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. Clearly the of the plant more than a decade later. Evidence Amur honeysuckle now naturalized in the of naturalized populations did not begin to United States represents a variety of genotypes, appear until the late 1950s, continuing through although the specific geographical range over the early 1970s. These initial reports were har- which these genotypes were collected is not bingers of the invasion to come. For example, known. The SPI’s introduction effort was suc- Lucy Braun, in her 1961 book on Ohio woody cessful : In 1931, the species was available from plants, noted that the Amur honeysuckle was at least eight commercial nurseries throughout "reported only from Hamilton County, where it the country.9 is becoming abundant in pastures and wood- From the 1960s to 1984, the USDA Soil Con- lands." Thirty-three years later the species was servation Service (SCS; now known as the Natu- reported m thirty-four Ohio counties."l l ral Resource Conservation Service) sponsored a The relative delay between first introduction program to develop improved cultivars of Amur (1897) and widespread escape (1950s) of Amur 7

honeysuckle was to be expected for a plant with tammate crop seed and are thereby dissemi- its life-history traits and mode of introduction. nated quickly. First, it is a long-lived woody plant that does In Europe, Amur honeysuckle has been inten- not produce fruit until it is three to five years sively cultivated longer than in the United old and, therefore, will mcrease slowly com- States, but no naturalization has been reported. pared to an annual plant. Second, during this Fruit production by the species, at least in west- earlier period (1898-1950s) Amur honeysuckle ern Europe, seems to be less regular and abun- was typically used in small quantities in land- dant than in eastern North America. Although scape plantings, so the area of subsequent spread the first report of Amur honeysuckle flowering was for some time more limited than would be in eastern Europe (in St. Petersburg in 1883) the case with annual weeds, which often con- mentioned the "sanguineous" fruit, early west-

Pathways and dates of Amur honeysuckle mtroduction to Europe and North Amenca "SCS" mdicates release of improved cultivars by the U.S. Department of Agnculture Sozl Conservation Service ern European notes included data on flowers m winter and early spring. However, seedling only, or remarked on lack of fruit development. growth in forests is severely curtailed by low Not until approximately two decades after the light conditions, which inhibit production of shrub’s introduction into England were the the long shoots that enable seedlings to reach fruits described in British horticultural litera- better light environments. Even as adults, Amur ture. Even as late as 1934, the merits of the plant honeysuckle shrubs are moderately shade intol- as a fruiting shrub were said to be not well erant and are not likely to replace themselves in known in England, although "in warm seasons shady environments unless past disturbances and on certain soils" fruiting could be abun- create a window of opportumty.’~ dant.’z Western European regions apparently The success of Amur honeysuckle in a wide lack certain environmental conditions shared range of habitats and light conditions has logi- by the eastern United States and eastern Asia, cally led to research on its life-history traits, the where fruit production is heavy. expression of those traits in various environ- ments, and the importance of preadaptation. In in the Invaded Ecology Range its original, eastern Asiatic range, Amur honey- Ecological research on Amur honeysuckle did suckle thrives in frequently disturbed habitats. not begin until the 1980s, after the plant had For example, during 1994, one of us (JOL) found achieved a critical level in local plant commu- Amur honeysuckle growing almost alone in nities.’3 Earlier reports had assumed that Amur low-density, low-elevation woodlands and honeysuckle seeds were dispersed by birds, but floodplain forests in northeastern China. Evolu- it was only in 1983 that proof was found by tion in these habitats would presumably favor collecting seeds from the guts of birds. In 1992 traits commonly found among early succes- a group of researchers found that small mam- sional, colonizing species, such as a high repro- mals also consume seeds of Amur honeysuckle, ductive output, seeds that can be efficiently but their low consumption rates are unlikely to dispersed by birds, flexible morphological and affect seed availability.’a physiological characteristics that enable easy The dominant position of Amur honeysuckle response to changing light conditions, and tis- in both forest understories and open sites sues that are readily replaced when lost or prompted researchers to compare net primary damaged." And indeed, Amur honeysuckle pos- production (or annual biomass accumulation) sesses all these traits. in the two environments. Results from the With these traits in place, genetic changes northern