February 4, 2012
What’s Blooming? Magnolias
By Frank McDonough, Arboretum Botanical Information Consultant
Magnolia flowers, some perfumed, some relaxed and spreading, others slender and pointed or even globular burst forth from the barren limbs after shedding their bristly flower caps (called “perules”). They are the largest single flowers outside the tropics. The Arboretum collection contains over 60 different types of magnolias, with over 40 of them being represented in the Meadowbrook section.Although they may appear contemporary, with a look that could be at home in front of an open ceiling mid-century modern style house, these plants have an ancient lineage. Among the first true flowering plants, magnolia fossils over 100 million years old have been found; they came to dominate the pre-ice age landscape across the world from 65 to 1 million years ago. After the glaciers finally receded, the once great forests of magnolias were gone, except for the few temperate areas of the world, like parts of China and North America, that escaped glacial ravaging. Magnolias are pollinated by beetles, common insects of the time. The species that were the starting material for the modern deciduous flowering magnolias came from China. In cultivation there for over 1400 years, monks would collect specimens of Magnolia denudata from the local mountains and transplant them on the temple grounds where they represented the female yin and principles of candor and purity. But it wasn't just the magnolia's beauty that interested the Chinese; magnolia species like M. officinalis and M. denudata were used medicinally as well. Recent research has shown that magnolias are extremely useful medicinally. M. officinalis, called “Hou-phu” by the Chinese, is used for coughs, colds and as a tonic. In a recent experiment published in the Journal of Pharmacology, Honokiol, a compound found in the bark extract of M. officinalis was determined to be five times as potent and much less addictive than Valium for relieving anxiety. Interestingly, a man who probably could have used such a tranquilizer was responsible for the next step in mankind's relationship with this beautiful and useful flowering tree.In the early 19th century, Chevalier Etienne Soulange-Bodin, a disgruntled cavalry officer, treated himself for post traumatic stress by losing himself in the world of plants and gardening. Disgusted with the Napoleonic wars in which he fought (and of which he wrote “It had doubtless been better for both parties to have stayed at home and planted their cabbages”), he founded the Royal Institute of Horticulture at Fromont near Paris. It was Soulange-Bodin who developed the first Magnolia x soulangiana hybrids by carefully transferring pollen from Magnolia liliiflora to the the female flower parts of Magnolia denudata. The hybrid plants that resulted from these crossings sported impressive tulip-like blooms in shades ranging from white, to pink and even darker colors approaching purple. From 1830 on Soulange-Bodin's hybrids became immensely popular in Great Britain, a popularity that has yet to wane and has encouraged other efforts at hybridization.One of those programs was undertaken at the U.S. National Arboretum in Washington D.C. Started by staff geneticist Francis de Vos and continued by horticulturalist William Kosar, their efforts to cross certain varieties of Magnolia liliiflora and Magnolia stellata resulted in a series of eight hybrids that were nicknamed by staff as the “Little Girl Magnolias.” Another ambitious hybridization program was started in Santa Cruz by Magnolia Society founder D. Todd Gresham. Wanting to produce distinctly “Californian” hybrids, he began his efforts with three hybrids chosen for their ability to flower early and their extremes in color and hardiness. From 1955 to 1966 Gresham was able to perform over 300 crosses, resulting in over a thousand hybrid magnolia seedlings, including one growing here at the Arboretum, Magnolia 'Royal Crown'.
Now let's take a tour and look at some of the beautiful magnolias blooming at the Arboretum:Magnolia liliiflora 'Nigra'; M. liliiflora is known as “Mulan” in China and is one of the parents of Magnolia x soulangiana.Magnolia 'Royal Crown', one of D. Todd Gresham's original crosses, is a hybrid between Magnolia liliiflora and M. x veitchii (M. x veitchii is a cross between M. campbellii andM. denudata that was first performed by Peter Veitch of the Royal Nursery at Exeter in 1907).Magnolia 'Royal Crown'Magnolia 'Galaxy' is a cross between M. liliiflora and M. sprengeri that was introduced by the U.S. National Arboretum in the early 1980s. (it was released in 1980). It has a unique pyramid shape to the tree itself and large red-purple flowers that can get as wdie as 8-to-10 inches.Magnolia x soulangiana 'Rustica Rubra', a seedling of Magnolia x soulangiana that appeared in Holland at the turn of the 20th century.Magnolia x soulangiana 'Rustica Rubra' is a seedling of Magnolia x soulangiana, 'Lennei' that was developed in 1893 in Boskoop, Holland.Magnolia x soulangianaMagnolia x loebneri 'Merrill' These magnolias are the result of crossing Magnolia kobus with Magnolia stellata.
