Carnivorous Plants - Kew Gardens

The quiet streets of Kew.

I had initially planned to begin my trip here but after scheduling conflicts, Kew now serves as a fitting conclusion to my journey of discovery. As perhaps the largest and most diverse single collection of plant species and specimens in the world, Kew has played an important role in the history of botany and carnivorous plants. Upon arriving at Kew Station, a short 30-minute train ride from my hostel to the outskirts of London, I walked over to the renowned garden’s main entrance. My first encounter with carnivorous plants at Kew was actually in their visitor's shop, strategically located at the entrance/exit area. Unlike the wild types on display, the plants for sale here have been bred to exaggerate their most interesting features (large traps, bright red streaks, etc.). But as I had found with the displays at Down and Cambridge, the very things that make them desirable as novelty purchases often lead to a premature demise. Signs warn against attempting to touch or feed the plants, as too much contact inevitably kills them. Kids convince their parents to buy them a cool living souvenir, but proceeding to poke and prod the plants’ sensitive traps, their new plaything rarely lasts long (I myself was admittedly guilty of this not too long ago).

I spent the entire first day of my visit exploring Kew’s most famous greenhouses. As one of The Royal Botanic Gardens ”Crown Jewels,” the towering two-story Palm House seems to come right out of a Victorian picture book; a massive glass structure bordered by a carefully manicured rose garden on one side and a flock of geese relaxing in a picturesque pond on the other. I was transported from a slightly brisk and cloudy afternoon to a tropical jungle with thick columns of vegetation towering above the meandering visitors. The Temperate House was even more gorgeous, with several interconnected glass wings and an ongoing blown glass exhibition by the artist Chihuly seamlessly merging with both the architecture and vegetation. It is also home to a new exhibit on the trade of rare plants on the black market, and Kew’s role in plant conservation. They remain deeply involved in preventing the illegal trading of plants (including those of the carnivorous variety) in England; working to examine, identify and occasionally adopt plants smuggled into the country (usually bound for elsewhere in Europe). They are also attempting to sequence the genomes of all tropical pitcher plants (Nepenthes) to better understand and protect endangered species’ natural habitats. Although carnivorous plants were front and center for this exhibit, the permanent carnivorous displays (some of the largest in the world) are held in two separate rooms of the Princess of Wales Conservatory; one for cool, temperate plants and one for those of the warm, tropical variety (almost exclusively Nepenthes). The cool room houses the most diverse display, with butterworts, temperate pitcher plants, sundews, and of course a number of Venus Fly-traps lining the glass walls.

The Palm House

Temperate House

Commonly smuggled plants

The Princess of Wales Conservatory - Warm Carnivorous Plants Room 

The temperate exhibit also expands upon and challenges common ideas about plant carnivory, including plants that employ a range of chemical and physical defense mechanisms to kill pests, but without a means to extract nutrients from their prey (unless you count them as soil fertilizer). Spending what probably seemed like an oddly long time in these rooms, I overheard plenty of interesting conversations about these plants (not in a creepy way, I promise)! Whether it was adults explaining how these plants work to their children, or more often vice versa, it was great to get exposure to the almost universal fascination with these plants amongst the many ages, languages, and backgrounds trickling through the exhibits. It was also interesting to hear some recurring myths about these plants, some of which were almost exactly the same as those addressed by Hooker in his speech nearly 150 years prior. For example, the idea that the lids of pitcher plants act in the same way as a Venus Fly-trap’s snap trap, tightly encasing prey in the digestion chamber. Of course, we now know this isn’t the case, and these are actually passive pitfall traps; but appearances can be deceiving, and it was so cool to see the same idea pop up in such different contexts.

A small sample of the collection.

Darlingtonia californica

Of the materials I checked out in the Kew Archive the one that stuck out most to me was a compilation of publications on plant carnivory by various people and from various sources between 1873-77. This document illustrates the explosion of international scientific work in the years immediately surrounding the publication of Insectivorous Plants. I think one of the most important documents was an address given by Hooker, during his time as director of Kew, to the Dept. of Zoology and Botany of the British Association. Darwin had spoken of his work with Drosera at the Royal Society nearly a decade earlier, and Hooker seemed inspired by his close friends renewed fervor for the subject, incorporating a broad range of historical sources in his speech and pointing towards the importance of future research with these plants. There was also a diverse range of studies on sundews in French, German, Italian, and English, accompanied by illustrations. Additionally, I found an extensive set of watercolor copies of Utricularia (bladderworts), along with a paper first describing the discovery of Darlingtonia californica, the California cobra lily, and some really cutting edge work at the time comparing the electrical impulses of Dionaea muscipula to those found in human muscles. Earlier work with carnivorous plants has been generally more difficult to find, but I’ve had some luck with accounts in early plant encyclopedias in Harvard’s Gray Herbarium Botany Library.

Experiments with Utricularia

1597 illustration of a sundew

After some phone tag and scheduling conflicts, I ended up meeting with Tomas Pickering, the supervisor of the temperate nursery and carnivorous plant aficionado, on my second day at Kew. He showed me around the huge nursery collection, which houses the majority of species at Kew. It is home to many species of both temperate and tropical carnivorous plants, most of which don’t make it to the public displays. Some of the more interesting examples included Nepenthes lowii, a tropical pitcher plant that supplements its carnivorous diet with tree shrew droppings, and Nepenthes hemsleyana, which acts as a highly adapted roost for a specific species of tropical bat. I learned about the great lengths Kew goes to in order to ensure that these specimens are coming from responsible sources, and discussed the ongoing Nepenthes genome sequencing project. Having led many Kew-funded research expeditions to Madagascar, Mr. Pickering was also able to relay a bit about the fascinating myths surrounding a fictional man-eating tree used for human sacrifice by native tribes. Entirely fabricated by colonial Australian explorers in Madagascar, this tale may actually be based on a real-life tree, Pisonia brunoniana, known to ensnare birds in its sticky foliage.

In case my photography of carnivorous plants at Kew isn’t up to scratch, there are some beautiful pics of the nursery collections on his Insta @pickleplants

But carnivorous plants exist beyond laboratory greenhouses and the enthusiasts’ garden as a social phenomenon. From the famous sci-fi musical Little Shop of Horrors to John Wyndham's Day of the Triffids, these plants have enjoyed their share of the limelight. Of the countless organisms we share our planet with, few have permeated the public’s consciousness in the way the Venus Flytrap and its insectivorous brethren have. These plants violate deeply inscribed knowledge about the natural order of the food chain, and that shock factor alone makes them an indispensable tool for the modern greenhouse in engaging with the public interest. This experience has allowed me to better understand the scope of these plants’ impact on botany, and the huge cast of characters involved in global scientific efforts to understand these curious contraptions of nature. But it has also offered a glimpse at their past, present, and future potential to captivate audiences around the world. I look forward to continuing my exploration of something that so perfectly represents the strange and beautiful possibilities of the natural world.