In the winter of 2008-2009 we planted 3 Davidia involucrata in the Moss Family Temperate Woodland Garden at Humboldt Botanical Garden. The trees were in 5 gallon pots so were quite small. The Davidia involucrata planted in the center of the garden was posthumously dedicated to Larry Moss. We thought that the cultivar we got was “Sonoma' which was reputed to bloom young at 3 to 5 years. Here we are in May 2020 seeing our first blooms on 2 of our trees, thus we probably received the species Davidia involucrata var. vilmoriniana.
Tim and I have seen mature trees in our garden travels in Eastern USA, British Columbia, England, Scotland and Wales and have been anxious to see the HBG trees fulfill their promise of lovely fluttering white handkerchief or dove ‘flowers' in spring.
The trees are in the family Nyssaceae, which includes the North American Tupelo trees. Previously they were in the family Cornaceae which includes dogwoods. When you see the flowers you can see why taxonomists put them in that family originally. The cluster of tiny purplish-red flowers is framed by two bracts; an upper bract and a lower much larger bract, 6 to 10 inches long, of pure white when completely open.
There are 2 species; Davidia involucrata and Davidia involucrata var. vilmoriniana, which is what we have. The two, having different numbers of chromosomes, when crossed produce infertile offspring. They can grow to 80 feet tall in the wild but tend to be closer to 40 feet in cultivation. They are somewhat tender (zones 6-9) and need wind protection. Good moisture retentive soil is best.
The trees were first described by Father Armand David (1826–1900; "Père David"), a French missionary living in China. In 1869 he had found them in a mountainous area of Sichuan above 6,500 feet altitude. In 1871 he sent dried specimens to Paris. It wasn't until 30 years later, in 1902, that plant hunter Ernest Henry Wilson (E. H. Wilson or “Chinese Wilson”) brought seeds back to Britain for propagation. E.H. Wilson brought them to the United States in 1904.
By June Walsh, 2010 Master Gardener and Co-curator of the Moss Family Temperate Woodland Garden at Humboldt Botanical Garden
Sources:
Trees and Shrubs, Ernie Wasson
Trees and Shrubs for Temperate Climates, Gordon Courtright
In the Footsteps of Augustine Henry, Seamus O'Brien