National Wetlands Inventory
http://www.nwi.fws.gov/
USGS National Wetlands Research Center
http://www.nwrc.gov/
Society of Wetland Scientists
http://www.sws.org/
Association of State Wetland Managers
http://www.aswm.org/
EPA Office of Wetlands, Oceans, and Watersheds
http://www.epa.gov/OWOW/wetlands/
US Army Corps of Engineers
http://www.usace.army.mil
Army Corps of Engineers Waterways Experiment Station
http://www.wes.army.mil/
Wetland Publications
http://www.wes.army.mil/el/wetlands/wlpubs.html
Environmental Concerns, Inc.
http://www.wetland.org
Florida Center for Environmental Studies
http://www.ces.fau.edu/
The Wetlands Regulation Center
http://www.wetlands.com/
USDA-NRCS Hydric Soils of the United States Homepage
http://soils.usda.gov/soil_use/hydric/main.htm
USDA-NRCS Official Soils Series Descriptions
http://ortho.ftw.nrcs.usda.gov/osd/osd.html
Soil Science Society of America
http://www.soils.org/
Illinois State Water Survey
http://www.sws.uiuc.edu
USDA, ARS National Sedimentation Laboratory
http://www.sedlab.olemiss.edu
USFWS National List of Plant Species that Occur in Wetlands
http://www.nwi.fws.gov/ecology.html
(this page has the links to both the1988 list and the 1996 draft list)
USDA PLANTS National Database
http://plants.usda.gov/plants/
International Plant Names Index
http://www.ipni.org/