Siebold's Magnolia: A Guide to the Korean Mountain Magnolia
Magnolia sieboldii, commonly known as Siebold's magnolia, Korean mountain magnolia, or Oyama magnolia, is a striking species native to the diverse landscapes of East Asia, including China, Japan, and Korea. Named in honor of the German physician Philipp Franz von Siebold (1796–1866), this plant holds significant cultural and botanical importance across its native range.
Beyond its aesthetic appeal, the species carries deep symbolic weight; it is recognized as the national flower of North Korea, where it is known as mongnan or mokran.
ไม่มีภาพประกอบKey Facts
- Scientific Name: Magnolia sieboldii
- Native Range: China, Japan, and Korea
- Growth Habit: Large deciduous shrub or small tree (5–10 m tall)
- Flowering Period: Early summer through late summer
- Conservation Status: Least Concern (IUCN 3.1)
- Cultural Significance: National flower of North Korea
Botanical Description and Characteristics
Siebold's magnolia is characterized as a large deciduous plant—meaning it sheds its leaves annually—that can grow into a shrub or a small tree reaching heights of 5 to 10 meters (16–33 feet). A distinguishing feature of its anatomy is the presence of downy textures on its stalks, young leaves, twigs, and buds.
The leaves are typically elliptical to ovate-oblong in shape, measuring between 9–16 cm in length and 4–10 cm in width, though they can occasionally reach larger dimensions. The petiole, or the stalk that joins a leaf to a stem, generally measures between 1.5 and 4.5 cm.
Flower budUnique Flowering Patterns
Unlike many other magnolia species that bloom in the early spring, Magnolia sieboldii follows a different schedule. Its flowers primarily open in the early summer and continue to appear intermittently until late summer. The flowers are pendulous (hanging downwards) and cup-shaped, typically measuring 7–10 cm in diameter.
Each flower consists of 6–12 tepals—a term used when petals and sepals are indistinguishable. The outer three tepals are smaller, while the remaining ones are larger and pure white. The center of the flower features greenish carpels (the female reproductive parts) and stamens that range from reddish-purple to greenish-white.
Flower, male phase Flower Flower detailTaxonomy and Subspecies
First described by Karl Koch in 1853, the species is classified within the family Magnoliaceae. Botanists recognize three distinct subspecies, which vary based on their geographic location and physical traits:
- Magnolia sieboldii subsp. japonica: Found in Japan, this is a low shrub featuring flowers with 6 tepals and greenish-white stamens.
- Magnolia sieboldii subsp. sieboldii: Native to Japan, Korea, and eastern China, this subspecies grows as a tree or large shrub with 9–12 tepals and reddish-purple stamens.
- Magnolia sieboldii subsp. sinensis: Located in southwestern China (Sichuan), this subspecies features larger leaves, commonly reaching up to 22 cm.
Cultivation and Gardening
Due to its beauty, Siebold's magnolia is a popular choice for ornamental gardening. It is noted for being one of the hardiest magnolias available, capable of thriving in northern climates such as the Arboretum Mustila in Finland. For gardeners seeking specific varieties, the cultivar 'Colossus' has been honored with the Royal Horticultural Society's Award of Garden Merit.
Summary of Classification and Traits
| Category | Details |
|---|---|
| Kingdom | Plantae |
| Order | Magnoliales |
| Family | Magnoliaceae |
| Genus | Magnolia |
| Common Names | Korean mountain magnolia, Oyama magnolia |
| Typical Height | 5–10 m |
Frequently Asked Questions
When does Siebold's magnolia bloom?
Unlike many spring-blooming magnolias, this species flowers in the early summer and can continue to bloom intermittently through late summer.
Is this plant hardy in cold climates?
Yes, it is considered one of the hardiest magnolias and has been successfully cultivated in northern regions like Finland.
What is the difference between a petal and a tepal?
In many flowers, petals and sepals are distinct. In species like the magnolia, these parts look so similar that they are referred to collectively as tepals.
What is the national flower of North Korea?
The Siebold's magnolia, known locally as mokran or mongnan, is the national flower of North Korea.
How large can the leaves grow?
While most leaves are between 9–16 cm long, they can occasionally reach up to 25 cm in length.