Friends of the Arboretum Newsletter
Vol. 6, No. 1
Horticulture
Annual Endorsements
By Bob Lyons, Director
 |
"Off the Cuff Comments"
Summaries of Casual Observations from the Field Staff - Summer 2001
First, an introduction........the Annual Trials Area is located like a donut hole within the JCRA. It is one of the most transient garden features we have and generally undergoes a complete turnover twice per year. While you may have enjoyed and studied the plants in our trials in the past, I'm not sure all of our visitors have a full understanding of what goes on there. Like soldier rows, the beds housing these annuals are laid out straight, narrow, and in neat rectangular patterns. We specifically do this for ease of formal evaluation. Each row represents a species or cultivar which a seed company wishes to have evaluated in the Raleigh area; they are likely sending the same plant to other parts of the country for a similar evaluation. In this way, we get a better picture of geographic and climatic effects on new plants marketed by the players in the seed industry. However, I also take the liberty of putting out some "wild cards" each season, that is, some unusual plants I've received from a variety of sources. By the way, our plants are always labeled and I'm indebted to Bernadette Clark for the role she plays in our trials! Performance reports are published twice per year and are available on our Web site at <www.ncsu.edu/jcraulstonarboretum>. I've included a listing of our "Top Ten" (13 since there was a tie) for the summer 2001 season, just in time for making some decisions for your own gardens, but the best thing to do is come and visit regularly and spot the best ones yourself.
Sometimes numbers don't tell the whole story. In the section below, you'll find summarized comments from those we recorded throughout the 2001 growing season......a "between the lines" addition to the actual ratings we make. This list is not exhaustive since not all species received particular comments during the growing season. As in any evaluation program, there are winners and losers, at least for our area. Now you have to make up your own mind! The 2002 summer trials were planted April 25, 2002.
By the way, when you see a rating number referenced below, please know that "5" is our perfect score and "1" is all but dead!
Argyranthemums
From past experience, we have found that the heat of the Raleigh summer is no friend to these plants. Flowering generally declines and disappears completely soon after the spring temperatures warm up permanently; 2001 was no exception. However, of all cultivars examined, 'Maggie' proved the best in returning to a "close to spring" form for floriferousness when cooler weather returned. An interesting note: we found the flowerless, dense clumps of foliage in midsummer to be attractive complements to the garden in spite of their lack of flowers.
Begonias
We are very excited about the growing potential of the 'Dragon Wing' begonia hybrid. It by far exceeded the performance of traditional wax begonias in early July and maintained that pace into September. It is truly a breakthrough in its group with, in our opinion, fabulous potential for landscape use in our climate.....pink or red, makes no difference. Satisfaction is almost guaranteed! By mid-August, another standout was 'Olympia Sprint White'. As usual, the tuberous begonias were the laggards for performance value in this climate, barely eking out any semblance of a respectable display.
Coleus
This year we went "off the boards" and brought in about 30 different sun coleus cultivars from one of our own state breeders/growers Ralph Repp. What a great move! Devoting an entire bed to these wild landscape ornamentals made for a spectacular display. Most grew vigorously and stood out boldly in the beds. What were some of our favorites? Try 'Pineapple Prince', 'Eclipse', 'Florida Sunrise', 'Marie', 'Inky Pink', and the strangely tight and linear 'Dragon's Claw'. The last one has an erect stature with narrow, fluted foliage that is a deep purplish red.....neat and unusual.
Cosmos
I really want to like Cosmos 'Cosmic Orange', but it is doing its best to deny me that pleasure! The early and late season averages for this cultivar were poor, leaving it with a dismal overall rating for the season. Fast to flower and fast to seed seem to characterize this cultivar, barely giving us a chance to enjoy its brilliant flowers and short stature.
Durantas
We placed this fascinating foliage-based plant out in a long border and did it ever attract attention. Its lovely green and cream leaves accented other garden colors, enhancing their visibility. Duranta erecta 'Golden Edge' is easy to propagate from cuttings and freely branches after pinching at planting. We like it despite its occasionally thorny stems!
Geraniums
The Raleigh summer can be tough on geraniums. Our plants were much improved this year, given the renewed attention we paid to deadheading and the assistance provided by Mother Nature's more agreeable weather. Once again, the 'Fantasia' series surfaced over others, with all season averages from 4.1 to 4.4.....respectable indeed! If I had to mention some "runners up," I would include, 'Designer Hot Coral', 'Galleria Sunrise Improved', 'Maverick Light Salmon', and 'Maverick Pink'.
