Amur Honeysuckle, Its Fall from Grace james O. Luken and john W. Thieret This account of the history and biology of Lonicera maackia explains how and why the plant became so wildly successful as an "exotic invasive." Scientists throughout the world are concerned by many resource managers as an undesirable about the apparent homogenization of regional element in parks, natural areas, and preserves: floras being caused by invasive, nonindigenous "It would be difficult to exaggerate the weedy plant species. A new term for this process, potential of this shrub."3 This perception, how- biological pollution, has come into use, and ever, is not shared by gardeners and horticultur- removal of nonindigenous plants to protect ists-W. J. Bean wrote that "[I]t is one of the native species and to maintain the integrity most beautiful of bush honeysuckles"4-and its of communities is now a common practice garden value has encouraged widespread intro- in many parks and nature reserves. However, duction. Such varied and sometimes opposing human activity is an important determinant of values must be considered along with ecological the eventual rate and extent of diffusion of a data as future management policies for non- non-native species into a new geographic range, indigenous species are debated. whether the plant was introduced intentionally Our case study will address the following or accidentally.’ Therefore, as the time, effort, questions: How and why was Amur honey~ and resources committed to managing non- suckle intentionally introduced into cultivation indigenous plants increases, a need is emerging in the United States? What life-history traits of for greater understanding of the naturalization the species contribute to present-day valuations process on the part of people who may either of the species, both positive and negative? To facilitate or limit plant invasions, especially what extent are these differing perceptions since human influences can often be modified reflected in management policies? by effective policy decisions. The In this article we trace the almost 150-year- Species long involvement of Western plant scientists Amur honeysuckle (also known as bush honey- with the eastern Asiatic shrub Amur honey- suckle, tree honeysuckle, or Maack’s honey- suckle-Lonicera maackii, a member of the suckle) is an upright, multistemmed, deciduous Caprifoliaceae. The story of Amur honeysuckle shrub that can achieve heights of twenty parallels that of various other Eurasian decidu- feet. The leaves are dark green, with a variety ous shrubs-for instance, Russian olive (Elae- of shapes ranging from lance heads to broad agnus angustifolia), Tatarian honeysuckle ellipses that taper to a slender point. Amur (Lonicera tatarica), and buckthorn (Rhamnus honeysuckle leaves are particularly noticeable cathartica)-that were introduced for their in early spring as they open well before those floral, fruit, and foliage displays but eventually of other plants. Likewise, in autumn this hon- became troublesome. eysuckle holds its leaves later than its neighbor- Less than a century after its deliberate intro- ing plants. duction into North America, Amur honey- In its native range-central and northeastern suckle is growing and reproducing in at least China, the Amur and Ussuri river valleys twenty-four states of the eastern United States of Korea, and isolated parts of Japan-Amur and in Ontario, Canada.2 The plant is perceived honeysuckle is commonly found on floodplains The bmght red bernes of Amur honeysuckle remam on the shrub until January unless removed by bmds. 4 Native and mvaded ranges of Amur honeysuckle Isolated occurrences m Japan are not shown and in open woodlands. In the invaded areas explorer, Robert Fortune, probably from a Chi- of the eastern United States and Ontario, it nese garden; but it was specimens collected near occurs mostly in urban or urban-fringe land- the Amur River in 1855 by the Russian plant scapes, where it occupies open sites, forest explorer Richard Maack that served as the basis edges, and the interiors of forest patches. Its for eventual description of the species.s reproductive characteristics give Amur hon- Beginning in the late 1800s, European and eysuckle its greatest appeal. It consistently American plant hunters who exported living produces an early spring profusion of white plant materials from Asia played a pivotal role flowers that turn dull yellow with age. Fruit in introducing Amur honeysuckle to Western set can be heavy, and the bright red berries horticulture. A German horticulturist, E. Regel, remain on the shrubs until January unless reported the first successful cultivation of Amur removed by birds. honeysuckle outside its native range, at the Imperial Botanical Garden in St. Petersburg in Amur in the West Introducing Honeysuckle 1883, using propagules sent from Manchuria in Anecdotal evidence suggests that Amur honey- 1880. Regel’s 1884 report was soon translated suckle was cultivated in gardens of China long into English and used as the basis for writings before European plant hunters discovered the on Amur honeysuckle published in Great Brit- species. In the nineteenth century, these gar- ain. It was being cultivated in Germany by 1889 dens offered many new species to the landed and at the Royal Botanic Gardens at Kew by aristocrats of the West who had grown weary of 1896. The original plants in western Europe standard cultivars and were eager for novelties. probably came from St. Petersburg, which was The first herbarium specimen of Amur honey- distributing seeds of Amur honeysuckle as early suckle was collected in 1843 by an English plant as 1887.