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Allie_Caulfield via Flickr // CC BY 2.0

Show & Tell: The Blaschka Glass Flowers

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Allie_Caulfield via Flickr // CC BY 2.0

Leopold and Rudolf Blaschka, 19th century father-and-son glass craftsmen from Dresden, Germany, came from a family of glassblowers that stretched all the way back to 15th century Venice. The Blaschka glass flowers, the largest collection of which is held at Harvard’s Museum of Natural History, represent more than five decades of the Blaschkas’ best work. 

Leopold Blaschka, the father of the pair, began the scientific phase of his career by making models of sea-dwelling invertebrates. The mid-19th-century models echoed scientists’ new fascination with the gorgeous variety of ocean creatures (see, for example, fellow German Ernst Haeckel’s beautiful catalogs of sea invertebrates).

Leopold had been making glass eyes and blown jewelry, but transitioned to scientific production and began supplying museums and scientists with glass specimens. Glass cephalopods and radiolarians failed to rot the way real specimens did, and allowed a better view of the colors and structures of these invertebrates. In the 1870s, curious collectors could buy Blaschka glass invertebrates from Ward’s Natural History Catalogue for a few dollars—expensive by the standards of that day, but cheap compared to the price of an intact Blaschka model today.

One of the Blaschka Glass Invertebrates at Harvard. Image by sionnac via Flickr // CC BY-NC-ND 2.0

The Blaschka flowers were a second act—and a lucrative one. Charged with starting a teaching museum in 1886, George Lincoln Goodale, a botany professor at Harvard, hit upon the idea of asking the Blaschkas to make plants to use in botanical instruction. “It was through the untiring energy of Dr. Geo. L. Goodale,” wrote Walter Deane in the Botanical Gazette in 1894, “that these artists were induced to abandon their work of making glass models of animals … They were … finally persuaded, on their own terms, to give their entire time to this work.” Financially supported by Harvard, the Blaschkas sent shipments of these delicate flower models to the States twice a year. When Leopold died, in 1895, Rudolf continued to uphold their end of the contract.

The resulting group of Blaschka flowers is still at Harvard—4000 models, representing more than 830 species. The museum’s Frequently Asked Questions covering the collection includes the query, “Are they really glass?”—reflecting a healthy, and understandable, skepticism on the part of its visitors. (The answer: Yes, they’re really glass. Sometimes they have wire supports inside.)

Linden Tea via Flickr // CC BY-NC-ND 2.0

While the scientific value of this collection is largely moot—researchers have other ways to see botanical specimens now—the strange verisimilitude of the Blaschka flowers still has the power to move contemporary museum audiences. Today, the project seems both ambitious and foolhardy. The Blaschkas created beautiful objects, meant to represent fragile states of nature, freezing those states of bloom or rot in permanence; but the objects are, themselves, unbearably fragile, and it seems utterly improbable that so many should have survived. (As poet Mark Doty wrote, in a meditation on the Blaschkas’ work: “And why did a god so invested in permanence/choose so fragile a medium, the last material/he might expect to last? Better prose/to tell the forms of things, or illustration.”)  

The Corning Museum of Glass, which holds a smaller group of Blascka flowers and invertebrates, offers digitized images of some of the tools and dyes that the Blaschkas used to make their specimens, as well as many of the drawings the pair made while researching and designing their models. 

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Live Smarter
5 Trouble-Shooting Tips to Keep Your House Plant Alive
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Maybe you’ve heard that houseplants can help improve indoor air quality. Perhaps you’ve read that looking at plants can help you focus. Or maybe you just really like how that ficus looks in your living room. But buying a plant and keeping it alive are two different things, and the answer to your botanical woes isn’t always “don't forget to water it.”

Here are five green-thumb tips to make sure your plant stays as leafy green as it was the day you bought it.


You don’t want to neglect your plant, but it’s easy to go overboard with the watering can, and that can be just as harmful as forgetting to water your plant for weeks. A watering schedule can help you keep track of whether or not your plants need attention, but you shouldn’t water just because it’s Sunday and that’s when you usually do it. Before you go to water your plant baby, make sure it actually needs it.

Your plant’s water needs will vary based on the type of plant, its location, how old it is, and plenty of other factors, but there are a few rules of thumb that can put you on the right track. Lift the pot. If it’s heavy, that means that the soil is full of water. If it’s light, it’s dry. Dig a finger into the soil around its roots, making sure to feel beneath the surface. Still damp? Hold off. Dry? Grab the H2O.

If you really struggle to strike the right balance between too much and too little water, consider a smart plant system. And regardless of how often you water, make sure to use a pot with good drainage to prevent root rot.


