The Glass Flowers

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The Glass Flowers collection at the Harvard Museum of Natural History contains over 800 species and cultivars, including full-sized models and hundreds of microscopic plant parts.
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The Glass Flowers collection.
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The Glass Flowers collection.
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This glass version of ‘Shortia galacifolia’ was crafted by Rudolf Blaschka in 1893.
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The Glass Flowers collection.
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The Glass Flowers collection.
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The Blaschkas' workbench and glassworking tools are on display with the Glass Flowers collection.
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Leopold, Caroline, and Rudolf Blaschka at their home in Germany. A long-standing family trade, their lineage of glassmakers and jewelers can be traced back to the 15th century.
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The Blaschkas crafted this model of Gossypium herbaceum in 1893.
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Kalmia Latifolia has showy flowers and glossy leaves. This glass version was crafted by Rudolf Blaschka in 1900.
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A glass ‘Alexander’ apple, depicted with an apple scab infection.
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Created in 1892, this model shows Brugmansia arborea before the species became extinct in the wild.
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A glass model of Monarda didyma, crafted by Rudolf Blaschka in 1903.
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A sketch of Monarda didyma.

Crafted more than a century ago, Harvard’s Glass Flowers still elicit gasps of disbelief from viewers. There’s a stem of scarlet bee balm (Monarda didyma) so realistic it looks like it might actually smell of citrus and oregano if rubbed hard enough; a branch of mountain laurel (Kalmia latifolia) that a florist could convincingly place side-by-side with fresh blooms; and a tiger orchid (Rossioglossum grande), pollinated by glass bees whose wings seem to whir.

Artists Leopold and Rudolf Blaschka’s approximately 4,300 other botanical models also stun. From 1887 until Leopold’s death in 1895, the father and son glassworkers devoted their lives to reverse engineering the world’s flora and reconstructing them in glass at their studio and garden near Dresden, Germany.

After Leopold’s death, Rudolf continued to make glass models for Harvard until 1936. The Blaschka methods, inherited through several generations of glassworkers, allowed them to make such realistic models that botanists have been shocked to see them accurately depict details that weren’t published scientifically until more than a century after their creation.

Almost from the beginning, the Blaschkas’ Glass Flowers earned a reputation as their best work, and some of the greatest examples of glass artifice ever created, drawing more than 300,000 visitors a year to the Harvard Museum of Natural History, where the collection is housed. Many artists have tried to match them without success. Even modern technology fails to reproduce the Blaschkas’ handiwork exactly — the fine detail and naturalistic translucence of glass is difficult even for 3D printers to replicate.

As species diversity decreased over the past century, the Glass Flowers evolved into more than a breathtaking garden of re-created heirloom plants perennially in bloom. They became a window into a lost world, and a potential horticultural touchstone. The Glass Flowers collection, formally known as The Ware Collection of Blaschka Glass Models of Plants, contains more than 800 species and cultivars, representing six continents. Of those, more than 160 are threatened or extirpated in parts of their natural range, and at least 20 are now endangered globally. More than just immortalizing them in glass, the Blaschkas’ work has the potential to help preserve and protect the plants they so carefully depict. 

Angel’s Trumpet (Brugmansia arborea)

Status: Extinct in the wild

Although this South American native is cultivated for its rich eau de cologne fragrance and perpetual flush of white, trumpet-shaped flowers, no natural populations exist. Would-be sightings have been of hybrid forms and other species of Brugmansia and Datura that escaped from gardens. To add to the confusion, no herbarium specimens have ever been collected from verified wild plants. Because of the plant’s mystery and spotty documentation, the Blaschka model has special value as a reference. Created in 1892 after Rudolf observed the species in cultivation in Jamaica, it documents with hyper-realistic detail plants that were grown under this name more than 120 years ago, before it vanished from its natural range.

B. arborea and other closely related Brugmansia species, which are all extinct in the wild, can be grown as tall perennials in Zones 9 through 11, and in Zone 8 with protection. In colder areas, the plants grow as smaller annuals. When Rudolf saw B. arborea in Jamaica, his hosts grew it around verandas, where the brilliant flowers stood out during evening piano soirees, memorably perfuming the balmy spring air. 

‘Alexander’ or ‘Emperor Alexander’ Apple (Malus pumila)

Status: In cultivation

 ‘Alexander’ is a large Ukrainian apple from the 1700s with a sweet, slightly aromatic flavor and skin splotched with impressionistic shades of green and red. The glass model illustrates an apple scab infection (Venturia inaequalis).

