This and That: Travels of Sophora toromiro

Toromiro, Sophora toromiro (Phil.) Skottsb, collected 28 June 1800, H. Herrenhus. [possibly Hannover Herrenhausen Royal Gardens], Germany. CC BY-NC-ND 4.0. Te Papa (SP107845)

As with most of the posts in this series of miscellanea (see last post), this story begins with a Tweet, one linked to a blog post and a research article connecting four countries over 250 years.  I’ll try to keep it as simple as possible, by starting in the middle.  In 1877, James Hector, director of the Colonial Museum in New Zealand (now the Museum of New Zealand: Te Papa), asked the British Museum (BM) for a collection of European plant specimens to compare with European plants colonists had brought into the country and were now flourishing, sometimes to the point of being nuisances.  Hector received 28,000 specimens collected by three British amateur botanists: a husband and wife, Silvanus and Bridget Thompson, and Thompson’s student, James Baker.  Most specimens were from cultivated plants gathered in German botanic gardens and the Cels nursery in France between 1764-1864.  Hector never got around to sorting through this gift from the BM; it remained in its original packaging until the 1950s; even today, the only vascular plants to be processed are the orchids.

Recently six specimens of Sophora were found in the collection.  Sophora is a small genus of 17 species in the Fabaceae family and native to the South Pacific.  With eight species, New Zealand is its center of diversity, hence the interest in these sheets that were dated from 1796 to 1822 and were presumably from cultivated plants.  This was surprisingly early for Sophora to be growing in Europe.  Until now, it was thought that the Sophora in Europe were all descended from seeds collected from the 1920-1950s.  There was little plant collecting in the South Pacific until the early 1800s, though Joseph Banks and Daniel Solander had gathered seeds of two Sophora species on Captain James Cook’s first round-the world voyage.  These were planted at Kew by 1772, and there were a few other early cultivations.

The six specimens of interest are in the herbarium of the descendent of the Colonial Museum, the Museum of New Zealand, with the Maori name, Te Papa.  Carlos Lehnebach, botany curator, and Lara Shepherd, research scientist specializing in DNA sequencing, decided to learn more about the genetics of these six specimens from the 19^th-century BM gift.  When Shepherd got the results of her analysis, she was shocked:  one of the specimens, collected in 1800, had genes of Sophora toromiro, a species endemic to Easter Island, Rapa Nui.  It became extinct in the wild in the 20^th century, though it is cultivated at several botanic gardens.  At first Shepherd couldn’t believe the results, but when she and Lehnebach looked at the specimen, they found that it did in fact have characteristics of the Rapa Nui plant.  But how did it end up growing in Germany in 1800?

The researchers speculate that seeds may have been collected during Captain Cook’s second round-the-world voyage (1772-1775), when the expedition stopped at Rapa Nui.  The botanists on that trip were Johann Reinhold Forster and his son Georg, with the Linnaean pupil Anders Sparrman as their assistant.   They were the first Europeans to collect specimens on the island, and Sparrman was known to have collected seeds.  He may very well have collected them from this plant, since it grew in thickets and was the only native shrub on the island.  If S. toromiro seeds were planted in the late 1770s, then the shrub would have been established enough to yield cuttings in 1800.  In looking for other Sophora specimens, Lehnebach and Shepherd have found one at the herbarium of the Botanic Garden and Botanical Museum Berlin-Dahlem that could be S. toromiro.  It has no collection date, but it is part of Carl Ludwig Willdenow’s (1765-1812) collection, and a large number of Forster specimens were included in it.  Willdenow had one of those bad habits that frustrates later curators:  he removed the old labels and replaced them with his own, often neglecting to transcribe what’s now considered essential information.

Admittedly, there are suppositions holding this story together, but further work, including analysis of chromosomal DNA from the Willdenow specimen, may make the picture clearer.  In any event, this case study presents a good argument for curating specimens that have been moldering in boxes for decades if not centuries.  This situation is not the result of bad management but of overworked curators without time to deal with the substantial work involved in mounting specimens and providing them with up-to-date identifications.  However, this example suggests the exhilaration that can result from the effort.  Though not every find is a jewel, that’s true of cleaning out any attic.  However, one never knows when a first edition book or a valuable art work might come to light.  My favorite statistic at the moment is that when the herbarium at the National Museum of Natural History in Paris was cleared out prior to renovations about 10 years ago, 830,000 unmounted specimens were found.  Most of them have since been mounted by an outside contractor called in for the massive job (Le Bras, 2017).  But the specimens still need to be curated and filed, a job that amounts to organizing a good-sized herbarium.

Reference

Le Bras, G., Pignal, M., Jeanson, M. L., Muller, S., Aupic, C., Carré, B., Flament, G., Gaudeul, M., Gonçalves, C., Invernón, V. R., Jabbour, F., Lerat, E., Lowry, P. P., Offroy, B., Pimparé, E. P., Poncy, O., Rouhan, G., & Haevermans, T. (2017). The French Muséum national d’histoire naturelle vascular plant herbarium collection dataset. Scientific Data, 4(1), 1–16. https://doi.org/10.1038/sdata.2017.16