Kentucky region indicated that popu- were not necessary for Amur honeysuckle to lations in open areas were more productive than succeed in the United States; the primary deter- forest populations. Net primary production of mining factors for population spread were prob- dense open-grown thickets (as high as 1,350 ably efficiency of distribution and competitive grams per meter per year) approached that of pressure. Distribution-first through SPI and entire mixed woodland communities, suggest- later through commercial nurseries-was wide- ing that Amur honeysuckle has a large impact spread and efficient; competitive pressures were on carbon and nutrient budgets in open sites, minimal in urban and urban-fringe environ- whereas carbon gain is relatively restricted in ments where long histories of human distur- shaded habitats. In addition, open-grown shrubs bance had created vacant niches and abundant readily resprout and reestablish growth when bare ground.’$ clipped annually, but forest-grown shrubs can- Although much is now known about its bio- not sustain this stress.’s logical relationships within its environment, no Light availability is particularly important for study has yet determined whether local extinc- Amur honeysuckle during the seedling stage. tions of native plants are directly linked to inva- Seeds are released in a nondormant condition, sion by Amur honeysuckle.l9 Nonetheless, in and germination and seedling establishment response to its spread and increasmg importance may occur year-round, with a distinct increase in various plant communities, the Illinois in activity during relatively warm, wet periods Department of Conservation adopted a policy in 9

1989 that made its use unac- ceptable in that state, and many methods have been de- veloped for eliminating this species from natural areas.Zo Lessons for the Future Considering the varied func- tions that scientists envisage for the new cultivars they develop and the differing values that people hold regarding nature preservation, it is not surprising that conflicts arise over resource-management policies. For example, at the same time that the SCS was releasing cultivars of Amur honeysuckle for conservation plantings and horticulturists were recommending it as an ornamental, various botanists were decrying its weedy ten- dencies. Furthermore, Amur honeysuckle and many other nonindigenous plants-crown- This drawmg of Lomcera maaclm first appeared m The Gardeners’ vetch (Coronilla varia), for Chromcle m 1907, accompamed by a descmption attmbutmg the plant’s’s still attraction to "its slender, archmg branches with nearly glabrous, ovate, example-are being planted " acummate leaves and dense clusters of creamy-white flowers. across large areas of land, often o r o o· o o . by managers ol public land, at the same time crop quantity or quality, the impact of a single that other managers of parks and natural areas plant species in a natural community is much are attempting to control these species and more difficult to measure. Furthermore, ecolo- actively pursumg an indigenous-species-only gists may disagree on the important levels of policy. Clearly, the time has come for innova- impact (whether population, community, or tive pohcies and multidisciplinary protocols ecosystem). Still, such studies can be done and that can be used for both nonindigenous plants can be much simplified if management goals already firmly established as components of are prioritized before research is begun. regional floras and potential new introductions A special problem is posed by resource- that could homogenize regional floras even management policies for preserves and other further. natural areas that call for indigenous species Sound science, which should be the basis for only. The origin of these policies can be traced any attempt to remove or control plant species, to the formative years of our national park sys- requires proof that the species is negatively tem, when conservation goals were first estab- affecting management efforts in natural com- lished by scientists and park administrators. munities, whether the goals of those efforts are Underlying the goals set at that time, which to establish presettlement conditions, to pre- generally used pre-Colombian conditions as the serve rare species, to maximize species diver- benchmark, was a concept that envisaged suc- sity, or to maintain patterns of disturbance. cessfully preserved ecological systems as assem- However, unlike the effect of a weed in agricul- blages of native species that were balanced, tural plots, which can be measured m terms of stable, and free of human influence. However, 10

