Staff from the Arnold Arboretum of Harvard University and colleagues from the North America-China Plant Exploration Consortium are embarking this fall on a plant collecting trip in the Appalachian Mountains region, the conservation partnership’s first expedition in North America in its 30-year history. Our intrepid explorers—Head of Horticulture Andrew Gapinski, Propagator Sean Halloran, and Living Collections Fellow Jared Rubinstein—are sharing their experiences in the field through a series of blogposts. This is their sixth and final transmission; see the first, second, third, fourth, and fifth parts.


The last few days of our North American China Plant Exploration Consortium (NACPEC) 2019 North America Expedition took place in Washington, DC and Philadelphia, where we visited several other NACPEC member institutions and city sites with our visiting Chinese botanists.

After leaving North Carolina, we drove north to Washington, DC. We said goodbye to Angela at the gates of the National Arboretum (where she had to work at an event the very next day) and then I promptly dropped Sean’s water bottle into the sewer. Fortunately, with the help of the pole pruner, we recovered it.

Retrieving a water bottle from a Washington sewer
Sean fixes my mess on the street outside the US National Arboretum in Washington, DC. Photo by Jared Rubinstein

With that nightmare behind us, we enjoyed some sightseeing in the nation’s capital, including the White House; the Lincoln, Jefferson, and MLK memorials; and the National Mall. The next morning, we returned to the US National Arboretum for a tour from Kevin Conrad, Curator of the Woody Landscape Plant Germplasm Repository. A portion of the seeds we collected on our trip will end up with Kevin, where he will preserve them in the repository and disperse them to other scientists and horticulturists. Kevin guided us through the living collections at the Arboretum, with a special focus on the Chinese gardens.

Asia Valley at the US National Arboretum
Kevin Conrad (third from right) guides us through “Asia Valley” at the U.S. National Arboretum. Photo by Sean Halloran

Kevin also brought us into the repository itself to look at his stored seeds, as well as into the National Arboretum’s herbarium.

Kevin and the National Woody Landscape Plant Germplasm Repository
Kevin shows Kang and Xinfen his collection in the National Woody Landscape Plant Germplasm Repository. Photo by Jared Rubinstein

In the herbarium, which will also receive a voucher for every plant we collected on our expedition, we found a few vouchers from previous NACPEC expeditions to China, including some carrying Kang’s name!

Man looking at herbarium voucher
Kang admires a pressed Acer griseum specimen he helped collect in China at the U.S. National Arboretum’s Herbarium. Photo by Jared Rubinstein

Kevin also took us to the bonsai collection, and to his research plots in Beltsville, MD, before we continued north to Philadelphia.

Bonsai at the US National Arboretum
One of the many beautiful bonsai in the U.S. National Arboretum’s collection. Photo by Jared Rubinstein

One of the first things I noticed when we arrived in Philadelphia, much to my horror, was a dead spotted lanternfly. Spotted lanternfly is an invasive leaf hopper from China that is wreaking havoc on trees in the Philadelphia area. We saw hundreds of them all over the place, but the public seemed very well informed and tried to stomp them out wherever they encountered them. Part of my job at the Arnold is to prepare us for the eventual arrival of spotted lanternfly, so needless to say I was not happy to see one in the flesh.

Dead spotted lanternfly outside Philadelphia
Our first spotted lanternfly sighting, dead in the parking lot at our hotel outside of Philadelphia. Photo by Jared Rubinstein

On a happier note, we spent our next day in Philadelphia visiting the Morris Arboretum, guided by Bill Cullina, the Executive Director. We enjoyed seeing their giant katsura (Cercidiphyllum japonicum), and poking around the Fernery. In the production area, Sean stumbled upon a bald cypress (Taxodium distichum) growing from a seed he collected on a previous expedition.

Team and Bill Cullina at Morris Arboretum
Bill Cullina (second from left) and the group in front of the Morris’ huge katsura tree. Photo by Sean Halloran
Sean and bald cypress he collected
Sean is delighted to discover a bald cypress growing from seeds he collected on a previous collection trip at the Morris Arboretum. Photo by Jared Rubinstein

We also visited downtown Philadelphia and saw Independence Hall, the Liberty Bell, and more spotted lanternfly before our penultimate dinner together. To commemorate our expedition, we feasted on Sichuan food at a delicious Chinese restaurant in Chinatown. Kang, Xinfen, and Tao were in charge of ordering, and our tongues burned as a result.

Sichuan feast in Philadelphia's Chinatown
Feeling full after a giant Sichuan feast in Chinatown, Philadelphia. Photo by Jared Rubinstein

For our very last day together, we traveled to Longwood Gardens to meet Peter Zale, Associate Director, Conservation, Plant Breeding and Collections. Peter showed Longwood’s beautiful and recently renovated fountains, the conservatories, and his tissue culture lab, where plants of conservation concern can be kept alive for repropagation.

Giant water lilies at Longwood Gardens
Giant water lilies at Longwood Gardens. Photo by Jared Rubinstein

Finally, that afternoon we took our final journey as a group to Chanticleer Garden for a tour from Bill Thomas, Executive Director and Head Gardener. Chanticleer really blew us away—it was a perfect day and the perfect time of year to visit their 47 acres. As the sun set, we enjoyed a final glass of 啤酒 (beer) and reflected on an excellent trip together. Bill also autographed and shared copies of Chanticleer’s gardening book.

One of the beautiful views at Chanticleer
One of the beautiful views at Chanticleer. Photo by Jared Rubinstein
Bill Thomas shares The Art of Gardening book
Bill Thomas (second from left) shares a copy of The Art of Gardening with Kang, Tao, and Xinfen. Photo by Sean Halloran

The next morning, we all went our separate ways: Tao Deng flew back to China; Kang Wang headed to South Korea for another work trip; Xinfen Gao took the bus to New York City to visit the herbarium at the New York Botanic Garden; and Andrew, Sean, and I headed back to Boston and the Arnold Arboretum.

In all, we covered 3,442 miles in ten states and the District of Columbia. We made 100 collections of 91 plant species, as well as approximately 425 herbarium vouchers. We worked with botanists, scientists, and naturalists from universities, local land trusts, and the federal government, and hopefully continued to build strong relationships with other plantspeople around the country and the world.

Herbarium vouchers after the first few days of collection
Herbarium vouchers after the first few days of collection, compared with…
Vouchers amassed after three week expedition
…vouchers amassed after three weeks of collecting. Photos by Jared Rubinstein and Sean Halloran
The fruit of one of the many beautiful magnolias we collected.
The fruit of one of the many beautiful magnolias we collected. Photo by Emily Ellingson