Shrubland vegetation was called "scrub" on some older USGS legend sheets. As noted above, scrub is a dry-climate vegetation (but not a specific species). It covers many hills in southern California and similar arid areas. The pattern appears on the maps as randomly spaced green dots; the dots do not represent individual plants.
Earlier you looked at the Inverness, CA quadrangle (see right) because it showed part of the San Andreas Fault. Look at it again for its vegetation representations. The map shows extensive wooded highland areas with the solid green symbol. It also shows what appears to be a lighter green symbol to represent shrubland, called "scrub" in the western US; you have to zoom in very close to see that it is actually a pattern of random dots, not a solid color at all.
(7.5 x 7.5 minutes, but download an older, pre-2000 map)
Look closely at the vegetation for the "scrub" or shrubland areas.
Two forms of planted vegetation are shown on USGS maps: orchards and vineyards. I will leave it to you to learn the difference between an orchard and a vineyard, if you dont already know it. In terms of the symbols, though, note the differences in size and spacing of the green dots. Most maps that have either orchards or vineyards will not have both orchards and vineyards, so it will be important to be able to tell which you are looking at.
The map fragment linked at right shows part of California's Central Valley, and major fruit producing area of the US. Look for the orchards and vineyards on this map segment. Please note that the redness that appears mixed with the green in the orchard and vineyard dots is due to the quality of the scan taken by the USGS.