[R-sig-Geo] spplot() - "grouping variable"

[Ingo Holz]

Hi,

 I use spplot to display the values of a SpatialPointsDataFrame.

 spplot(SPDF[,"var1"], col.regions=rainbow(100), pch =16)

 I have different types of locations (forests, pastures, etc) and would like to 
change the "point character" (pch) according to this "grouping variable". Is 
this or something like this possible?

 Thank you for your help!

 Ingo