logo Calflora Plant Distribution Help
This application shows the range of a particular plant in California as either
a distribution grid:
or as a set of observation points:

To use the application, begin by dragging the map to an area of interest,
and then zoom in to look at the data in more detail.

After dragging, click on the map to search for observations in the current map area.
The point where you click is indicated by a red cross .



As you zoom in, the size of the grid cells is set automatically. The size of a grid cell is reported as, for instance, 15 arc minutes or 1 arc minute. 1 arc minute means that each side of a cell is 1/60 of a degree in length. Use the minus and plus buttons to adjust cell size.

When you click on a grid cell, an info window appears showing how many observations are within that cell, and offering a link to see the actual observations.

Cells are colored to form a heat map indicating the density of observations. Cells with one or two observations are yellow, cells with a medium number of observations are orange, and cells with a high number of observations are red. The heat map coloration is most useful when zoomed out, as an indication of where a plant has been most studied.

Note that the application begins by showing the Terrain map type. When you want to zoom in closer than the Terrain map type will allow, switch to the Satellite map type (upper right).




When the application first comes up, it displays a distribution grid of the whole state, and reports how many records are available in the map area. As you zoom into an area of interest, the number of records reported goes down. When the number records found in the map area is 1500 or less, you can check the Observations radio button to display individual observations. (Due to browser memory constraints, the application can only show 1500 observation points at a time.)

When you click on an observation point , an info window appears showing a summary of the observation, and offering a link to see full details of the observation.


When you click on this link, the current state of the page is added to your browser's URL. After pressing this link, you can

  • use the browser to bookmark the URL;
  • copy the URL and email it to someone; or
  • use the browser's back button later to return to this state.

Add an observation of ...
Click on this link to add an observation of the plant using Plant Observation Entry.

Observation Hotline
Click this link to bring up the Observation Hotline application, and see if any Calflora contributors have added observations of this plant with photos.

View ... in Google Earth
Click this link to bring up Google Earth showing the same data. Lines and polygons are included when available.

Mentzelia laevicaulis
Giant Blazing Star
© 2011 Orrin Winton

See also About Layers. When you choose a background layer such as Watersheds, the application will report the name of the watershed where the center mark is located. Click on the various watersheds to see their names.

If the Precipitation background layer is showing, you can click on the map to see average annual precipitation at that point .

Super Planning Watershed:
Tassajara Hot Springs 3309.6003

Line and polygon data is available for certain weeds. If data is available, a Lines and Polygons checkbox appears. Check this box, and the available shapes will be drawn on the map. Shapes appear as shown on the right. Note that most lines and polygons are tiny, so that you must zoom way in to see them. Switch to the Satellite map type to zoom very close.

To make it easy to find the shapes, the application indicates
shape observations with this marker: ,
and point observations with this marker: .


Polygon: Line: