"It is perfectly hardy, but has unfortunately the great drawback of requiring a mild spring and the absence of late frosts to enable it to expand its beautiful flowers, which appear before the leaves and have no protection save the bud-sheath, which falls away when the flower-bud begins to swell. It may be counted on to bloom about every third or fourth year, flowering very freely when it does so, my tree having produced 147 fine flowers in the spring of 1902 and not one in either 1903 or 1904."
This illustration and the description are from volume two of "Flora and sylva. A monthly review for lovers of garden, woodland, tree or flower" edited by William Robinson, 1838-1935. (Published in London, 1903-1905)