Magnolia sieboldii also called “Mongnan” or “Mokran” (목란; 木蘭) is the national flower of North Korea. It is usually grown as an ornamental tree in gardens. This species, Magnolia Sieboldii is one of the hardiest magnolias that can thrive in difficult environment and can be found  as far north as the Arboretum in Finland.

It  is a large shrub or consider as small tree 5–10 m tall. The stalks, young leaves, young twigs and young buds are downy. The leaves are elliptical to ovate-oblong, 9-16 cm (rarely 25 cm) long and 4-10 cm (rarely 12 cm) broad. The flowers, unlike the better-known spring flowering  species of  Magnolias, blossoming primarily only in early summer and continue intermittently until late summer. The flowers are pendulous, cup-shaped, 7-10 cm diameter, and have 6-12 petals with the outer three smaller tepals and the remaining larger white petals.  The carpels are greenish and the stamens can be reddish-purple or greenish-white.The magnolia also produces a reddish-brown cone-like fruit in the center of the flower, which contains the seeds.  The fruit is a source of food for birds.

Interesting to note

Some people have mistaken Kimilsungia flower, a hybrid cultivar of orchid Dendrobium ‘Kim Il-sung’ of orchid is North Korea’s national flower.  An interesting article explaining about the history of  Kimilsungia (name after Kim Il Sung and Indonesia) can be found here.

Another flower commonly mistaken is the Kimjongilia which is named after the late North Korean leader,  Kim Il-Sung’s son, Kim Jong-Il. Kimjongilia  is a hybrid cultivar of tuberous begonia.  

Both Kimilsungia and Kimjongilia are not national flowers of North Korea though  large scale exhibitions of these two flowers were held annually in North Korea.

http://en.wikipedia.org/wiki/Magnolia_sieboldii 

http://www.theblogfarm.com/fun-flower-facts-magnolia/