New Guinea Impatiens
Our New Guinea impatiens jumped to the forefront early in the season. By July 3, my personal notes indicated the 'Sonic' series to be real standouts. By the middle of August, we noted the seed-derived cultivars inferior to those that are vegetatively reproduced....generally speaking, the vegetatively propagated cultivars are more interesting. We are still raving about the cultivar 'Celebrette Light Coral'. This year we placed it in a long border where it received much more sun than we'd normally be comfortable with. It shined! Strong and diverse foliage colors, excellent flower display, and a uniformly mounded habit contributed to another excellent year for this cultivar. I recommend it highly!
Petunias
No surprise to anyone, 'Tidal Wave Silver' was a true standout in color and form. We heartily endorse this cultivar for its strong flowering ability and landscape coverage. One big surprise to us was the appearance of a new contender for 'Purple Wave'.....we noticed by midsummer that 'Trailing Purple' might just be the one to dethrone 'Purple Wave'. The numbers proved our visual observations right as the latter scored a Late Season Average of 4.6 and 'Purple Wave' came in at 4.1....we'll keep an eye on this rivalry! Other noteworthy cultivars were 'Ramblin Peach Glo', 'Misty Lilac Wave', and 'Surfinia Giant Purple'. And for the historical record.....I remember when the 'Fantasy' series was released and the initial show was great. Unfortunately, it had a tendency to fade away, even earlier than other cultivars......same thing is still happening.
Portulacas
Oh, my, were the Yubies great or what? It was easy to overlook the somewhat bothersome behavior of afternoon flower closure when the colors were so electric. Strong growth throughout the season, prolific flower production, and high ornamental value were the obvious keys to the notoriety of this cultivar series. We hope these become popular and widely used....stop worrying about getting only a half day out of them. Their outstanding display makes up for their abbreviated show.
Rudbeckias
You don't have to ask, this genus is one of my personal favorites! It is no surprise that I brought in a somewhat new cultivar to look at, 'Chim Chiminee', that was receiving a lot of attention in catalogs. Unfortunately, it didn't live up to my expectations. I'm delighted to see this native North American species used more and more but this cultivar seems to have been released prematurely. The plants were hardly uniform in almost every respect. Colors were wildly variable, flower types ranged from the familiar flat-rayed and wide to the advertised narrow and almost tubular in appearance. I'm all for mixes but this batch showed way too much to be acceptable....send it back to the selection fields and come back later!
Salvias
By August 15, our Salvia splendens were declining fast. This was a disappointment, given that we employed judicious deadheading this year.
Verbenas
An interesting phenomenon popped up when comparing the entries here. The first half of the season accolades went to the 'Tapien' cultivars with their rating of 4.4. By the end of the season, performance flip-flopped when the 'Aztec' series jumped ahead. Bottom line, both are great series and represent the true stars of the genus. I'm afraid these ground cover types are all but knocking their upright cousins out of the competition for landscape performance.
Violas
It appears that violas are still better grown and marketed for winter color in the Raleigh area so far.....their summer performance was indifferent at best, often bordering on completely unacceptable.
Zinnias
Hands down, the 'Profusion' zinnias looked excellent....again. I think this is a real breakthrough in zinnia breeding. To really put them to the test, we placed them immediately next to some traditional zinnias, which surely got powdery mildew, but the Profusions remained clean and sharp. Our periodic deadheading helped maintain their appearance, too. Highly recommended. Bring on more colors!
Odds & Ends
 |
This year, some exceptional standouts included several vegetatively propagated plants. Saccharum officinarum 'Pele's Smoke' was notable and recommended. It's tight, erect stature, dusty purple color, controlled growth rate, and bold foliage made for a lovely specimen plant in the back border. It reached 6-8' tall easily but had strength and durability unlike other tall, grass-like ornamentals. Pennisetum setaceum 'Eaton Canyon' is a dwarf form of the very popular P. setaceum 'Rubrum'. 'Eaton Canyon' is about half the height and a nice alternative but it just didn't flower as much as its cousin. It also tended to be less full and dense....but we still liked it.
The Top Ten
This list shows the species/cultivars with the top 10 All Season Averages....since there were ties, the top 13 selections are listed. The plants with the very best scores are listed first, representing our best performers for the whole summer 2001 season!
