The Magazine of the Arnold Arboretum VOLUME 78 • NUMBER 3 The Magazine of the Arnold Arboretum VOLUME 78 • NUMBER 3 • 2021 CONTENTS Arnoldia (ISSN 0004–2633; USPS 866–100) 2 Building a Comprehensive Plant Collection is published quarterly by the Arnold Arboretum Jeffrey D. Carstens of Harvard University. Periodicals postage paid at Boston, Massachusetts. 5 A Conservation SOS: Polygonum hickmanii Holly Forbes Annual subscriptions are $20.00 domestic or $25.00 international, payable in U.S. dollars. 7 An Unusual Autumn at the Dana Greenhouses Subscribe and purchase back issues online at Tiffany Enzenbacher https://arboretum.harvard.edu/arnoldia/ or send orders, remittances, change-of-address notices, 10 A Brief History of Juglandaceae and all other subscription-related communica- Jonas Frei tions to Circulation Manager, Arnoldia, Arnold Arboretum, 125 Arborway, Boston, MA 02130- 18 Discovering the Majestic Mai Hing Sam of Laos 3500. Telephone 617.524.1718; fax 617.524.1418; Gretchen C. Coffman e-mail [email protected] 28 Backyard Climate Solutions Arnold Arboretum members receive a subscrip- Edward K. Faison tion to Arnoldia as a membership benefit. To become a member or receive more information, 38 A New Look at Boston Common Trees please call Wendy Krauss at 617.384.5766 or Kelsey Allen and W. Wyatt Oswald email [email protected] 42 Case of the Anthropocene Postmaster: Send address changes to Jonathan Damery Arnoldia Circulation Manager 44 Planting Edo: Pinus thunbergii The Arnold Arboretum Rachel Saunders 125 Arborway Boston, MA 02130–3500 Front and back cover: Jonas Frei’s collection of walnut family fruits includes a disc-shaped wheel wingnut (Cyc- Jonathan Damery, Editor locarya paliurus, back cover) among other more familiar- David Hakas, Editorial Intern Andy Winther, Designer looking species. Photo by Jonas Frei. Inside front cover: Glyptostrobus pensilis is the only living Editorial Committee member of a genus that was once widespread throughout Anthony S. Aiello the Northern Hemisphere. The illustration shows a Glypto- Peter Del Tredici strobus fossil collected near Reading, England. From Gard- Michael S. Dosmann ner, J. S. 1886. British Eocene Flora (vol. 2, part 3). London: William (Ned) Friedman Palaeontographical Society. Biodiversity Heritage Library. Jon Hetman Julie Moir Messervy Inside back cover: The precision of Itoˉ Jakuchuˉ’s observa- Jonathan Shaw tions is evident in Old Pine, an ink painting in which he fluidly captures the essence of a Japanese black pine (Pinus thunbergii). Painting: Harvard Art Museums, promised gift Copyright © 2021. The President and Fellows of Harvard College of Robert S. and Betsy G. Feinberg, © photography: John Tsantes and Neil Greentree © Robert Feinberg (TL42147.7). Photograph of Japanese black pine (11371*M) at Arnold Arboretum by Jonathan Damery. Publication note: Volume 78 will comprise six issues published on the current quarterly schedule. Volume 79 will begin with the first issue published in 2022 and will include four issues. CARSTENS, J. D. 2021. BUILDING A COMPREHENSIVE PLANT COLLECTION. ARNOLDIA, 78(3): 2–4 Building a Comprehensive Plant Collection Jeffrey D. Carstens uilding a germplasm collection can take McCoy connected me with Marty Silver, a years or, more realistically, even multiple park ranger at Warriors’ Path State Park, who Bcareers to assemble. The United States graciously volunteered to help. Silver stated National Plant Germplasm System has nine- he had “limited botanical skills” and was sim- teen stations around the country, and the goal ply an “interested amateur botanist spending is to acquire, conserve, evaluate, and distribute spare time in the field in various wild places genetically diverse plant material. As a gene- in Tennessee.” To ensure initial success, we bank curator at the North Central Regional selected Monarda didyma as the target from Plant Introduction Station in Ames, Iowa, I’m eastern Tennessee, since we had no holdings responsible for managing collections of woody of the species from the region. The species also plants like ashes (Fraxinus) and chokeberries displays very conspicuous red flowers from (Aronia), and also herbaceous plants. The col- July through August and is somewhat ubiqui- lections arise from plant exploration by staff tous in the target area. This would make the members (I typically make at least five col- plants relatively easy to locate. By the end of lection trips per year), through exchange with August 2018, Silver had documented several other genebanks or public gardens, or by spe- flowering patches of M. didyma, and that fall, cific arrangements between a curator and an he returned and successfully collected seed independent collector. The latter became more (accession Ames 34356). Despite living approx- important than ever in 2020, as the coronavirus imately an hour away from the sampling site, pandemic restrictions prevented normal travel. Silver conducted this travel and exploration on One of our most notable collections from a volunteer basis. this unusual season occurred in the mountains As Silver