Help identifying layer/symbology used on World Street Map basemap

[JoanSteinbacher]

I am using ESRI's World Street Map and World Topographic Map basemaps in a web application.  I had a user ask what a specific layer is on the basemaps and I am unsure where it comes from or what it represents.  The symbology looks like vegetation on water (I've inserted an image of it from both basemaps).  Does anyone know what layer this is?  I've look at the documentation listed below but it's still  not clear to me what I'm looking at.  Are there any legends that list each layer with a description and symbology?  Thanks...

Documentation:

http://www.arcgis.com/home/item.html?id=3b93337983e9436f8db950e38a8629af http://www.arcgis.com/home/item.html?id=3b93337983e9436f8db950e38a8629af

http://help.arcgis.com/en/communitymaps/pdf/WorldStreetsMap_Contributors.pdf

[MelitaKennedy · Accepted solution]

I don't know how to figure out the layer or all the symbology that's being used, but this particular one is 'submerged swamp' or maybe just 'swamp'. Check USGS symbology. (2.05 mb PDF file)

[JoanSteinbacher]

Thanks Melita.  I got similar information from ESRI tech support yesterday.  Here's the information they provided:

“I would like to inform you that as this is a free basemap, it is meant for reference only, and therefore does not have a legend or key. With that being said, we know that if you are viewing the topographic map at 1:100,000 to 1:24,000 then you are actually viewing the National Geographic TOPO! maps which are seamless, scanned images of United States Geological Survey (USGS) paper topographic maps. I could only find the key to these maps from outside resources, and those were not authoritative resources such as National Geographic and USGS.”

And here's a link to the same information you provided from USGS, but html format instead of pdf.

Guide to USGS Topographic Map Symbols

After looking at the satellite imagery for the specific area my user was asking about, it appears that "Wooded marsh or swamp" is the most likely description.

Hope all this helps others.