- Petunia 'Tidal Wave Hot Pink' - 4.9
- Petunia 'Tidal Wave Silver' - 4.7
- Petunia 'Ruffle Pink' - 4.7
- Impatiens (Double) 'Tioga Hot Pink'- 4.7
- Vinca '01BP19' - 4.7
- Impatiens (Trailing) 'Fanfare Fuchsia' - 4.7
- Vinca 'Blue Pearl' - 4.6
- Portulaca 'Yubi Summer Joy Deep Rose' - 4.6
- Petunia 'Double Wave Pink' - 4.6
- New Guinea Impatiens 'Super Sonic Scarlet' - 4.6
- New Guinea Impatiens 'Celebration Cherry Red' - 4.6
- Impatiens (Trailing) 'Fanfare Lavender' - 4.6
- Petunia 'Wave Misty Lilac' - 4.6
"Hats Off" for Redbuds
By Todd Lasseigne, Assistant Director
 |
Back during the summer of 2000, in preparation for the upcoming demolition phase of the West Arboretum at the JCRA, Denny Werner, Ph.D., (NCSU Professor of Horticulture) mentioned to me the idea of having the Cercis (redbud) collection budded by a nurseryman renowned for his ability to graft redbuds, Harald Neubauer of Hidden Hollow Nursery in Belvidere, TN. Although Mitzi Hole and I had already come up with several ideas on how to "save" the Cercis collection, I was eager to have as much redundancy built in as possible. (For those who do not remember, the JCRA holds the largest collection of Cercis taxa of any arboretum in the world.) Mitzi had propagated the entire collection from softwood cuttings back in the spring of 2000, and although some had not yet rooted, the results looked highly promising. We also had planned on transplanting some of the smaller plants directly to new locations that would be unaffected by the construction of the Ruby C. McSwain Education Center. This would still leave several Cercis taxa unaccounted for, should the cuttings not root. Therefore, I told Denny that I would be happy for him to contact Harald and see if he would be interested in working with us to preserve our collection. Of course, we would offer any additional budwood that he might desire for his own uses. The budwood was sent to Harald in August 2000.
Jumping forward to January 2002, Denny and I traveled to Belvidere to pick up our plants - some for Denny's Cercis breeding program, and the remainder for the JCRA Cercis collection. Both Harald and his son Alex Neubauer greeted us and showed off the prized plants. Virtually all of the 20 or so taxa had been budded at nearly 100% success! Most of the plants had rocketed to 8-10' tall, beautiful plants. After loading our huge bundles of Cercis, we were off, traveling back to NC. The JC Raulston Arboretum owes a special thanks to Harald for helping us preserve this important collection. Kudos on a job well done!
Sweet Potatoes for the Eyes
By Bob Lyons, Director
|
Stay tuned for the new 'Sweet Caroline' series of ornamental sweet potatoes! Named specifically for their individual colors, these new releases are patent pending and represent the combined efforts of the NCSU sweet potato breeding team (Craig Yencho and Ken Pecota), Bodger Botanicals, and the JCRA. Ornamental sweet potatoes (Ipomoea batatas) are one of the hottest groups of landscape plant materials being used today. Perhaps best known by the cultivars 'Blackie', 'Sulfur' or 'Marguerite', and 'Pink Frost' or 'Tricolor', these plants have quickly dominated the tender perennial groundcover market. Just look around and you'll see them somewhere for sure.
However, recognizing that they've got some drawbacks, like very rapid growth and large tuber size for container use, we looked for improved hybrids which have a more dense, controlled habit and reduced tuber size. Of course, it wouldn't hurt to get a new color in there too! We believe that 'Sweet Caroline Bright Green', 'Sweet Caroline Bronze', 'Sweet Caroline Green', and 'Sweet Caroline Purple' all possess more desirable features suitable to both landscape use and container displays. 'Sweet Caroline Bronze' is particularly unique with its brassy, coppery foliage and deeper colored venation.....a color not previously available in this species.
All four cultivars have been released for retail sales in 2002 but early signs of their popularity may create a short supply fast. We are very excited to partner with the NCSU sweet potato breeders and Bodger Botanicals to bring you these improved ornamental sweet potatoes! They have already been featured in Fine Gardening and as the front cover article in NC Cooperative Extension's Successful Gardener.