Magnolia x soulangiana 'Lilliputian' has beautiful pink flowers on a plant that is 35% smaller than most hybrid magnolias.
Magnolia x soulangiana 'Picture' was found in 1930 growing on the grounds of the Kaga castle in Japan by nurseeryman Koichiro Wada.
Magnolia denudata is known as the “Yulan” or “lily tree” in China where it was venerated as a representation of purity and openness. This species and M. liliiflora are the parents of the M. x soulangiana cross.
Other Flowering Magnolias in Our Collection:Magnolia ‘Ann’ (Magnolia kobus var. stellata x M. liliiflora ’Nigra’) is one of the de Vos and Kosar “Little Girl Magnolia” hybrids from the U.S. National Arboretum. Its red-purple, 2-to-4-inch flowers are some of the first to bloom here at the L.A. County Arboretum & Botanic Garden. Magnolia 'Athene' was developed at the Tikorangi Garden in New Zealand by Felix Jury. It is a mid-season bloomer.Magnolia x brooklynensis 'Woodsman' is a cross between M. acuminata ‘Klassen’ x M. liliiflora ‘O’Neill’. The flower has a combination of yellow, green and purple in tepal. Magnolia x brooklynensis 'Yellow Bird' is, like its name implies, a yellow-flowering magnolia with blooms measuring about three inches across. Magnolia campbellii is pink-flowering species native to Southwest China, East Asia and parts of the Himalayas. It was first collected in Sikkim by Sir Joseph Hooker in 1885. Magnolia cylindrica is a species found on Mount Huangshan north of Nanchang, China.Magnolia 'Jane' (Magnolia liliifora ‘Reflorescens’ x M. stellata ‘Waterlily’)One of the de Vos and Kosar “Little Girl Magnolia” hybrids. Fragrant, late-blooming flowers are red-purple on the outside, white on the inside. Magnolia'Spectrum' (M. liliiflora 'Nigra' x M. sprengeri 'Diva') developed from the same cross made in 1963 at the U.S. National Arboretum that 'Galaxy' was produced from; its fragrant flowers are narrower and more upright than 'Galaxy'. Magnolia x loebneri 'Ballerina' is a cross between Magnolia kobus and Magnolia stellata; this hybrid has the star-shaped flowers of M. stellata and the fragrance of M. kobus. Magnolia x loebneri 'Leonard Messel' is a cross between Magnolia kobus and Magnolia stellata with star-shaped flowers.Magnolia 'Pinkie' (Magnolia liliifora ‘Reflorescens’ x M. stellata ‘Rosea’) opens into pale pink flowers with broad, thick tepals. It has a long flowering period and is one of the most distinctive of the “Little Girl Magnolia” hybrids. The flowers are white inside and pale red-purple outside.Magnolia 'Randy' (Magnolia liliifora ‘Nigra’ x M. stellata ‘Rosea’) is one of the “Little Girl Magnolias” (the de Vos and Kosar hybrids); flowers appear mid to late season and are up to five inches wide. Its sickle-shaped buds open up into blooms that are about 5 inches wide, red-purple on the outside fading on the inside in to a rich pink. Magnolia 'Susan' (Magnolia liliifora ‘Nigra’ x M. stellata ‘Rosea’) (de Vos and Kosar “Little Girl Magnolias”) has pink, straplike tepals. Magnolia salicifolia is a Japanese native first found on Honshu Island on the slopes of Mt. Hakkoda between 2,000-3,000 feet above sn ea level. The small, floppy, white flowers are fragrant and the leaves produce a lemony, anise-like fragrance when crushed. Magnolia salicifolia cultivars in our collection include Magnolia salicifolia 'Miss Jack' and Magnolia salicifolia 'W. B. Clark'.Magnolia schiedeana is a threatened, evergreen cloud forest (between 4,600-7,200 feet) species from Mexico. Its flowers are near perfect, have no nectar and open in the morning. They are pollinated by Cyclocephala jalapensis, a scarab beetle. Its flowers are females in