Polyploid.net - Patrick Alexander's photos of plants and other items. Strong focus on New Mexico.
Vascular Plants of the Gila - Russ Kleinman's galery of plants from the Gila and beyond.
SEINet - The Southwest Environmental Information Network. Data from most of the larger herbaria in the southwest.
New Mexico Rare Plants Website - Compilation of information on rare taxa in New Mexico. Compiled by the New Mexico Rare Plant Technical Council.
New Mexico Native Plant Society - Chapters distributed throughout the state.
Museum of Southwestern Biology - University of New Mexico natural history museums.
Lulu.com - A number of important New Mexico resources have typically been available through Lulu.com. Look for books by Kelly Allred. Flora Neomexicana is now out (August 2012).
Flora of North America - Available e-floras from FNA.
International Code of Botancial Nomenclature (2007)
Intermountain Flora Database - New York Botanical Garden
Trees and Shrubs of New Mexico - Jack Carter's 2012 revised work!