The Latest Export From China -- Garden Plants

Among the trees growing at the Lam garden, Justice said, is the chocolate maple, named after the dark brown hue of the emerging leaves in the spring. "Young stems are deep purple green, often almost black, and in winter show up the lighter colored buds and vertical flecks of developing bark," he wrote.

One of the most striking woody plants in the book is a monkeytail hornbeam, a small, dense and rounded tree named for its trailing white catkins. The leaves, too, are "extraordinary," he says, up to eight inches long and emerging a purple-bronze color in the distinctive corrugated foliage of hornbeams.

Justice rates its hardiness at Zone 8, meaning it would only survive long-term with shelter in gardens inside the Beltway. But the estimation is conservative, it may well flourish in a much colder location. Like a lot of this material, it hasn't been tested much in North America, he said.

For Justice, one of the most exciting plantings is the small, delicate Chinese parasol storax. It blooms in early spring, early enough that its blossoms can be damaged by late freezes, but when the flowers are fully open "they resemble little floating parasols among the young, pea-green foliage."

Gardeners who cannot get enough late-season bloomers may be drawn to the Hong Kong evodia: Pictures in the book show a small tree of unusual breadth, and covered in elderberry-like flowers in late October. Justice lists it as hardy to Zone 8, but like the monkeytail hornbeam, it may be tougher. A hardier relative to the evodia is the Chinese bee tree, which flowers in late summer. "Each flower produces copious nectar, and trees in bloom are mobbed by bees," he wrote.

In an interview, he said that "many of the plants we are talking about have been collected before, whether or not they still exist in North America, or only in botanical gardens, is a good question."

A few specialty nurseries have pioneered the introduction of recent Chinese and other East Asian discoveries, including Asiatica ( http://www.asiaticanursery.com/ ); Heronswood Nursery ( http://www.heronswood.com/ ) and Plant Delights Nursery ( http://www.plantdelights.com/ ).

Western explorers to China's remote regions form a pantheon of horticultural Indiana Joneses. One of the most intrepid and imperiled is the subject of a recent biography: "George Forrest: Plant Hunter," by Brenda McLean (Antique Collectors' Club, $59.50).