Botanical review and CEQA
California native plants need an extra set of eyes on all environmental review. Very often, plant data is incomplete or insufficient for a number of possible reasons, including:
- Seasonality and natural phenomena – Previous surveys may have been conducted when a plant was dormant or not easily recognizable due to growing seasons, drought, or other natural conditions.
- Databases – Reference databases are positive occurrence databases and the lack of occurrences does not indicate that a rare species is not present, only that it has not been documented. These databases also often have considerable backlogs in updating plant occurrence data so reference materials may be out of date.
- Expertise – Often plant surveys are conducted as a component of surveys focused on other resources. The person who conducted surveys may not have been a trained botanist, or the survey may have been timed to best identify a resource other than the rare plants with the potential to occur on the project site.
For all these reasons, CNPS staff and native plant advocates must understand the environmental review process and know how to address common information gaps.
How review begins
CEQA requires a full environmental review of a proposed project site. As a first step, a consulting biologist will undertake a desktop review of which species would have the potential to occur on the project site. To do this, they use the U.S. Geological Survey’s unit system of land measurement for the U.S. known as “quads.” Short for quadrangle, each quad has a corresponding name and number. The quad map of California provides a uniform way to talk about different parts of the state.
For environmental review, the standard is to perform a nine-quadrant (quad) query of the area surrounding the project location. This would include the quadrants, where the project is located and all adjacent quads. The nine-quad search is a useful baseline to understand the plants and habitats that might exist on a project site, but any agency review should rely heavily on physical surveys and an additional layer of plant-focused review is helpful. That’s where CNPS — and you — come into the picture.
Where and how to conduct plant searches
Select from the options below for instructions and helpful tips to identify potential plants in proposed project areas.

Online databases
A wealth of information is publicly available. Learn which resources to trust and how to use them.

Local knowledge
Not everything is mapped, so local experts and information is often critical to filling in the gaps.

Visiting the project site
If you have access and the knowledge, a site visit is one of the best ways to verify what plants and habitats exist