In perusing my handwritten journal from the 1994 NACPEC trip to Wudang Shan in Hubei Province, China, I found the following entries regarding the Chinese stewartia, Stewartia sinensis:
Monday, September 19, 1994: “The other highlight [besides finding Acer griseum] was to see Stewartia sinensis—the biggest plant I’ve seen of any Stewartia—about 30 inches [76 centimeters] in diameter at the base and 50 feet [15 meters] tall, with a clear bole for the first 20 to 30 feet [6 to 9 meters]. The bark was a buff/tan color— carried high up into the crown—and absolutely smooth with little or no flaking. Certainly the most magnificent tree I saw on Wudang Shan. It should also be noted that a spot right next to the Stewartia, above it to be precise, was selected as a site for a public toilet—and it was disgusting to the point that no one but me dared to go near the tree. Perhaps that is the secret to its vigor.”
Tuesday, September 20, 1994: “Up the mountain again, then a quick turn to the east at about 1300 meters [4,265 feet] and off into the woods. It was misty and rainy the whole day, giving the whole place a great air of mystery… The rain and heavy fog limited our visibility pretty much to what was immediately beside the path—but there was so much. After about an hour or so on the path, we came upon an incredible house nestled under the cliffs. It looked like it had been there forever—no one was around so I took a few pictures. It really felt like the same China that Wilson saw. A little ways beyond the house and garden we came to a bend in the road where it looped back into a ravine. Our guide, Mr. Zeng, a collector of medicinal plants among other things, pointed out a beautiful specimen of Stewartia sinensis, and then we saw another, both with the beautiful, rich, smooth, cinnamon-red bark—a wonder to behold and to touch! Cornus kousa was there too, and a small (4 inch [10 centimeter] diameter) specimen of Acer griseum. All within the narrow space of ten square meters—I felt as though I’d died and gone to horticultural heaven. The only thing missing, sadly, was seeds on any of the plants. The conditions were moist and shady and steep, with an oak overstory.”
It was in this location—Hubei Horticultural Heaven we called it—that I noticed a small Stewartia seedling, about 20 centimeters (8 inches) tall with a distinct kink at its base, growing along the edge of the path. I immediately stopped and dug it up while the other members of the party went on ahead. At the end of the expedition, the plant was washed clean of soil and packed in moist sphagnum moss for shipment back to the United States. The plant passed inspection at the USDA inspection station at Beltsville, Maryland, and, after 48 days on the road, arrived at the Arnold Arboretum on November 7, 1994. It was immediately potted up, assigned the accession number 691-94, and left to overwinter in a cool greenhouse.
The seedling was moved to the outdoor nursery in spring 1996, and it grew to a height of 1.1 meters (3.6 feet) by the end of July. In spring 2000, it was moved from the nursery to the grounds, where it has proved to be completely hardy. By the end of the 2009 growing season, the plant was 4.7 meters (15.4 feet) tall and 4.1 meters (13.5 feet) wide with two co-dominant trunks arising from the stout base which is 14 centimeters (5.5 inches) in diameter. The plant flowered for the first time in the summer of 2002 and has gone on to flower every year since. The flowers, which are produced from the end of June through mid July, are 6 to 7 centimeters (2.4 to 2.8 inches) across with beautiful light lemon yellow anther filaments and short pedicels, indicating that it is S. sinensis var. sinensis according to the Flora of China. In Boston, the new leaves emerge in early May and are distinctly hairy and tinged with red anthocyanin pigment; both features disappear within a week or so. The bark is cinnamon-red where it is not exfoliating and olive-green where the bark has peeled off in fine, papery flakes. Over time, I’m sure the tree will develop mature bark that is “smooth as alabaster and the colour of weathered sandstone” (to quote W. J. Bean), like the magnificent specimen we saw on Wudang Shan.
Peter Del Tredici is a Senior Research Scientist at the Arnold Arboretum.