Like clockwork this December: every Tuesday has brought snow, at least for the first three weeks. If the pattern keeps up, a fresh dusting will arrive on New Year’s Eve, transforming the Arboretum landscape, on the first of the year, into a hushed and brilliant scene. I can imagine neighbors walking though, for fresh air, while bean pots simmer at home. The background hum of the roads—Centre Street, the Arborway—would be absent, the roads quiet, while most people stay home, playing board games or searching for missing jigsaw pieces. One hundred years ago, however, the Arboretum was not an altogether quiet place. Rather, on New Year’s Day in 1920, Arboretum staff were sorting through a shipment of seeds that had arrived from China. It was a collection from the Belgian railroad-engineer-turned-plant-collector named Joseph Hers, which are now among the most curious wild-collected members entering the Arboretum’s new centenarian class.
The first plant collections from Hers were accessioned in late December of 1919—some, in fact, on New Year’s Eve—and others were officially recorded over the next few days. The Arboretum’s founding director, Charles Sprague Sargent, was exceptionally impressed by Hers’s work. “This is one of the most important collections of Chinese plants which has been sent to the Arboretum,” Sargent wrote in 1919, after reviewing an initial list of plants that Hers offered to provide. An unusual Miquel linden (Tilia miqueliana, accession 12211*A) and Chinese zelkova (Zelkova sinica, accession 12215*A) are among five Hers plants turning 100 in 2020, but the most impressive of the cohort is a Hubei wingnut (Pterocarya hupehensis, accession 15390*B), which stands in the back corner of the hickory collection. This tree is the only representative of the species planted in the Arboretum collections, although material from a 2018 expedition is currently working its way through the nursery. On a recent snowy afternoon, the twin trunks of Hers wingnut struck an impressive pose—upright, with one trunk popped akimbo, like a fashion model posing at the end of the runway, hand on hip, one knee bent.
Wingnuts are members of the walnut family (Juglandaceae), but the fruits scarcely resemble those of their more common relatives. Instead of large animal-dispersed fruits—the kind of things that squirrels stockpile in the fall—wingnut fruits (technically nutlets) are dispersed by the wind. The nutlets hang in long chains, and each has two broad, rounded wings on either side, protruding like ears on a cartoon elephant. At this point in the winter, the namesake wingnuts are scarce on the Hers tree. All but a few have fluttered free, although the thread-like chains remain, suggesting an abundant crop. Even with this ability to produce copious fruit, recent evaluations of the species’ distribution in central China have suggested that fewer than 100 populations remain, with relatively little seedling regeneration at those sites.
The Hers wingnut overlooks a secluded glade at the Arboretum, which is hemmed with assorted winterhazel species (Corylopsis) on one side. These shrubs look especially stunning in the snow—zigzag stems, frosted with thick piping; copper heart-shaped leaves clinging here and there; and the buds luminous and yellow, already hinting at the burst of early spring color. Three of the winterhazels (accessions 10156*D and 10544*A and B) arrived from Ernest Henry Wilson’s final plant collecting expedition to eastern Asia, which ended in 1919. In 1920, Wilson, then the assistant director of the Arboretum, embarked on an expedition to Australia, India, and South Africa, along with other countries that would form the British Commonwealth. Wilson’s two-year expedition would produce photographs, herbarium specimens, and books for the library, but he returned with little in the way of plants and seeds that would survive in Boston. Without an official Arboretum staff member in China, Sargent was especially eager to collaborate with individuals like Hers.
Hers—who would ultimately send nearly 350 unique collections to the Arboretum—had an unconventional path into the world of plant exploration. He had arrived in Shanghai in 1905, where he was employed as a translator for the Belgium Ministry of Foreign Affairs. In 1913, he became the secretary general for a Belgian-backed railroad company in northern China. In that capacity, he began studying the trees, partially due to their material importance for constructing the railroad but also because he perceived that the region might harbor species that were interesting—even new—to American and European botanists. “My own knowledge of botany is, I regret to say, very limited,” Hers wrote to Sargent in 1919, “but as I happen to live in a part of China where very few botanical collections, if any, have been made, and as I enjoy frequent opportunities to travel in little known districts, I have thought it while to collect specimens of all woody species growing here.” The Hers wingnut, in that sense, is a testament to the value of a self-proclaimed scientific dilettante—the power of curiosity and the legacy of someone asking questions about the world around him. How’s something like that for a New Year’s resolution?