Seven-Son Flower from Zhejiang: Introducing the Versatile Ornamental Shrub Heptacodium jasminoides Airy Shaw Gary L. Koller This fall, the Arnold Arboretum will begin distributing seedlings and rooted cuttings of a splendid new shrub from China In 1916, Alfred Rehder of the Arnold Arbor- miconioides because, he wrote, "In its habit etum described a new genus of shrub in the and general appearance this plant suggests a pages of Plantae Wilsonianae, the hefty, member of the family of Melastom[at]aceae three-volume "enumeration of the dried plants and on account of the comparatively small collected by Mr. E. H. Wilson during his flowers in terminal panicles it resembles par- expeditions to western China in behalf of the ticularly Miconia. Only close examination," Arnold Arboretum." Dubbed Heptacodium he continued, "showed that this interesting "in allusion to the seven-flowered heads of plant belongs to the Caprifoliaceae." It is the inflorescence" (from the Greek e~za, interesting to note that Wilson collected seven, and xw8e~a, a poppyhead), the genus Magnolia biondii near the same site, but at was assigned to the Caprifoliaceae, the family an elevation of six hundred meters (above two to which Lonicera (the honeysuckles) and thousand feet). Magnolia biondii recently Abelia belong. Translated, the plant’s Chinese was introduced to North America through name means "seven-son flower from Zhe- the efforts of the Arnold Arboretum. jiang." The next reference to the genus Hepta- Wilson collected the plant at Hsing-shan codium did not occur until thirty-three years in western Hupeh (Hubei) province, China later, in 1952, when Henry Kenneth Airy (Collection Number 2232). He made two col- Shaw, a taxonomist at the Royal Botanic Gar- lections of it, one in July and the other in dens, Kew, described "A Second Species of October 1907, from cliffs at nine hundred the Genus Heptacodium Rehd. (Caprifoli- meters (about three thousand feet) above sea aceae)" in the Kew Bulletin. Airy Shaw states level, where it was rare. In examining the that herbarium specimens, Rehder found "that there have lain in the Kew only a single ripe fruit was available for for many years examination," which probably explains why Herbarium two sheets of an undetermined Chinese shrub with opposite trinerved leaves no living plants resulted from that expedi- and a terminal of tion. Rehder named the thyrse superficially jas- plant Heptacodium mme-hke flowers....Havmg previously taken some interest in the Caprifohaceae (Honey- Opposne: A leaf of Heptacodmm ~asmmoides Airy suckle Family), the writer recalled a rare Shaw sho~nnng the tnnerved venation. This and the shrub collected in Hupeh and described by other photographs that accompany this article were Rehder....[R]eference to the isotype pre- taken by the author m the Arnold Arboretum during served at Kew showed that this was clearly the fall of 1985 Professor Zou Shou-qmg kmdly sup- the correct of the plied the calhgrapby which says "Zheyang seven-son generic disposition myste- flower."" rious specimen....The discovery is of some 4 interest, since the original species was noted recalls having avidly and voraciously plucked by Wilson as being very rare, and as far as I the fruits. am aware has not been collected since. The seeds came from a plant originally dug Airy Shaw described the new species, naming up in the Zhejiang Province Preserve, it Heptacodium jasminoides. Since he had approximately five hundred miles south of only dried herbarium specimens, no living Hangzhou. This is the type locality for Hep- material of the new species could be distrib- tacodium jasminoides, and Dudley feels that uted. the original seedlings are as authentic as bot- anists can hope to get at the present time. The seeds to be fresh and The 1980 Sino-American Botanical proved reliable, producing plants at both the Arnold Arbor- Expedition etum (AA 1549-80) and at the National Heptacodium again disappeared from the Arboretum (NA 49226). The National Arbor- view of plant scientists outside China. The etum’s records state that the seed parent was first opportunity Western botanists had to a tall, arching, multistemmed shrub about observe it firsthand did not come until five meters (sixteen and a half feet) tall. recently, when the 1980 Sino-American Dudley reports that seedlings were quickly Botanical Expedition provided seeds and the distributed to the Cary Arboretum of the opportunity to introduce living plants to New York Botanical Garden in Millbrook, North America. The American contingent of New York. I was unable to find that any the Expedition consisted of Stephen A. plants had been introduced to the University Spongberg of the Arnold Arboretum; Theo- of California Botanical Garden at Berkeley. dore R. Dudley of the United States National Thus, it appears that only the three East Arboretum; Bruce