Biodiversity Heritage Library (BHL) is offered by a consortium of 12 major US and UK botanical and natural history libraries with a collection of 46,000-plus titles and 90,000-plus volumes. The biodiversity-related items range in date from 1450 to the present. The collection is patron driven; patrons may request items to be scanned into the digital library. This feature is particularly helpful for scholars who cannot physically travel to view rare documents. The scans are high quality, but some images are slightly crooked or off-center. However, this does not significantly affect the documents’ readability. The download options are extremely helpful: individual pages, PDF, OCR, images, bibliographic information, or all options.

Users may browse by Titles, Authors, Subjects, Map, and Year, and limit by language and contributing institution. Searching can be slightly puzzling to the untrained eye. A simple keyword search returns just a few of the possible results, and one must click through the results to get to the content. This is not a problem for experienced searchers, but undergraduates may have some difficulty deciphering the first results. A variety of search options enhance browsing of the thousands of freely available documents. One such feature permits the creation of a full bibliography with links to the full text. One may easily link to an entire bibliography using a specific URL, with the addition of a genus and species or family name. This option streamlines the search process, allowing researchers to easily determine the usefulness of BHL to their own research. The site has a rich infrastructure encompassing wikis, blog content, developer tools, tutorials, and more. This growing online library for the modern scholar would be an especially compelling addition to a library’s discovery service. Summing Up: Highly recommended. Lower- and upper-level undergraduates; graduate students. — J. Clemons, College of Wooster