While nurseries still sell ‘Alexander’ and many of the other heirlooms in the Glass Flowers collection, the 67 fruit models might be used to verify their identities — what’s sold today may not be the same as the cultivar known by that name in the 1920s and 1930s. According to Maine apple expert John Bunker, the staple fruit is one of the most difficult to identify, considering there were once 17,000 cultivars. Tom Burford, a Virginia apple connoisseur, confesses that many identifications remain educated guesses, even for those in commerce. One reason for the large margin of error is that explorers seeking out forgotten fruits often rely on old nursery catalogs and books with vague descriptions and images. Models in the Glass Flowers collection offer perfect replicas for an apples-to-apples comparison. Bunker says he has considered following the Blaschkas and creating models of the rare apples he preserves, too. 

Roughbark Lignum-Vitae (Guaiacum officinale)

Status: Endangered

Even national flowers are not safe from commercial overexploitation and habitat loss. Native to the Caribbean, the Bahamas, parts of South America, and Florida, Jamaica’s iconic plant produces one of the hardest woods in commerce, as well as a resin that’s harvested for its medicinal properties. The species has been shipped internationally for centuries, and although trade is now closely regulated, the trees are slow-growing, so wild populations can be challenging to re-establish.

Roughbark lignum-vitae’s low cold tolerance limits it to Zone 9 or warmer, but it makes a spectacular evergreen landscape tree where it can be grown. Its rounded canopy repeatedly blooms with bright blue flowers that develop into ornamental orange fruit.

One potential use of the Blaschka models for studying species such as G. officinale is to revisit the populations they were modeled from to look for phenotypic changes, or to see if the populations still exist at all. 

Oconee Bells (Shortia galacifolia)

Status: Endangered

Long elusive in its small natural range in the American South, the imperiled evergreen ground cover is being squeezed out further by habitat loss. While its dark green foliage and dangling bell flowers make it superb for woodland gardens, it’s hard to grow, and few nurseries carry it.

The plant can occasionally be found growing wild along streambanks in moist, wooded areas, though it’s rare to see. The easiest specimen to find might be the one Rudolf crafted in 1893 for Harvard. But anyone who responsibly obtains a specimen without stripping a wild colony has garden bragging rights. 

Great St. John’s wort (Hypericum ascyron)

Status: Extirpated or at-risk in seven states

Some endangered species may come as a surprise. This native St. John’s wort is commercially available, and its smaller Eurasian sibling, common St. John’s wort (Hypericum perforatum), is a ubiquitous garden plant recognized as a noxious weed by some and a beneficial medicinal by others. More than 160 species in the Glass Flowers collection are globally secure, such as great St. John’s wort, yet struggling in large swaths of their natural range. For these species that still have strong wild populations, the Glass Flowers’ celebrity appeal can be used to create awareness and help prevent locally endangered populations from becoming globally endangered. As a start, gardeners who enjoy the cheery yellow blooms of common St. John’s wort as an ornamental can instead plant this native, pollinator-friendly version, noting that its medicinal properties differ from those of H. perforatum. 

Benjamin is a garden writer who became fascinated with the Glass Flowers while researching roses at the Arnold Arboretum of Harvard University. 

Learning Tools

Though Leopold Blaschka inherited his glassworking techniques, nothing foreshadowed the scientific precision of his models. He was such a gifted artist and student of natural history, in fact, that others encouraged him to break from family tradition and become a painter. While he instead chose to continue with his father, making costume jewelry, ornaments, and glass eyes, he immersed himself in plants and animals on sketching trips.

After observing jellyfish during a sea voyage, Leopold had an idea: The flameworking and jeweling methods that had been passed down to him might be refined to capture plant and sea life better than sketches or paintings. Leopold’s first attempts to re-create elaborate bouquets of flowers in painted glass caught the attention of a wealthy nobleman in 1857. A market for his models steadily developed among the aristocracy, followed by natural history museums and universities across the world.

Leopold’s glass sea creatures filled a growing niche: Marine invertebrate specimens did not retain a lifelike appearance for classrooms or displays. Joined by his son and protégé Rudolf, Leopold provided a solution with their flawless glass re-creations. One of their American catalogs featured 700 marine models.

In 1886, a would-be patron showed up at Leopold’s studio with a seemingly laughable offer. George Goodale, the first director of Harvard’s Botanical Museum, asked the Blaschkas to give up their successful marine invertebrate business to make glass plants exclusively for Harvard. After some haggling and a part-time trial period with the artists, Goodale got what he wanted.

Thanks to the Glass Flowers, students and visitors have been able to study life-sized plants in bloom any time of the year — with enlarged models substituting for microscopic views — and at the same time, celebrate the Blaschkas’ perfectionist obsession with the natural world.

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