and I communicated after the 2018 of northeastern Tennessee. The story, however, collection, he drew my attention to a very began in June of 2018, when I sent an email to thorough floristic survey of the nearby Rocky Roger McCoy, the director of the Tennessee Fork Tract, written by Foster Levy and Elaine Division of Natural Areas, looking for con- Walker, published in 2016. Silver connected me tacts in eastern Tennessee who might be able with Levy, who brought our attention to several and willing to collect native Monarda species. Monarda specimens from the area that were Monarda, or the bee balms, is a group of her- labeled M. × media, a taxon that was missing baceous plants native to North America and within our germplasm collection. We desig- Mexico and is represented by approximately nated this hybrid as our next target. eighteen species. Our Monarda germplasm Monarda × media is of potential interest for collection in Ames currently includes four- development as an ornamental landscape plant. teen species, represented by 164 accessions. Moreover, when I reviewed the published litera- In the last couple of years, we’ve acquired ture and herbarium specimens, I found a curious interesting samples, including three species backstory for the taxon, suggesting that well- that were first described by botanists within documented wild collections could also support the past decade: M. luteola, found in north- taxonomic research. The taxon was described eastern Texas and southwestern Arkansas; M. over two hundred years ago, in 1809, by the austroappalachiana, endemic to the Southern German botanist Carl Ludwig Willdenow, who Appalachians; and M. brevis, a dwarf, early- published the name without the multiplication flowering species found in West Virginia and symbol. The symbol is used to indicate plants historically in Virginia. of hybrid origin, although it is not required in Facing page: Collaboration is key for developing a plant germplasm collection. A recent seed collection of Monarda × media in northeastern Tennessee is a case in point. PLANT PHOTOS BY MARTY SILVER; SEEDS BY ASHLEY SONNER, USDA ARS NCRPIS Monarda 3 4 Arnoldia 78/3 • February 2021 a taxonomic name nor does authorship change the field as an opportunity to be completely in the event a name is later recognized as a distanced while regaining a sense of normalcy. hybrid. While Willdenow’s description does Using Levy’s herbarium vouchers, we identi- not suggest that he recognized this taxon as a fied a total of three potential sites, but since hybrid, he nonetheless noted an affinity to M. the specimens were described from a broad geo- fistulosa, commonly known as wild bergamot. graphic area, their relocation was going to be By 1901, Merritt Fernald, a botanist at Harvard, challenging. A few weeks later, Silver reported described observing numerous intermediate findingMonarda × media while on a hike on his forms of M. media, making separation from day off. His hike to get to these populations was M. fistulosa difficult. three and a half miles (one way) with an eleva- Currently, Monarda × media is recognized tion climb of over two thousand feet. He took as a variable group of plants with intermedi- notes, GPS coordinates, and photos. Making ate characteristics of M. didyma and either the hike once again in the fall, Silver relocated M. fistulosa or M. clinopodia or both. These the five previously flagged flowering patches, numerous intermediate forms may stem from but one patch had been completely destroyed the various hybrid combinations, and thus, the and another patch was nearly decimated due name M. × media should ultimately be assigned to human disturbance. He collected seeds from to a specific combination (for instance, M. the available patches and then shipped them didyma crossed with M. clinopodia), with new to Iowa. I assigned them an accession num- names given to each of the others. Surprisingly, ber (Ames 35579) and deposited them into the Willdenow did not designate a type herbarium repository’s freezer, which maintains the seeds specimen, which could make it more difficult at 0°F (-18°C). This collection will be periodi- to determine which combination should, in cally monitored for viability, and when ger- fact, retain the original name. mination falls below a critical level, it will be To correctly sample true-to-type specimens regenerated using controlled pollination tech- of Monarda × media in nature, Silver would niques ensuring the preservation of the genetic need to mark populations in bloom, since M. profile for the future. Since Silver sampled each clinopodia—a white-flowered species—and clonal patch separately along with appropri- M. didyma are often found nearby; sometimes ate plant descriptions, the collections will be they are even intermixed with M. × media. This important resources for future research (includ- raises an interesting question about whether ing ecogeographic and phylogenetic studies). M. × media plants are stable in nature or The collections might also be useful for select- ing superior genotypes for the nursery industry.