Magnolia trees are cherished for their striking beauty and often fragrant blooms, making them a popular choice in gardens and landscapes worldwide. These ancient plants, part of the Magnoliaceae family, are recognized for their large flowers that frequently signal the arrival of spring. The variety within the genus Magnolia includes both deciduous and evergreen species, contributing to their widespread appeal.
The Iconic White and Cream Magnolia
Many people primarily associate magnolias with their classic white or creamy-white blossoms. The Southern Magnolia (Magnolia grandiflora) features fragrant, creamy-white, cup-shaped flowers up to 8 to 12 inches in diameter. These waxy blooms typically appear from late spring into early summer. Their petals have a thick texture, emitting a strong lemon-citronella scent.
Another white-flowered species is the Yulan Magnolia (Magnolia denudata), native to central and eastern China. Its upright, cup-shaped flowers are typically creamy to ivory white, measuring 5 to 6 inches across, and emerge on bare branches in late winter to early spring. These blossoms can sometimes show a pink tinge at their base and possess a citrus-lemon fragrance. Similarly, the Star Magnolia (Magnolia stellata) is known for its white flowers, which are star-shaped with numerous thin, delicate petal-like tepals.
Exploring Magnolia Color Variations
Beyond the traditional white and cream, magnolias display a spectrum of colors, including various shades of pink, purple, and yellow. Pink hues are common, appearing in species like the Star Magnolia, where flowers can range from pure white to rich pink. Saucer Magnolias (Magnolia × soulangeana), a hybrid, often feature white blooms with pink interiors or lavender-pink bases, and popular cultivars like ‘Lilliputian’ display smaller pink flowers.
Purple and reddish-purple magnolias offer a deeper visual. Magnolia liliiflora, known as the Lily Magnolia, produces tulip-shaped flowers that are purplish on the exterior and creamy white inside. Cultivars such as ‘Susan’ are known for their fragrant reddish-purple or fuchsia flowers, which have paler interiors and bloom in mid to late spring. For even darker shades, ‘Black Tulip’ magnolias showcase deep burgundy, almost black, tulip-shaped flowers up to 6 inches across, while ‘Genie’ offers deep burgundy-wine to maroon blooms.
Yellow magnolias, though less common, provide a bright contrast. ‘Butterflies’ is a notable cultivar, featuring upright yellow flowers that can be 4-5 inches across and possess a light lemon oil aroma. Another yellow variety, ‘Yellow Fever’, produces cup-shaped, fragrant cream-yellow flowers that may have a light pink flush at the base before fading to cream. The Cucumber Tree (Magnolia acuminata) can also produce flowers in shades of yellow and yellow-green, though these often blend with the foliage.
What Determines a Magnolia’s Color?
The diverse coloration observed in magnolia flowers is primarily determined by their genetic makeup, which dictates the production and concentration of specific pigments. Flavonoids, a class of plant compounds, play a significant role in this process. Anthocyanins are largely responsible for the red, purple, and pink shades found in many magnolia varieties. Specifically, pigments like cyanidin and peonidin contribute to the red-purple and purple appearances of magnolia petals.
Conversely, white and yellow-green magnolia flowers typically lack anthocyanins. Instead, their coloration is influenced by other flavonoids, such as flavonols like quercetin, kaempferol, and isorhamnetin, which can act as auxiliary pigments. The specific combination and amount of these pigments, along with the structural properties of the petals, dictate the final perceived color. Hybrid breeding programs have also been key in expanding the color palette of magnolias. By crossbreeding different species, horticulturists have developed new cultivars with unique color variations, such as the deep purples and yellows seen today.