achievement and maintenance of the pre- indigenous species in urban landscapes and sur- Colombian benchmark has become increasingly rounding areas is likely to require the kind of difficult, if not impossible, because the distur- large-scale research that is now mostly limited bances that operated historically in natural to pristine systems. areas have been suppressed or altered and the Finally, careful examination of the life- contexts in which species compete have been history traits of the thousands of plants that changed.21 have been accidentally or intentionally intro- Some researchers have devised a new para- duced, coupled with an analysis of when, where, digm for conservation that recognizes the and if these species have naturalized, would be dynamic nature of all ecological systems.22 a useful exercise. Such an analysis would hkely This paradigm does not call for nonindigenous have some predictive value when new introduc- plants to be eliminated from biological commu- tions are proposed or when new cultivars are mties simply because they were not present in being developed.z’ Attention should focus on the past. Instead, they would be evaluated on seed production and germination, as suggested the basis of their roles in ecological processes. by the case of Amur honeysuckle as well as by a In addition, as ecologists Hobbs and Huen- 1985 survey of other plants that eventually neke rightfully pointed out in 1992, certain became problem weeds and by a rating system management activities that attempt to modify for management of nonindigenous plants estab- ecological processes for the benefit of indig- lished in 1993.26 Species with high and con- enous species, such as prescribed burning to sistent seed output, poorly developed seed stimulate seed germination, may at the same dormancy, rapid germination, and the ability to time facilitate invasion by nonindigenous germinate at low temperatures and low light plants. Resource managers may therefore need may be most likely to spread rapidly across a to choose from a menu of conservation goals; wide range of habitats. Since the proportion of some of these goals may call for inclusion of all introduced horticultural species and culti- nonindigenous species while others call for vars that have naturalized is small (usually their elimination. about one percent) and eventually become com- Increased effort should be devoted to studying ponents of our regional floras, the goal of such a the interactions between indigenous and screening process would not be to drastically nonindigenous species and the functional roles reduce plant introductions but to lessen the risk that nonindigenous species now play in biologi- of future problems. cal communities with long histories of human influence. For example, Schiffman found that Endnotes endangered giant kangaroo rats (Dipodomys 1 Mack 1985. ingens), mdigenous to California grasslands, 2 Tnsel and Gorchov 1994. facilitate colonization and dispersal of non- 3 Swmk and Wilhelm 1994, 474. bare and indigenous plants by creating ground 4 Bean 1973. - dispersmg seeds. Indeed, "eradication of [these] ’ Bretschneider 1898, Herder 1864. exotic plants would probably have a significant 6 Thatcher 1922, 1884a, b, negative impact on populations of this endan- Regel 1884, Anonymous Gardens Kew 1898, Amur to Dippel 1889, Royal Imperial gered species."23 honeysuckle, give Botanic Garden 1887. another achieves its domi- example, greatest ~ Rehder 1903 nance in urban heavily disturbed, landscapes. 8 The impact of the species in these systems Famchild 1938, USDA 1899. is not well understood, but it is possible that 9 Farrington 1931. valuable ecological functions-nutrient reten- ’o Sharp and Belcher 1981, Belcher and Hamer 1982, tion, carbon storage, animal habitat improve- Gaffney and Belcher 1978, Lorenz et al. 1989. ment-are served by Amur honeysuckle in the 11 Kammerer 1939, Braun 1961, Pnngle 1973, Tnsel and absence of indigenous species or when niches Gorchov 1994 are unfilled.24 Assessing the function of non- 12 Anonymous 1934. 111

13 E.g., McClain and Anderson 1990; Yost et al 1991. Gaffney, F. B., and C. R. Belcher 1978. Winter storage of shrubs for Tree 14 Ingold and Craycraft 1983, Williams et al. 1992. timely spring shipping. Planters’ Notes 29: 15-17. ls Whittaker 1975, Luken 1988, Luken and Mattimiro 1991. Harty, F. M. 1993. Biological pollution: how Illinois kicked the exotic habit The control and 16 Luken and Goesslrng 1995, Luken et al. 1995a. impact of mvasme exotic species, ed B. N. I~ Bazzaz 1986, Luken and Mattimiro 1991, Ingold and McKmght. Indianapolis: Indiana Academy of Craycraft 1983, Luken 1988, Luken at al. 1995b. Science, 195-209. 18 E.g, Yost et al. 1991. Herder, F. von. 1864. Plantae Raddeanae monopetalae Bulletm de la Societe Impenale des Natur- 19 Luken See, however, 1990, Tnsel and Gorchov 1994. ahstes de Moscou 37: 190-235. zo Harty 1993, Nyboer 1992. Hiebert, R. D., and J. Stubbendieck. 1993. Handbook for zi Luken 1994, Hobbs and Huenneke 1992. ranking exotic plants for management and control Natural Resources 22 Plckett et al. 1992. Report NPS/ NRMWRO/NRR-03/08. Denver: National 23 Schiffman 1994, 534. Park Service, US Department of the Interior 24 Whelan and Dilger 1992, Woods 1993 Hobbs, R. J., and L. F. Huenneke. 1992 Disturbance, and invasion for zs Reichard and Hamilton 1994, Ruesmk et al. 1995. diversity, implications conservation. Conservation G~ 324- z~ Biology Forcella 1985, Hiebert and Stubbendieck 1993. 339.

