A Newly Described Serpentine-Endemic Ceanothus (Rhamnaceae) From Coastal Marin County, California

  title={A Newly Described Serpentine-Endemic Ceanothus (Rhamnaceae) From Coastal Marin County, California},
  author={V Thomas Parker},
Abstract Ceanothus decornutus V. T. Parker is a newly described species found on serpentine outcrops in western Marin County. This taxon has been considered as part of C. jepsonii Greene in recent treatments. Ceanothus decornutus differs in a number of ways from C. jepsonii and suggests relationships to other northern San Francisco Bay species. Beyond the species description and a key to similar taxa north of San Francisco Bay, an analysis of leaf characters is used to indicate possible… 
Three Edaphic-Endemic Ceanothus (Rhamnaceae) New to Science
Three new taxa of Ceanothus are described, two initially noted among existing collections, and another discovered during botanical exploration in San Diego County, which are edaphic micro-endemics found only in the southern California Floristic Province, California.
A Taxonomic Conspectus of Ceanothus Subgenus Cerastes (Rhamnaceae)
To aid research in this diverse and ecologically important group of plants, a taxonomic conspectus is presented, including formal recognition of Cerastes at the rank of subgenus, and recognition of all infraspecific taxa at theRank of variety.
Chaparral of California


Edaphic Ecology and Genetics of the Gabbro-Endemic Shrub Ceanothus roderickii (Rhamnaceae)
Analysis of data indicates that evolution of C. roderickii was associated with specialization to nutrient-deficient forms of gabbro-derived soil, a result that is consistent with reinforcement.
Diversification of Ceanothus (Rhamnaceae) in the California Floristic Province
The reconstructed evolution of Ceanothus is reconstructed by using DNA sequence data from the nuclear gene nitrate reductase to find that the timing of diversification events is related to geological and climatic history.
Limited hybridization across an edaphic disjunction between the gabbro-endemic shrub Ceanothus roderickii (Rhamnaceae) and the soil-generalist Ceanothus cuneatus.
There is little genetic exchange between the focal species across an edaphic disjunction, despite the absence of prezygotic barriers, implying that soil conditions, as well as other extrinsic factors, should be considered as forces that may restrict hybridization and gene flow in Ceanothus, influencing local adaptation and speciation.
Morphological and Molecular Analysis of Putative Hybrid Speciation in Ceanothus (Rhamnaceae)
All four entities in the North American shrub genus Ceanothus are found to be closely related genetically, with the alternative hypothesis of primary allopatric divergence just as reasonable an explanation for the data.
Diversification of the North American shrub genus Ceanothus (Rhamnaceae): conflicting phylogenies from nuclear ribosomal DNA and chloroplast DNA.
The degree to which matched independent data sets can produce conflicting summaries of evolutionary history is demonstrated, including nuclear and organellar phylogenies, which exhibited very low levels of both topological and character congruence.
Molecular phylogeny of the genus Ceanothus (Rhamnaceae) using rbc L and ndh F sequences
The phylogenetic results suggest that three monophyletic clades within the subgenus Ceanothus can be delimited on the basis of evergreen or deciduous leaves and thorn presence within the evergreen clade.
Sepals, petals 6(–8); fruit with prominent wavy ridges, horns wrinkled
  • 2014