This is a columnar cultivar of persian ironwood described in 2006 Great Plant Picks. Based on description and photos, this seems to be an ideal tree for small gardens. 20 feet high, 5-8 feet in diameter, beautiful in all four seasons, drought tolerant and with a tap root that doesn't interfere with pavement. Several nurseries in Oregon sell it but don't ship to Canada. I've talked to them and they seem to have it regularly in stock. Does anybody know a nursery in B.C. that might have it or be able to import it?
Don't count on the 20 ft. height cutoff. There are parrotia in North America three times that height. The distinctive feature of this one is the branches clapped together in a parallel fashion instead of angling outward to produce a giant vaselike bush (cutting-grown) or pyramidal tree (seedlings, showing natural habit). All trees have surface roots, some are more apt to make thick surface roots that lift pavement but those that do not aren't doing it because they are sending all their roots down (as tap roots or otherwise).