Raulston Allspice
By Nancy Doubrava, Interpretive Specialist
 |
This exciting, new hybrid from the JC Raulston Arboretum is celebrating its first spring with a new botanical name, xSinocalycalycanthus raulstonii 'Hartlage Wine', and common name, Raulston allspice. This unique intergeneric hybrid is the first successful cross between Calycanthus floridus, our native sweetshrub or Carolina allspice, and Sinocalycanthus chinensis, its rare Chinese counterpart.
The creation of the new genus, xSinocalycalycanthus, has an intriguing story. It all began within a few years following the first flowering of the parent, S. chinensis on the North American continent. Sinocalycanthus chinensis was first discovered in eastern China in Zhejiang Province in 1963. It was distributed from Shanghai Botanical Garden to the University of British Columbia (UBC) Botanical Garden, where it bloomed in 1984. Cuttings were obtained by J. C. Raulston, Ph.D., Director of the NCSU Arboretum from Gerald Straley, Ph.D., then curator of the Asian Collection at UBC Botanical Garden. By 1991, the plant at the NCSU Arboretum was thriving at nearly six feet tall.
One day while observing C. floridus in the Arboretum, it was noticed that although the flowers were very different, the fruits looked similar to those of S. chinensis. Was it possible that these two different genera might be able to be successfully crossed? Richard Hartlage, who was an undergraduate in Horticultural Science at NCSU working at the Arboretum, was asked to take on the project.
In 1991, under the direction of J. C. Raulston, Richard performed a series of reciprocal crosses between the two parents. Using S. chinensis as the female parent and C. floridus as the male, one seedpod was successfully produced with six seeds inside. After stratification (cold treatment) all of the seeds germinated readily. As the seedlings grew, only four survived, which were eventually transferred to field plots.
The four remaining plants continued to grow. It was soon realized that one of the plants had leaves with characteristics intermediate between the two parents. This was the first clue that the plant might be a new hybrid. Five more long years passed before this one amazing plant bloomed for the first time in the spring of 1996, with its unique wine-red flowers, thus confirming it was truly a new intergeneric hybrid.
In July 2001, a scientific paper published in HortScience (authors: Todd Lasseigne, Paul Fantz, J. C. Raulston, and Gerald Straley) officially validated the name as xSinocalycalycanthus raulstonii 'Hartlage Wine'. Following rules of botanical nomenclature, the new genus name was made from the first half of the female parent generic name and the second half of the male parent generic name, creating the tongue twister, xSinocalycalycanthus. The "x" that precedes the new genus designates the intergeneric cross. The hybrid species name, "raulstonii," was given in honor of J. C. Raulston who directed the successful hybridization. The cultivar name, 'Hartlage Wine' was given in honor of Richard Hartlage's contribution to the project. 'Hartlage Wine' refers to any plants propagated and subsequently distributed from the original clone growing at the JC Raulston Arboretum.
Raulston allspice is a great choice for woodland to moderately sunny gardens. This robust, deciduous shrub grows best in part shade. You can also grow it in full sun if ample moisture is provided. In mid-spring, look for its absolutely beautiful, unique, 3-4' wide, maroon, wine-red flowers, each gently splashed with white in the center. This medium to large deciduous shrub has bold, medium-green foliage and subdued yellow fall color.
Currently, Raulston allspice is in the marketing phase as a JC Raulston Arboretum Selection™. Look for it to become available from commercial growers this year or next. Tom Ranney, Ph.D., at the Mountain Horticulture Crops Research and Extension Center in Fletcher, NC, is continuing more hybridization work, including crosses with the western sweetshrub, C. occidentalis, a native of the Pacific Northwest.
Journey to the Nation of Georgia
Part 1
By Todd Lasseigne, Assistant Director
It all started with an e-mail
I received on February 21, 2001 from my good friend, Tomasz Anisko,
Ph.D., Curator at Longwood Gardens. The subject heading for the e-mail simply
read "Caucasus," and when I saw it, I knew that I was in trouble.
Trouble, you ask? Yes, trouble! Having only been employed for six
weeks at that point in time as the new JCRA Assistant Director, I knew before
reading the e-mail that Tomasz was asking me to join him on an expedition.
