For many years magnolia growers wondered if it would be possible to breed a hardy tall tree, whose flowers appeared well before its leaves emerged, but with yellow rather than the normal pink flowers. It became a kind of arboreal Holy Grail.
The secret of the successful introduction of fine yellow magnolias stems from a species called Magnolia acuminata, first discovered by John Clayton in Virginia around 1700 and named by Swedish Botanist Carl Linnaeus in 1753. Its common name is the Cucumber Tree or Cucumber Magnolia, referring to its seed pods which resemble a sea cucumber rather than what we know as a vegetable.
The secret of M.acuminata in the breeding world is its variability. It has a huge geographic range with several sub-species that have more yellowish flowers. The sub-species which the breeders homed in on is known as Magnolia acuminata var. subcordata and it lay at the centre of the quest to obtain a true yellow magnolia.
The first hybrid was named “Elizabeth” bred in the Brooklyn Botanic Garden in 1956 and named in honour of its director Elizabeth Scholz. “Elizabeth” most closely resembles M. acuminata with its dark green elliptical foliage which is tinged bronze at first. Its flowers are closer to M.denudata with their spreading tulip shape. They have little scent but attractive red stamens. However, “Elizabeth” is only yellowish in bud, quickly fading to a creamy white.
The next early hybrid was “Butterflies”, whose flowers are a bit more yellow than “Elizabeth” but fade to cream even more quickly.
In the second generation breeders produced five varieties. “Miss Honeybee”, which seems to have misshapen petals, although with a definite scent. Then came “Gold Star”, a cross that was never likely to create a world beating yellow because one of its constituents is white. But it did produce a delicate greenish yellow bud that also fades to a creamy white.
“Yellow Fever” has flowers that are more full than “Miss Honeybee”, but they are really cream. It was followed by “Yellow Lantern”, a further step in the right direction but whose yellowness proved rather insipid. Chinese growers offered “Yellow River” (or “Fei Huang”), but it turned out to be a form of M. denudata in disguise. Finally, “Yellow Bird” arrived (photo right) and this is the one everyone loves, with strong yellow flowers that hardly fade at all. It was bred at the Brooklyn Botanic Garden in 1967 and made its debut in 1981.
Growers are now into a third generation of hybrid yellow magnolias. They include “Daphne”, which is genuinely yellow and long lasting; “Lois”, a darker yellow than “Elizabeth”; “Sundance”, which has received mixed accolades; and “Stellar Acclaim”, which has a greenish tinge in bud that resolves into a less than satisfactory yellow.
You can please all of the people some of the time, some of the people all of the time, but not all of the people all of the time. The best bet for lovers of yellow magnolias is going to be “Yellow Bird” or “Daphne” – both of which are hardy and eye-catching.
Early references to magnolias refer to their medicinal properties. The flower buds of Magnolia salicifolia are used in Asia to treat headaches and allergies and a 1985 study refers to the potential use of this drug in the treatment of cancer. Another study found that tonics from the bark of Magnolia officinalis lessen tremor in patients with Parkinson’s disease. There may be much more to discover.
Meanwhile, there are still 80 species of magnolia to explore in the world. And, surprisingly, one of its closest genetic relations is the buttercup – which may be why yellow is an inherent trait. Elementary!