logo Calflora Plant Characteristics and Associations Help
This application shows additional characteristics of a plant,
including what other organisms are associated with the plant,
and factors that affect where the plant is likely to grow.

This application shows information about known associations between a plant and other organisms, including

  • pollinators
  • other beneficial insects
  • pest insects
  • bacteria (e.g. Pierce's Disease)
  • fungi (e.g. Sudden Oak Death)

The butterfly icon appears for plants known
to be attractive to benefical insects.

This data has been compiled from many sources.

Data about bees and other beneficial insects are from the Xerces Society. For purposes of this application, Xerces indicated which California plants are favored by native bees, bumble bees, honey bees, and predatory or parasitoid (beneficial) insects. Xerces also indicated which plants native bees are likely to use for nesting material.

More information about beneficial insects is available here:

Data about butterflies is from

Data on sharpshooters and Pierce's Disease is from

Data on Sudden Oak Death is from the

See also this List of References.

Metallic green sweat bee
© 2007 Gary McDonald

Climate Characteristics
Climate characteristic data per plant are the result of an analysis using PRISM Climate Group's various datasets, which are discussed more fully in Background Layer Help.

For instance, the Annual Precipitation factor represents the range of annual precipitation at locations where this plant has been observed growing wild, according to Calflora records.

The range of annual precipitation for Rhamnus ilicifolia is given as

      9 to 73 inches

(or something close to that). These numbers were obtained by examining all high quality georeferenced records of this plant in California, deriving the annual precipitation for each location from the PRISM data, and then saving the high and low end of this range.


Annual Precipitation (min / max)

Wet Season (number of months: min / max)

Max Temperature Range

July High Temperature

December Low Temperature

Growing Season (number of months: min / max)

Accumulated Temperature (min / max)

USDA Hardiness Zone (min / max)

Soil Characteristics
Soil characteristic data per plant are the result of an analysis using NRCS SSURGO Soil Survey data, which are discussed more fully in Background Layer Help.

For instance, the Minimum Depth factor represents the minimum depth of the soil (centimeters) at locations where this plant has been observed growing wild, according to Calflora records. (If there is enough plant location data behind this number, the implication is that the plant needs this depth of soil in order to grow.)


Min Depth

pH (min / max)


Max Salinity

Max CaCO3 Equivalent

Both climate and soil characteristics represent a hypothetical abstract description of the conditions where a particular plant grows in the wild. They are subject to revision as 1. more high quality plant location information becomes available, and 2. the derivation algorithms are fine tuned.

Currently, the cutoff point for "enough" location data points to derive the various factors reliably is arbitrarily set at 50. (If there are fewer than 50 data points, the factor is still derived, but it appears with a warning: "the value shown is likely to be overly narrow," meaning that it has little predictive utility.) Because the SSURGO polygons can be very small, a higher standard of location accuracy is used for soil factors than for climate factors. Consequently, soil factor data is available for fewer plants than climate factor data.






USDA PLANTS Conservation Plant Characteristics
This effort was inspired by the conservation plant characterics developed by USDA PLANTS.


Plant Location Suitability is a separate application which compares the actual climate and soil characteristics of a location with the tolerances of a particular plant. There is a link to this application from the Taxon Report page and the Plant Characteristics page.

Use: Select a location by clicking on the map. The application shows plant tolerances and location factors side-by-side, and will highlight any factors of the location which are not suitable for the plant.

This application can help determine whether it is appropriate to plant a certain native plant at a certain location. It is still experimental, and sometimes results require interpretation.


Rhus aromatica, Fragrant sumac

Solidago spathulata, Dune goldenrod

Ribes sanguineum, pink flowering currant

Rubus armeniacus, Himalyan blackberry

Rubus parvifolorus, thimbleberry

Rhus aromatica
© 2005 James Andre

2016 November 6 In version 0.75, the various factors are shown in both American units (inches, feet, degrees Fahrenheit) and metric units (meters, centimeters, degrees Centigrade).