Imperial Botanic Garden. 1887. Delectus semmum, quae References Hortus Botamcus Impenahs Petropolitanus Anonymous. 1884a. Lomcera maackll Flomst and promutua commutauone offert St. Peters- Botanic Garden. Pomologist 1884: 157. burg’ Imperial Ingold, J. L , and M 1983 Avian on . 1884b. Lomcera maackm. Gardener’s Chromcle J Craycraft. frugivory 22: 536. honeysuckle (Lomcera) in southwestern Ohio U S A. Ohio Journal of Science 83. 256-258 1934. Lomcera maackm as a fruiting shrub. E. L 1939 of note. Morton Gardener’s Chromcle III 96: 312. Kammerer, Honeysuckles Arboretum Bulletin of Popular Information Bazzaz, F. A. 1986. Life history of colonizing plants: 14: 29-32. some demographic, genetic, and physiological Lorenz, D. W. C. and J. D. Ruffner. 1989. features mvasions G., Sharp, Ecology of biological of Conservation for the Northeast. North Amemca and Hawam, ed H. A. plants Mooney Aid 1154. DC: US and J. A Drake NY: Springer-Verlag. Program Washmgton, Department of Agriculture Soil Conservation Bean, W. E 1973 Trees and Shrubs Hardy m the Bmtish Service. Isles London: John Murray, 611. Luken, J O. 1988 Population structure and biomass Belcher, D R , and D. W Hamer. 1982. Improved allocation of the naturalized shrub Lomcera techmque for harvesting Amur honeysuckle maackm (Rupr.) Maxim. in forest and open seeds. Tree Planters’ Notes 33: 17-19. habitats American Midland Naturahst 119. 258-267. Braun, E. L 1961. The woody plants of Ohio. Columbus, OH: Ohio State Umversity Press. 1990 Forest and pasture communities respond to of exotic Amur Bretschneider, E. 1898. History of European Botan- differently cutting honey- suckle Restoration eJ ical Discoveries m Chma London: S. Low, (Kentucky) Manage- ment Notes Marston. 8 122-123.