~ 5 The St. Petersburg Garden was also the source of the first seeds recorded in the United States, which arrived at the Arnold Arboretum in 1897. The second record of introduction-sent to the New York Botanical Garden by the United States Department of Agriculture- followed by only a year. However, the earliest known report of Amur honey- suckle cultivation in North America is in the archives of the Dominion Arbo- retum m Ottawa, indicating that plants of Amur honeysuckle were received there in 1896, from Spaeth Nurseries in Germany.’ Major botanical gardens, commercial nurseries, and horticultural societies of that time worked together to inform private gardeners about new introduc- tions. During the late 1800s and early 1900s, botanical gardens in Europe main- tained active seed-exchange programs and annually published inventories of available seeds. In 1907 and 1915 the plant received awards of merit from the Royal Horticultural Society. Since 1900, Basal stems of Amur honeysuckle. it has been described frequently in horti- cultural literature published in Belgium, France, Germany, Great Britain, and the United States. This table gives the year that European botamcal gardens first listed Amur honey- suckle m their mventomes of seeds available An Amur honeysuckle grown m an open envmonment. through their exchange programs. Disseminating Amur Honeysuckle in honeysuckle. These plants were intended for the United States the traditional SCS functions-soil stabilization and reclamation-as well as habitat In an effort to obtain potentially valuable, cold- improving resistant varieties of alfalfa, the USDA dis- for birds and serving as ornamental landscape patched an agricultural explorer, Niels E. plantings. Five introductions occurred this Hansen, to Russia in 1897. Hansen unilaterally during expanded his charge and began shipping seeds of period. From plants already naturalized in vari- ous of the United were many other species to Washington, D.C. His parts States, specimens selected for more abundant fruit seed packets began arriving at the same time production, and then cultivated at that a new unit within the USDA, the Section of propagated vegetatively, centers for materials around the Foreign Seed and Plant Introduction (SPI), was plant country. being funded and organized. Amur honeysuckle Occasionally the SCS would make seedlings seeds gathered in Russia by Hansen and received available to other government agencies involved in reclamation work. Amur in 1897 were among the first seeds catalogued Although honey- by the SPLB suckle did not prove particularly useful for soil The SPI facility in Washington, D.C., served stabilization, the ease of harvesting its seeds and the of seed- as a center for distributing seeds to commercial mechanically high survivability after cold facilitated its distribu- growers, botanical gardens, and private indi- lings storage viduals throughout the United States. Seed tion and establishment in large reclamation In the distributions were designated as "Plant Intro- projects. addition, consistently high flower and fruit of Amur duction Experiments," and it was assumed that production honey- recipients would report back to the SPI regard- suckle proved well suited for wildlife habitat More seeds ing their success or failure with the seeds. improvement. commonly, however, Indeed, the 1898 introduction of Amur honey- were made available on request to commercial suckle to the New York Botanical Garden was a nurseries and the resultmg plants were sold to Plant Introduction Experiment. The results of private individuals. The most successful of is still recom- this introduction are not known, but almost cer- these cultivars, ’Rem-Red’, mended the SCS the and is tainly it was successful, considering the ease by (now NRCS) available.’° with which the species can be propagated. commercially The SPI’s records indicate that its facility of the Amur received at least seven shipments of Amur hon- Escape Honeysuckle eysuckle between 1898 and 1927. (This repre- The first record of Amur honeysuckle’s ten- sents a minimal number of shipments because dency to spread beyond the point of initial imported honeysuckles were often not identi- planting is found in the archives of the Morton fied as to species.) These importations origi- Arboretum, near Chicago, and dates from the nated at botanical gardens m Great Britain or mid-1920s. In spite of this early warning, the were collected in Manchuria by agricultural Morton Arboretum was still toutmg the virtues explorers working for the USDA.