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About Calflora

Species Information

Observation Library

Plant Name Library










  • collect and integrate plant occurrence data from disparate sources
  • provide centralized access to this data through a variety of web interfaces
  • provide online visualization tools for this data
  • allow users to download as much of this data as possible for their own analyses
The Collection

The collection includes various types of data -- herbarium specimen records, species lists compiled by botanists for known locations, rare plant occurrences documented by the Natural Diversity Database and the CNPS Inventory, vegetation survey data from the California Department of Fish and Game, and plot species lists from sampling projects carried out by land management agencies.

By providing ready access to all these types of occurrence data, the project seeks to facilitate research on questions related to biodiversity, ecology, and conservation, and help researchers use the full power of their geographic analysis and modeling tools.

Other Features

Name data-- When scientific names have changed, the user can see both the original name, and various current interpretations of the original name.

How Data is Assimilated

The intent is to provide a core set of data about each observation and enough information for the user to select only those records that are suitable for a given type of analysis. Links are provided to the data source for additional information whenever possible. We examine source data sets and extract:

  • a plant name and a location
  • basic information about the site if available
  • the source institution and individuals responsible for the observation
  • the method used by the observer or collector to identify this observation

(A description of the structure of the data is available here.)

Broader Goals

By providing ready access to plant occurrence data, we seek to facilitate:

  • Access to range and distribution information for California plants
  • Analysis of patterns in plant distributions and species diversity
  • Protection of plant diversity at local scales
  • Protection of geographic range and genetic diversity of native species, both rare and common


There are many ways to participate in the Calflora project. In an ongoing way, we need help with data entry (online, mostly checklist and survey data), photo editing (choosing photos for the Taxon Report pages), quality control of the software (beta testing new applications), and quality control of the data. With respect to quality control, please inform us if you see data that does not look quite right, or use a Calflora application that does not function properly.

If you have plant occurrence data you would like to contribute, or would like to participate in the Calflora project in some other way, please contact us.


When you see an observation of a plant at a certain location on Calflora, does it mean that the plant is (was) really there? Because Calflora collects data from diverse sources, each with their own strengths and weaknesses, there is some filtering of the data which you (the user) must do to make the best use of this data.

Here are some error conditions to watch out for:

  • the plant is erroneously identified
  • the record is incorrectly georeferenced (eg. the coordinates are not in the stated county)
  • the plant in question was actually cultivated, unknown to the observer or collector

Whenever possible, we try to identify such records and, with the help of local experts, to label them as suspect. This is an ongoing task, and new data continues to come in. Meanwhile, here are several strategies for determining the level of evidence for a plant at a location:

    1. The presence of a plant in an area will be reinforced by other nearby observations of the same plant. Look at the number of records for a particular plant in a particular area. As the observation database grows larger, this becomes an increasingly effective technique. For instance, if you see that there is only a single record for a particular plant in the area of interest, and it is far away from other observations of the same plant, you may choose to discount it. Some Calflora web applications are set up to enable this kind of filtering:
    • A Taxon Report page shows the number of observations per county.
    • From a Taxon Report page, run the County Distribution Analysis for a plant to see a county distribution map based on more than one observation or more than one source for each county.
    • In the What Grows Here? application, if you set "Minimum Observation Count" to two or more, you will eliminate single plant records from the plant list for the target area.
    2. Pay attention to documentation type, which ranges from specimen (potentially the most reliable), through documented and reported, to literature (the least reliable). A record is classified as literature, for instance, when the observer is not known.

    3. Pay attention to the individual observers and collectors responsible for a record. Some are more reliable at plant identification than others.

Calflora  -  1700 Shattuck Av #198, Berkeley, CA 94709  -  510 528-5426  -  CONTACT