Wildflowers of the United States

Reference List for South Dakota Wildflower Identification
Site	Description
The Great Plains Native Plant Society	Mission To engage in scientific research regarding plants of the Great Plains of North America; To carry on the scientific work begun by Claude Barr of Prairie Gem Ranch, Smithwick, South Dakota, which is to pursue greater knowledge, appreciation and understanding of the Great Plains of North America; To disseminate this knowledge through the creation of one or more educational botanic gardens of plants of the Great Plains, featuring but not limited to Barr's discoveries; To engage in any educational activities which may further public familiarity with plants of the Great Plains, their uses and enjoyment.
Wildflowers and Grasses of South Dakota - a set on Flickr	A set of 76 South Dakota and Wyoming wildflowers on Flickr, taken by soniawc. Thumbnails are ordered by the date the photo was taken. Many of the species are identified, but some are not.
Fontenelle Forest NatureSearch - Wildflowers	From the site: "We've identified close to 300 species of wildflowers so far by walking the trails and prairies of Fontenelle Forest and Neale Woods... To help in searching for a particular species page, the wildflowers are separated by color, and within each color category by the approximate date they first bloom. But be aware that intermediate or variable colors do occur..." Recommended by Rachel Hall, this appears to be an excellent site for wildflower identification for Nebraska, especially the eastern part of the state, along with the nearby states of SD, IA, KS, and MO.
Lady Bird Johnson Wildflower Center at the University of Texas at Austin	Perhaps the most comprehensive native wildflower information site in the United States. "Discover more than 10,050 plants native to North America."
USDA Plants Database	Great resource for native plants! Their own description: "The PLANTS Database provides standardized information about the vascular plants, mosses, liverworts, hornworts, and lichens of the U.S. and its territories." Provides these important (to me) pieces of info: 1) Listing by state and county within a state where specific species have been identified. 2) Scientific name synonyms are listed. 3) Scientific names are matched to a widely-used common name. 4) Photographs of many species. 5) State by state list of all the species identified in that state. Official Citation: USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 22 June 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Flicker Wildflower Field Guide, North America	Over 9,000 Flickr member photos tagged with wfgna. The WFGNA group has good tagging requirements for their excellent photos, so you'll find, in addtion to the photo, the state in which the photo was taken, and at least a common name and the scientific name as identified by the contributor. After you get to the linked page you should add search criteria, including the state name, the color of the plant, or scientific name, to reduce the number of photos. Several states have several hundred photos(California has over 1,500!) so you'll probably want to add color to the search criteria.
WildflowerSearch.com	Steven K. Sullivan has done a tremendous job of putting together a database and search engine to help in identifying wild plants. Not only can you search by plant scientific and common names, you can narrow the results using location (currently lower 48 states and parts of Canada and Mexico), flower shape, color, size, habitat, and observation time. His database currently includes over 7,000 plants. Definitely worth checking out.
Wildflower Information.org	From the site: "WildflowerInformation.org is a resource for wildflower enthusiasts and gardeners. With a growing interest in the environment and natural gardening, our objective is to offer comprehensive information that is easy to use, and accessible for those from the casually interested to the expert." While this information doesn't appear to be on the website itself, WildflowerInformation.org seems to be owned by American Meadows, the "recommended wildflowers seed supplier" of WildflowerInformation.org.
Item at Amazon: National Audubon Society Field Guide to North American Wildflowers--E: Eastern Region - Revised Edition (Commission to USWildflowers.com if purchased)	"...gives full descriptions of more than 650 species found east of the Rocky Mountains, along with notes on several hundred more. The eminently sensible organization relies on first-impression visible characteristics..." I use this guide frequently, and unless I have a good idea what family a flower is in, this is usually still my first stop. In my opinion, a must-have for beginning wildflower enthusiasts; augments more locale-specific wildflower references.

Looking for Wildflowers for a specific state? Check here: Number of References for South Dakota: 9