--- 1994. m natural areas Natural L. 1889. Handbuch der Laubholzkunde Berhn Valuing plants Dippel, Areas 14: 295-299 Paul Parey. Journal and N Goesshng. 1995 Seedling distribution and Fairchild, D 1938. The world was my garden travels of potential persistence of the exotic shrub a plant explorer NY: Scnbner’s. Lomcera maackm in fragmented forests. Farnngton, E. I. 1931. Ernest H Wilson plant hunter American Midland Naturahst 133: 124-130. with a hst most important introductions of his -- and D. T. Mattimiro 1991. Habitat-specific and where to get them Boston: Stratford. resilience of the invasive shrub Amur Forcella, F. 1985 Fmal distribution is related to rate of honeysuckle (Lomcera maackuJ during spread in alien weeds. Weed Research 25. 181- repeated clipprng. Ecological Apphcations 1: 191. 104-109. 12

---, T. C. Tholemeier, L M Kuddes, and B. A. Schiffman, P. M. 1994. Promotion of exotic weed Kunkel. 1995. Performance, plasticity, and estabhshment of endangered giant kangaroo acclimation potential of the nonindigenous rats (Dipodomys mgens) in a California shrub Lomcera maackm in contrasting light grassland. Biodmersity and Conservation 3: environments. Bulletm of the Ecological 524-537. Amenca 76: 161. Society of Swmk, F., and G. Wilhelm. 1994. Plants of the Chicago ---, T. C Tholemeier, B. A. Kunkel, and L. M. Region. Indianapolis: Indiana Academy of Kuddes. 1995. Branch architecture plasticity of Science, 474. Amur maackll honeysuckle (Lomcera [Rupr.] Thatcher, A. E. 1922. Chinese shrubs at Aldenham. Initial in extreme Herder)~ response light Gardener’s Chromcle III 71: 114-115, 123, 137, environments. Bulletm the Botamcal of Torrey 179, 199, 213. Club 122: 190-195. Trisel, D. E., and D. L. Gorchov. 1994. Regional R. N. 1985. their Mack, Invading plants: potential distribution, ecological impact, and leaf to Studies m contribution population biology. of the invasive shrub Lomcera Plant L phenology Demography John Harper Festschmft, maackil. Bulletm of the Ecological Society of 127-142. ed. J. White. London: Academic Press, America 75: 231. R. 1992 Nyboer, Vegetauon management gmdelme: Whelan, C. J., and M. L. Dilger. 1992. Invasme, exotic bush honeysuckles-Tataman, Morrow’s, Belle, shrubs a paradox for natural area managers? and Amur Lomcera tatamca honey-suckle L., Natural Areas Journal 12: 109-110. L. morrown Gray, L x bella Zabel, and L. maackm [Rupr ] Maxim.) Natural Areas Whittaker, R. H 1975. Commumries and ecosystems Journal 12: 218-219. NY: Macmillan Pickett, S. T. A , V. T Parker, and P. L Fiedler. 1992. The Woods, K. D. 1993. Effects of invasion by Lomcera tatanca L. on herbs and tree in four new paradigm m ecology implications for seedlings conservation biology above the species level New England forests. Amemcan Midland Conservanon biology the theory and practice Naturahst 130: 62-74 ’ nature and , of conservation, preservauon Yost, S. E., S. Antenen, and G Hartvigsen. 1991. The .-~ ~ ed. P. L Fiedler and S. K. management, Jain. vegetation of the Wave Hill [NY] natural area. NY: Chapman and Hall. Bulletm of the Torrey Botamcal Club 118: Pringle, J S 1973 Lomcera maackm (Caprifoliaceae) 312-325. adventme m Ontario. Canadian Field-Natur- ahst 87 54-55. Acknowledgments Regel, E. 1884. Lomcera Maacki Maxim Gartenflora 33: This study was supported by National Science 225-226. Foundation grant DEB 9306217, the National Geographic Society, and a summer fellowship from A. 1903. of the genus Lomcera Annual Rehder, Synopsis Northern For aid we thank the Missoun Botamcal Garden 14 Kentucky University. report of Carol Linda Beth 27-232. Baskin, Jerry Baskin, Kuddes, Merten, Becky Norris, Bruce Parfitt, Floyd Swmk, Don Trisel, Reichard, S. H., and C. W. Hamilton. 1994. Predicting and Charles Williams. Facilities of the Lloyd Library invasive potential of woody plants introduced and the hbrary of the Missouri Botanical Garden to North America. Bulletm of the Ecological were invaluable. This article has been adapted from Society of Amenca 75~ 190. BioScience, Volume 46, Number 1. Royal Gardens Kew 1896. Hand-hst of trees and shrubs grown m arboretum. Part II. Gamopetalae to James O. Luken is an associate professor and John W. London: H M. Monocotyledons Stationery Thieret is a m the of Office. professor Department Biological Sciences at Northern Kentucky University in Highland Ruesmk, J. L., I. M. Parker, M J. Groom, and P. M. Heights. Luken is an ecologist studying the physiological Karelva. 1995. Reducmg the risks of non- ecology of invasive woody plants Thieret is a plant indigenous species introductions. BioScience systematist speciahzmg in the taxonomy of grasses and 45: 465-477 in flonstics.