The Glass Flowers, formally The Ware Collection of Blaschka Glass Models of Plants, is a famous collection of highly realistic glass botanical models at the Harvard Museum of Natural History at Harvard University in Cambridge, Massachusetts, one of the Harvard Museums of Science & Culture.
They were made by Leopold and Rudolf Blaschka from 1887 through 1936 at their studio in Hosterwitz, Germany, near Dresden. The collection was commissioned by Professor George Lincoln Goodale, the first director of Harvard's Botanical Museum, to aid in teaching botany and was financed by Mary Lee Ware and her mother, Elizabeth C. Ware. There are 847 life-size models representing 780 species and varieties of plants in 164 families as well as over 3,000 models of details such as enlargements of plant parts and anatomical sections. Approximately 4,300 individual glass models comprise the collection.
The models are made out of glass but other materials were used in their construction including wire for internal support, a variety of organic media, and paint. In an article for the Journal of American Conservation, authors McNally and Buschini note that "the Glass Flowers are not made simply of glass. Many are painted (particularly models made in the years 1886–95) and varnished; some parts are glued together, and some of the models contain wire armatures within the glass stems. Coloring of the models ranges from paint to colored glass to enameling." To this day, no one has been able to duplicate the Blaschkas' fine artistry.
Rumors of a secret glassworking process employed by the Blaschkas have been around as long as the models have. The Blaschkas actually practiced techniques that were common to glassworkers of the time but what set them apart was their own astonishing skill in glassworking, meticulous dedication to the study and observation of nature, and enthusiasm for the subject matter. The Blaschkas practiced lampworking, a glassworking technique in which glass is melted over a flame fed by air from a foot-powered bellows. The melted glass is then shaped using tools to pinch, pull or cut and forms can be blown as well. As oil lamps were replaced by modern gas-fueled torches, lampworking has come to be referred to as flameworking or torchworking. 
Botanist Donald Schnell gives testimony to the astonishing accuracy of the models. He writes of a plant, Pinguicula, the details of whose pollination were unknown. By painstaking analysis of its structures, he worked out the probable mechanism of pollination. On visiting the glass flowers exhibit for the first time in 1997, he was enjoying the "enchanting and very accurate" models, when he was astonished to see a panel showing Pinguicula and a pollinating bee: "one sculpture showed a bee entering the flower and a second showed the bee exiting, lifting the stigma apron as it did so," precisely as Schnell had hypothesized. "As far as I know Professor Goodale never published this information, nor did it seem to have been published by anyone back then, but the process was faithfully executed."
In the Journal of American Conservation, authors Whitehouse and Small state that "the superiority in design and construction of the Blaschka models surpasses all modern model making to date and the skill and art of the Blaschkas rests in peace for eternity."
The Glass Flowers are one of the most famous attractions of the Boston area. More than 210,000 visitors view the collection annually. In 1936, when Harvard invited the public to tour the campus in honor of its tercentenary, a New York Times reporter taking the tour commented "Tercentenary or no, the chief focus of interest remains the famous glass flowers, the first of which was put on exhibition in 1893, and which with additions at intervals since, have never failed to draw exclamations of wonder or disbelief from visitors."
A visitor returning to Back Bay in 1951 after a ten-year absence wrote "I was told the two sights above all others that visiting salesmen from the country wish to see when in Boston are the glass flowers at the Harvard Museum of Natural History in Harvard Square and the Mapparium at the Christian Science Church building."
Marianne Moore wrote in a poem, "Silence,"
My father used to say,
"Superior people never make long visits,
have to be shown Longfellow's grave,
or the glass flowers at Harvard."
Prior to making the Glass Flowers, the Blaschkas established a very successful business supplying collections around the world with glass models of marine invertebrates. Cornell University has some on display  but most of their models are stored at the Corning Museum of Glass in Corning, New York . Other locations exhibiting the Blaschka invertebrates include:
- Boston Museum of Science (USA)
- Harvard Museum of Natural History (USA)
- Natural History Museum, London (UK)
- National Museum of Ireland (Ireland)
- Redpath Museum of McGill University, Montreal (Canada)
- Natural History Museum of Geneva (Switzerland)
- Hancock Museum, Newcastle upon Tyne (UK)
- Aquarium-Museum of Liège (Belgium)
- NcNally, Rika Smith and Nancy Buschini (1993). Journal of the American Institute for Conservation, Volume 32, Number 3, Article 2 (pp. 231 to 240)
- "Glass Dictionary". Corning Museum of Glass. Retrieved 6 August 2013.
- Schnell, Donald (2002). Carnivorous Plants of the United States and Canada. Timber Press. ISBN 0-88192-540-3.
- "Back to Back Bay After an Absence of Ten Years". The New York Times. June 10, 1951, p. XX17.
- The Ware Collection of Blaschka Glass Models of Plants Harvard website
- Invertebrate Models at Cornell University
- "Glass Flowers bloom again at HMNH", Harvard University Gazette
- "'Glass Flowers' gallery to close for renovations", Harvard University Gazette
- "Care for Glass Flowers branches out: Natural History Museum's fragile flowers get needed cleaning and repair", Harvard University Gazette
- "These creatures see dusty duty: Obscure cousins of the Glass Flowers depict denizens of the deep", Harvard University Gazette
- "Eclipsed for decades, Harvard's glass animals step out", Harvard University Gazette
- Corning Museum of Glass