It was in the late summer of 1901, while exploring the mountains northwest of Ichang, Hubei, China, that Ernest Henry Wilson encountered a shrub which would become one of his favorite introductions: Kolkwitzia amabilis. At the time, he wasn’t even quite sure what it was—his notes for collection #1007 simply state that the unnamed plant was 5 feet (1.5 meters) tall, had been free-flowering, with possibly red blooms, and had spinose fruits. The seeds were sent to Veitch Nursery in England where they germinated and grew. In November 1907, plants (labeled as Abelia sp.) were sent to the Arnold Arboretum—the species’ first introduction to North America.
Shrubs (now under the correct moniker Kolkwitzia) flowered at the Arboretum for the first time in June 1915. Their early-summer displays of pink blossoms, profusely borne on arching branches, so impressed Wilson and others that it was christened beautybush. Thereafter, in early to mid June, the Arboretum’s Bulletin of Popular Information routinely included a glowing snippet about the blooming Kolkwitzia, how big they were getting, and which specimen in the Arboretum was faring best. In fact, the species’ merits were lauded to such an extent that in 1927 Wilson noted that the original plant on Bussey Hill had “been much mutilated for propagation purposes, and from it, either by seeds or cuttings, has originated the whole stock of this plant in America.”
Not everybody agreed with Wilson’s endorsement, however, with some even suggesting that plants were not as gorgeous in flower as claimed, or that the plants didn’t flower at all. His dander up, Wilson sought to set the record straight on several occasions. His statement on June 7, 1930, (a few months before his untimely death) sums it up: “There is a foolish rumor abroad that this plant when raised from seed does not blossom. The story is ridiculous since the original plants were raised from seed and the particular plant on Bussey Hill Road is also a seedling… Another canard in circulation is that it is an acid-loving plant. As a matter of fact, it will do equally well on a moderately acid soil or on limestone.” Nobody could doubt his love for the plant, for in the same passage he states “Among the deciduous-leaved shrubs that central and western China has given to American gardens Kolkwitzia stands in the front rank.”
Amazingly, it was not until September 25, 1994, that this beautiful and elusive species was collected again, about 100 miles north of Wilson’s original collection site in Hubei. The participants on the NACPEC expedition to Wudang Shan discovered multiple plants on a hillside near Yan Chi He, and collected ample seed (collector number WD 122). The germinated seedlings at the Arnold Arboretum grew vigorously, and within 18 months were about 0.5 meter (1.6 feet) tall. Unfortunately, all of these plants were sold by mistake at the Arboretum’s plant sale in 1997. This was a striking loss, but fortunately seeds of this collection were grown at other institutions also. In the spirit and interest of sharing material, the Arnold Arboretum received cuttings from 3 plants at the Morris Arboretum in 2008. They have rooted and will eventually be planted out.
Almost everything we know about this species in cultivation can be traced to Wilson’s single introduction event, so we are curious to see how this new collection compares to the original germplasm. No formal studies or evaluations have taken place so far, but there are some preliminary observations that are worth further investigation. Phenological data from the Morton Arboretum from the past 8 years show that the Wilson material on average reaches peak bloom about 1 week earlier than the Wudang Shan material. Perhaps only a minor difference, but this is worth further study. If it holds true, it would be worth selecting for later blooming in self-pollinated F1 and F2 generations of the Wudang Shan germplasm.
Michael Dosmann is Curator of Living Collections at the Arnold Arboretum.