Botanicus Digital Library: free accessible, Web-based encyclopedia of historic botanical literature from the Missouri Botanical Garden Library.
BPH Online: searchable database of plant science periodicals published from 1665 to present.
CalFlora Database: native and introduced wild plants in California. Species accounts include CA distribution, habitat, specimen information, and links to the Jepson Manual entries.
efloras.org: search selection of online floras with detailed botanical descriptions from around the world.
ePIC, Electronic Plant Information Centre (Kew): search Kew Royal Botanical Gardens’ checklists, databases, bibliographies, and publications. Particularly useful for taxonomic queries: search the International Plant Names Index and checklists.
Jepson Flora Project: includes the Jepson eFlora - the Flora Project site links to numerous databases and manuals. The eFlora, based on the Jepson Manual, has species accounts including distribution maps and botanical descriptions of California plants.
JSTOR Global Plants: online archive of plant specimens, photographs, drawings, prints, paintings, articles, correspondence, reference works, and other materials.
Subjects include logging operations, logging equipment, reforestation, forest research, fire protection, lumber mills, and the activities of the University of California's School of Forestry. The photographs were taken from 1906 to 1984 by Emanuel Fritz, Woodbridge Metcalf and others.
The collection can be searched by keyword, location, year, and more.
American Woods, "exhibited by actual specimens and with copious explanatory text by Romeyn Beck Haugh." [Digital version from North Carolina State University Libraries' Special Collections Research Center.]