the morning emitting a scent that attracts beetles to feed on the tree's fleshy petals. Later on in the afternoon the anthers emerge from the flowers to offer the beetles another treat they find irresistible: the plant's pollen.Magnolia x soulangiana 'Alexandrina' is a cultivar that originated in Paris, France in 1831. Magnolia x soulangiana 'Amabilis' is a cultivar that originated in France in the 1850's. Magnolia x soulangiana 'Grace McDade' was developed by Clint McDade of Semmes Nursery in Semmes, Alabama in 1945. It has beautiful, large pink flowers. Magnolia x soulangiana 'Lennei' was developed in Italy around 1830; it is named after the superintendent of the Prussian Royal Garden developed by Peter Lenne. It has large, globose petals that are white on the inside and pink on the outside. Magnolia x soulangiana 'Speciosa' is a late blooming M. x soulangiana that is shorter than most of the other crosses. It originated in France or Belgium in the 1830's. Magnolia x soulangiana 'Verbanica' is a late blooming, narrow petaled pink M. x soulangiana that is late blooming. Magnolia stellata (actually Magnolia kobus var. stellata ) is a natural variety of Magnolia kobus endemic to the Mie, Gifu and Aichi prefectures of central Honshu, Japan where it grows on sunny slopes in damp, swampy soil. Its star-like, small, white flowers earn it its name. Magnolia stellata 'Royal Star' (actually Magnolia kobus var. stellata cv. 'Royal Star' ) is a seedling selection of M. stellata that originated at the J.Vermeulen and Sons nursery in New Jersey. It is larger than its parent Magnolia stellata and is pink, not white. Magnolia x veitchii is a cross between Magnolia campbellii and Magnolia denudata made in 1907 by Peter Veitch of the Royal Nurseries in Exeter, England. It is a vigorous bloomer with pear-shaped, salmon-pink flowers. Click here for a map of all the flowering magnolias located in the south Meadowbrook area that you can send to your GPS equipped smart phone and use to find the varieties mentioned in this article. For those who are inspired by the beauty of these magnolias, the following list of books and references on magnolias are available at the Arboretum:Asiatic Magnolias in Cultivation. With a foreword by the D. Bowes-Lyon. Author: Johnstone, George Horace. Call Number: QK495 .M24 J72a Publisher: London, The Royal Horticultural Society, 1955. Checklist of the Cultivated Magnolias / prepared by The American Horticultural Society;with the cooperation of The American Magnolia Society. Call Number: SB413 .M19 A512c Publisher: Mt. Vernon, Va. : American Horticultural Society, 1975. Magnolias / James M. Gardiner ; [illustration, David Ashby]. Author: Gardiner, James M. (James Milton), 1946- Call Number: SB413 .M19 G222m Publisher: Chester, Conn. : Globe Pequot Press, 1989. Magnolias / Neil G. Treseder. Author: Treseder, Neil G. Call Number: SB413 .M19 T797m Publisher: London ; Boston : Faber & Faber published in collaboration with the Royal Horticultural Society, 1978. Magnolias : A Gardener's Guide / Jim Gardiner. Author: Gardiner, James M. (James Milton), 1946- Call Number: SB413 .M19 G222m 2000 Publisher: Portland, Or. : Timber Press, c2000. Magnolias, by J.G. Millais … with illustrations by R. Millais and from photographs. Author: Millais, John Guille, 1865-1931. Call Number: QK495 .M24 M645m Publisher: London, New York [etc.] Longmans, Green and Co., 1927. The World of Magnolias / Dorothy J. Callaway. Author: Callaway, Dorothy J. (Dorothy Johnson) Call Number: SB413 .M19 C156w Publisher: Portland, Or. : Timber Press, c1994.Magnolia Checklist Online: http://www.magnoliasociety.org/checklist_ndx.html