Furthermore, I knew that I would have to be able to justify, as well as locate
funds for, a trip of this magnitude. I was already in the midst of planning
a trip to Japan to speak to the Japanese Nursery Association (Saitama City
Branch)
in early June 2001, and this trip to the Caucasus was to follow very closely
on the heels of my Japan trip. Clearly, Bob Lyons would
have my head on a platter as soon as I mentioned this to him. Indeed,
on opening Tomasz's e-mail, I found out that he was proposing that I join him
and several other participants on a month-long expedition to explore
the botanical riches of the nation of Georgia. A month, eh?
Wow! This would take quite a bit of convincing, I knew.
Well, the fates must have been with me, because 1) the trip to Japan (subject of a future article) was secured financially through the generous support of Mike Ishii (Ishii Plants, Saitama City, Japan); and 2) I found out that Robert Wright, Ph.D., of Virginia Tech University in Blacksburg, VA (a.k.a. Bob's former boss) was to participate on the Georgia expedition also. With these two items securely in hand, I was able to secure permission to join Tomasz on the Georgia expedition. Through Bob's help, the JCRA was then able to secure generous financial support of this expedition from several sources, including the North Carolina Association of Nurserymen (NCAN), Bobby Ward of Raleigh [with a corporate match of his gift from Carolina Power and Light (CP&L)], and Chip Callaway of Greensboro. With this, I was all set to go, or kind of. I later found out that 1) arranging a round-the-world flight, especially the leg from Tokyo, Japan to Tbilisi, Georgia, was much more involved than I had first realized; and 2) acquiring a visa for Georgia is not something that one should put off until the last minute.
|
|
|
|
|
|
|
|
|
Some of you are probably asking the obvious question: "What are you talking about? Georgia is only four hours drive from Raleigh, after all." Well, yes, that is true, but this expedition would take me to the "other" Georgia - the Georgia that was formerly part of the U.S.S.R., or the "Republic of Georgia" as it is fashionable in the U.S. to call this nation. Perhaps a few introductory facts, along with the map included on this page, are in order to orient you to this fascinating but poorly known and little studied (from a Western viewpoint), part of the world.
Georgia is an ancient nation dating back to circa 4th Century B.C. During its turbulent history, Georgia has been conquered and reborn time and again, surviving to the present day as an independent nation of strong and proud people. Although historically Georgia comprised a much larger geographical area than present maps indicate, currently the land area of Georgia equals nearly 27,000 square miles. The U.S. state of South Carolina measures just over 30,000 square miles, in comparison. Nearly 5.5 million people call Georgia their home, and of these, about 1.5 million live in the capital city of Tbilisi. South Carolina has a population of 4 million. The U.S. state of Georgia is over twice as large as the nation of Georgia, for those who are in need of such facts.
Georgia is situated in easternmost Europe, at the crossroads between Europe and Asia. It sits between the Black and Caspian Seas, with the Black Sea forming its western boundary. To the north, and forming the border with Russia, run the Greater Caucasus Mountains, the highest mountain range in Europe, with Russia's Mount Elbrus towering to almost 18,500 feet above mean sea level (a.s.l.) as the highest peak. On the southern boundary of Georgia run the Lesser Caucasus Mountains. Turkey, Armenia, and Azerbaijan, respectively, border Georgia to the south from west to east. As Georgia lies between the two Caucasian mountain ranges, this region is often referred to as "the Transcaucasus" or "Transcaucasia." Both the Greater and Lesser Caucasus run roughly northwest to southeast. A transverse range, termed as either the Likhis Mountains or the Imeretian Elevation, connects the two Caucasian main ranges. As a result of not only the diverse meso-scale habitats arising throughout Georgia from such geophysical variability, the Imeretian Elevation also serves to effectively divide the country into two vastly differing regions - eastern and western. In ancient times, eastern Georgia was referred to as the kingdom of Iberia. This half of the country is markedly drier, with rainfall decreasing constantly as one travels eastward toward the border with Azerbaijan. In contrast, the western half of the country is drenched with ample rainfall, in some areas exceeding 100 inches per year. This western half of Georgia was known in historic times as the kingdom of Colchis - the place where Jason and his Argonauts sought the legendary Golden Fleece.