Bartholomew of the Uni- Coast gardens were responsible for the orig- versity of California Botanical Garden at inal introduction materials. Berkeley; David E. Boufford, then at the Car- On February 26, 1981, the Arnold Arbor- negie Museum in Pittsburgh (now with the etum obtained a second lot of seeds (AA 403- Arnold Arboretum); and James Luteyn of the 81) through the 1980 Index Seminum (Item New York Botanical Garden. They collabo- 519), circulated by the Hangzhou Botanical rated with a team of Chinese scientists from Garden to botanical institutions throughout various institutions in exploring the native the world. It is quite likely that a number of wild flora. Their travels through China took other gardens received seeds of Heptacodium them to Hangzhou Botanical Garden in jasminoides through this distribution. Hangzhou, Zhejiang province, China ~30° 15’ As of January 1986, the Arnold Arboretum north latitude, 120° 16’ east longitude, at had six plants from the 1980 Expedition. 26.42 meters [about 83 feet] above sea level). They are growing out of doors in the nursery Spongberg and Dudley report that while on and range from two to three meters (about a tour of the Garden on November 1, 1980, six to ten feet) in height. One plant from this they were shown a plant of Heptacodium jas- seed lot appears to be a compact form, for, minoides. Multiple-stemmed and arching, it while it is the same age as the other plants, was growing in full sun. The staff of the it is only seventy-five centimeters (about Garden kindly accommodated the Ameri- thirty inches) tall. It is, however, crowded cans’s request for seeds. Dr. Dudley, who felt into the middle of a row of tightly spaced great excitement at seeing a living plant of seedlings and is therefore subject to intense Heptacodium, a genus he had read about competition. Perhaps, if given more space, while doing research on the Caprifoliaceae, its growth will accelerate to the typical rate. 5 A spray of Heptacodium ~asmmoides. The "opposite tnnerved leaves" and "superficially tasmme-hke flowers" are easily seen in this photograph. Barry R. Yinger, the Curator of Asian fore so limited, it is important that we seek Plants at the National Arboretum, reports additional germplasm directly from wild that the National Arboretum has eleven sources in China. plants from the original collection, which Our first order of business was to get the recently were planted outdoors, in China seeds to germinate. As with most seeds for Valley. In addition, they have one plant (NA which we have no recorded experience, we 54102) that they acquired from Dr. James C. divided the seed lots into a number of treat- Raulston, Department of Horticultural Sci- ment groups. Peter Del Tredici of the Arnold ences, North Carolina State University, Arboretum’s plant-propagation staff reports Raleigh. Dr. Raulston obtained his original that the best germination resulted from cuttings when he was on a field trip to the exposing the seeds to five months of warm Arnold Arboretum in 1983. (This demon- stratification at 65 degrees Fahrenheit in a strates just how fast plants can change hands, moist medium consisting of equal parts of passing from one garden to another, once sand and peat moss, followed by three months they arrive in North America!) At this point of cold stratification at 36 degrees Fahren- it seems that all plants in North America can heit. Five seeds in Lot 1549-80 and six in Lot be traced back to these two seed lots, which 403-81 germinated after this treatment. appear to have a common origin in a single Unfortunately, our records do not indicate parent plant at the Hangzhou Botanical how many seeds were sown in either lot; we Garden. Since the genetic diversity is there- therefore cannot give germination percent- 6 ages. Four additional seedlings resulted from one and nine-tenths centimeters (one-half to alternative treatments. three-quarters inch). The plants have pro- duced multiple stems originating from ground Hardiness level, and the growth thus far is erect and upright, with little side-growth develop- Once we had obtained seedlings, we turned ment. Small branches are square or four- our attention to the question of cold hardi- angled. The thickest stem on any of the ness. Would the of Heptacodium seedlings plants is four and one-half centimeters (one jasminoides at the Arnold Arboretum sur- and three-quarters inches) in diameter at vive outdoors during the winter? We found approximately two and one-half centimeters that they grew rapidly and were large enough (one inch) above the soil level. The stems to be outdoors in rows transplanted regular produce thin bark that peels off in small, within one or two seasons. They have sur- paperlike strips or sheets. During the winter, vived three, perhaps four, winters out of these plants stand out from their neighbors doors.