Buy Article:

$23.00 plus tax (Refund Policy)

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.

Keywords: ADAPTATION; CLINE; ELLIPTIC FOURIER ANALYSIS; MORPHOMETRICS; REDBUD; TAXONOMY

Document Type: Regular Paper

DOI: http://dx.doi.org/10.1600/036364409789271254

Publication date: July 1, 2009

More about this publication?
aspt/sb/2009/00000034/00000003/art00008
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more