Why the protracted history and geography lesson? This is necessary, as I was to fully realize in my 30-day stay, because the geography and the history and the plants are all interconnected. When one encounters Berberis iberica (a rare endemic species of eastern Georgia) or Rhamnus imeretina (which the Hillier Manual calls "the most outstanding of the buckthorns") or Hedera colchica (the ivy we call "Persian," but not the Georgians, who call it "Colchic"), the plants reveal their geography. One caveat that I must add to this, however, is that "Iberia," which we know refers to the Iberian Peninsula of Europe (comprising Spain and Portugal), is, of course, not the same as the "Iberia" of Georgia. When I had first arrived, I was puzzled myself, imagining plants with disjunct geographic ranges between far eastern and far western Europe. To both my satisfaction and disappointment, I came to learn that two points on the globe use this name, and as such, plants from these two regions can, quite independently, be named "iberica." Thus, Iberis sempervirens, the common candytuft, derives its generic name since it is native in both Spain and Portugal. Berberis iberica, Euphorbia iberica, and Geranium ibericum, however, are native only in Georgia. Confused? Good! This should put you on an equal footing as to my state of knowledge when I entered this unknown country last summer.
Why Georgia, then? Certainly other places around the globe would appear more interesting from the standpoint of introducing new ornamental plants into cultivation for North Carolina gardens, eh? Although you might think that a quick answer of "yes" would suffice, in actuality, you probably should not cast judgment so quickly. In the temperate zone of the Northern Hemisphere, several regions share comparable climates and floras. We can all think of the similarities between our flora in the southeastern U.S. and that of southeastern Asia. To a degree, the Transcaucasian region also contains related elements. Genera such as Staphylea (the bladdernuts), Osmanthus (sweet olive), Ostrya (hophornbeam), Carpinus (hornbeam), and Prunus subgenus Laurocerasus (cherrylaurel), to mention only a few, all have species native in eastern North America, southeast Asia, Europe, and the Transcaucasus. [Eastern North America: Staphylea trifolia, Osmanthus americanus, Ostrya virginiana, Carpinus caroliniana, and Prunus caroliniana. Southeast Asia: Staphylea bumalda and other species, Osmanthus fragrans and many other species, Carpinus japonica and many other species, and Prunus zippeliana and others. Europe: Staphylea pinnata, Osmanthus decorus, Ostrya carpinifolia, Carpinus betulus, and Prunus laurocerasus. Transcaucasia: Staphylea colchica, Osmanthus decorus, Ostrya carpinifolia, Carpinus betulus, and Prunus laurocerasus.] Some plants, such as Zelkova, occur in Europe (Zelkova abelicea), the Transcaucasus (Zelkova carpinifolia), and southeastern Asia (Zelkova serrata, Z. sinica, and Z. schneideriana), but not in the U.S. Thus, I knew before I left Raleigh that I would find species analogs to our southeastern U.S. natives occurring on this trip. Furthermore, I knew that this area of the world had, until recently, been closed off to the West, due to Cold War politics and the Iron Curtain. Basically, Georgia was open, unexplored territory.
Through the initiatives of Tomasz, the essential professional contacts had already been made. Fluent in Russian, Tomasz had written a letter of introduction to Professor Giorgi Nakhutsrashvili, Director of the Georgian Institute of Botany in Tbilisi and a member of the Georgian Academy of Sciences. Professor Nakhutsrashvili had approved our trip and made arrangements for us to be hosted and shown around the country by two highly competent botanists, Maia Akhalkatsi, Ph.D., and Marina Mosulishvili, Ph.D., (both of the Institute of Botany), as well as several other botanical scientists who would meet us at various points on the trip. The agenda had been set, and all the team members had to do was get there.
The primary "target species" for this trip was the Colchic boxwood, Buxus colchica, a "species" of which little germplasm had ever been introduced into Western cultivation. To this end, Tomasz recruited several members of the American Boxwood Society, including Maryland nurseryman Charles Fooks, owner of Woodland Nursery (Salisbury, MD); the husband-and-wife team of Paul and Tatum Saunders, of Saunders Brothers, Inc. (Piney River, VA); Robert Wright, Ph.D., who is actively involved in research assessing physiology of container production of boxwoods in the Horticulture Department at Virginia Tech University; and Fred Spicer, who worked for the Willowwood and Frelinghuysen Arboreta (Morris County, NJ) and who participated in the National Boxwood Trials. (Paul Saunders is the coordinator for this relatively new program that evaluates boxwood taxa throughout the eastern U.S. The JC Raulston Arboretum is a participating institution in this program.) The "boxwood team supreme" (my moniker for the group) was thus assembled. However, since I initially knew little about boxwoods before this trip, I felt out of place at the start of the trip. Our expedition team was set with seven participants, a nice small crew that would allow us to access remote areas of Georgia without the aid of a 40-passenger bus.