Be aware of where your plant is situated in the room, and whether there might be any temperature extremes there. Is your fern sitting right above the radiator? Is your peony subject to a cold draft? Is your rosemary plant stuck leaning against a window during a snowstorm?

As a rule, most houseplants can handle temperatures between 58°F and 86°F, according to a bulletin from the University of Georgia. The ideal range is between 70°F and 80°F during the day, and between 65°F and 70°F at night. Below 50°F, sensitive plants can suffer damage to their leaves. However, as with most plant advice, it depends on the species—tropical plants usually do well in higher temperatures, and some other plants are happier in colder rooms.

If your sad-looking plant is sitting in the middle of a cold draft or right next to the heater, consider moving it to a different spot, or at least a few inches away. If it’s near the window, you can also draft-proof the window.


Be mindful of the kind of ecosystem that your plant comes from, and know that keeping it happy means more than just finding the right amount of sun. A tropical plant like an orchid won’t thrive in dry desert air. According to the Biology Department at Kenyon College in Ohio, a dried-out plant will look faded and wilting. You can immerse it in water to help it bounce back quickly. (Warning, though: A plant that’s getting too much moisture can look that way, too.)

If your home gets dry—say, when you have the heater on full blast in the winter or the AC on constantly during the summer—you’ll need to find a way to keep your plant refreshed. Your can buy a humidifier, or create a humidity tray by placing the pot on a tray of pebbles soaked in water. The plant will soak up the humidity as the water under the pebbles evaporates. You can also get a spray bottle and mist your tropical plants periodically with water. (But don't mist your fuzzy-leafed plants.)

Not sure how humid your house is? You can get a humidity gauge (known as a hydrometer) for less than $10 on Amazon.


Even if you do all of the above correctly, you can still struggle to keep a plant healthy due to infestations. Keep an eye out for common pests like spider mites, which will leave brown or yellow spots on leaves or make the plant’s color dull. If you discover these tiny mites (you may need to use a magnifying glass), wash your plant immediately with water to knock off as many mites as possible. Wash the plant with an insecticidal soap, too, but make sure the label says it’s effective for mites.


Healthy plants often outgrow their homes. if you notice that there are roots coming out the drainage holes at the bottom of your pot, or that water sits on the surface of the soil for a long time before draining down, or that your plant’s roots are coming up out of the soil, it’s time to upgrade to a bigger pot. Signs of a “root bound” plant whose root system is too big for its container can also include wilting, yellowed leaves, and stunted plant growth.

No matter what the size of your plant, it’s good to repot it once in a while, since the nutrients in the soil deplete over time. Repotting creates a fresh nutritional start and can help perk up unhappy plants.

If your plant looks unhealthy and you're still stumped, try consulting the website of a university horticulture department for other signs of plant distress and potential solutions.

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Rosimar Rivera Colón
Scientists Find Two New Species of Deadly 'Bird-Catcher' Trees
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Rosimar Rivera Colón

From car windshields to cats, birds around the world face plenty of mortal threats. But as IFLScience reports, avians in Puerto Rico have particularly unique forest foes that until recently were unknown to science. Deep in the island's jungles, researchers have discovered two new species of "bird-catcher" trees, bearing ripe, sticky fruits that—yes—can quite literally trap and kill birds.

As recently described in the journal Phytokeys, the trees—which are members of the genus Pisonia—produce fruits with viscous skins covered in tiny hooks. If a bird perches on the tree, a piece of fruit can stick to its body; when the bird flies off, it takes the fruit with it, potentially dispersing it somewhere else on the island. But if the fruits become too tightly affixed to birds, they can trap and kill their tiny transporters. Their tiny bones sometimes litter the trees' swollen roots, which wrap over rocks and are said to look like elephant feet. 

The trees' discovery has resulted in the long-due recognition of two overlooked female figures in Puerto Rico. The trees were given the names Pisonia horneae and Pisonia roqueae to celebrate the scientific contributions of Frances W. Horne (1873–1967), an American illustrator whose vibrant watercolors depicted hundreds of Puerto Rican plants; and Ana Roqué de Duprey (1853–1933), a Puerto Rican academic, writer, suffragist, and amateur ethnobotanist.

"It only seemed natural to name the two new species after these two extraordinary women who spent decades on large educational projects aimed to divulge botanical knowledge in Puerto Rico," study co-author Jorge C. Trejo-Torres said in a statement. "Just like the two large trees remained unrecognized by science until now, the enormous efforts of these two women, who dedicated part of their lives to botanical work, remained largely unrecognized by the community."

The infructescences of Pisonia roqueae

Jorge C. Trejo-Torres

The 'elephant foot' trunk of Pisonia roqueae

The 'elephant foot' trunk of Pisonia roqueae.

Jorge C. Trejo-Torres

[h/t IFLScience]


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