Although I had not previously been a boxwood aficionado, I became highly intrigued with this "Colchic" boxwood as soon as we first saw it, which was on our very first outing when we journeyed north from Tbilisi to a nearby small village called Navdaraant Kari on June 9, 2001. Not only was I amazed by the huge diversity in leaf shape, size, and color, but I was also surprised to see how successfully the plants were reproducing. All plants consisted of shrubs that had been hacked back, since cut boughs are used in Georgia for "Palm Sunday" services. The Navdaraant Kari population was located near an ancient church dating back many centuries. In fact, we were told by Maia and Marina that all Buxus colchica populations east of the Likhis Mountains are regarded as consisting solely of naturalized populations that have taken centuries to form reproducing stands. (To the unknowing, you would think that they were truly native.) Evidently, Buxus colchica occurs in a truly "native" state only in the western half of Georgia, in so-called "Colchic forests," named so because of their high proportion of evergreen woody species and overall high diversity. One thing that was immediately clear to Tomasz, Charles, and myself (the only members of the team present at this point) was that "Buxus colchica" was no different than B. sempervirens. Leaf morphology, plant habit, and even the fruits were identical to those of the commonly grown B. sempervirens. However, the habitats in which we found these plants began to show promise for introducing germplasm with entirely different physiological tolerances to environmental stresses.
Later, in Tbilisi in the herbarium of the Institute of Botany, Tomasz sought out and found specimens of yet another species of boxwood, Buxus hyrcanum - the Hyrcanian boxwood, a native of forests occurring near the southwestern and southern coast of the Caspian Sea of northern Iran and southeastern Azerbaijan. Even this boxwood, too, looked exactly like B. sempervirens. Oh, sure, there were some herbarium specimens that had much larger leaves just as we had found in B. colchica, but the variation was so high that if one were to mix up these specimens and place them before even the more astute boxwood expert, they would be virtually impossible to tell apart. At this point, my mind immediately went back to Raleigh, to the JC Raulston Arboretum's boxwood collection, and specifically to our plant labeled as Buxus himalayensis, the Himalayan boxwood. I had thought all along that our plants must be mislabeled, since they appeared exactly as B. sempervirens. One theory does exist that could explain this rather confusing situation, however. That is, in the geologic past, a great sea, the Tethys Sea, once ran from the present-day Gulf of Mexico and Mediterranean Sea all the way to eastern Asia, which was possible before Africa, Arabia, and India were connected to the Eurasian continental plate and when North America was connected to Europe. The Tethyan theory suggests that the modern-day floras of the southeastern U.S., southern Europe, the Transcaucasic belt, including both the Colchic and Hyrcanic regions, and the grand arc of the Himalayas all the way to China and Japan once existed as a contiguous palaeoflora. (This would include remnant related floras of the western U.S. and northeastern Mexico.) This larger flora was later disrupted over the eons when the continents split apart, and as the interior regions of the continents (e.g., Asia and North America, in particular) dried out due to changes in rainfall patterns induced by newly formed mountain ranges (e.g., the Rockies of North America, and the Himalayas). Thus, a once-contiguous species could have been split into several relatively isolated populations; e.g., moving eastward: Buxus sempervirens of southern Europe; B. colchica of the western Black Sea region; B. hyrcanum of the southern Caspian Sea region; and B. himalayensis of Himalayan forests. One could almost draw a line from east to west using these plants. This is just one theory, but it does pose interesting questions for the plant geographer in us.
Thus, with this all in mind, started my expedition to Georgia, an expedition like none I had been on before. From the minute I stepped off the plane at the Tbilisi airport, an early morning with a brisk, cold wind blowing, to the day the expedition team journeyed back cross-country to Tbilisi to fly out the next day, I was enthralled with Georgia -- its history, its people, its beauty, and of course, its plants. Cast aside any preconceived notions you may have of this place, as like our own nation, there is more to Georgia than meets the eye. Join me next issue as I'll discuss some of the many wonderful plants, places, and people that were encountered on this journey around the world.
Previous
Director's
Letter | Arboretum
Trips | Horticulture | Development
| People
Next
Formatted into HTML
by Christopher
Todd Glenn
Programs & Education Coordinator
JC Raulston Arboretum
Department of Horticultural Science
North Carolina State University
Raleigh, NC 27695-7609
© The JC Raulston Arboretum, May 2002