Clematis ianthina Koehne (sensu Nakai)

Clematis of the Month for August 2010

C. ianthina©Ton Hannink

Section: Viorna
Subsection: Fuscae
Distribution: China: N. China, Manshuria, the Amurand Ussuri areas, Korea
Flowering: July-September
Habitat: Mostly in thickets and also in grassy meadow and in forest margins
First Recorded: E. Koehne in Deutsche Dendrologie 159, 1893
First Discovered:
Remarks: Syn. fusca var. violacea. Ianthina and violacea mean violet.

C. ianthina©Ton Hannink

The flowers of Clematis ianthina are nodding and blue violet to purple violet, between 2 – 3.5 cm long and 2 – 2.5 cm in diameter, though sometimes you see very bulky flowers at least 5 cm long and 5 cm diameter. The colour of the flowers is also variable. The flowers are always in pairs in the nodes except the one at the end of the stem. Most plants have 4 sepals though some can have 4 – 6 sepals. The sepals are very hairy and more or less bent outwards at the end. The filaments are also very hairy. If the flowers are wet from the rain then they are very violet.

C. ianthina©Ton Hannink

C. ianthina flowers from July to September. The plant can have a second flowering if you cut the stem after the first flowering. Seeds appear very easily and are large in size.

C. ianthina©Ton Hannink

The stems grow to 2 – 4 meters long as they die back and grow new stems each year. Place the plant at a sunny place and you will have a lot of flowers. The plant prefers acid, neutral and basic (alkaline) soils. It is a species without difficulties or problems, a very healthy species.

C. ianthina©Ton Hannink

The plant can be used in a border or climbing in a small tree or shrub. A combination with a light green shrub or tree is the best because then you will see the rather dark flowers. The combination with light plants in the border is also a good choice so that you see these special flowers and also the special colour for the flower.

Pruning is not needed because the stem dies naturally. Remove the dead stems and next year, new green stems will start growing. Pruning during summer gives a second flush of flowers.

C. ianthina©Ton Hannink

Propagation from seeds is very easy because the seeds are very big and most are fertile. They germinate after 6 months or so. The young plants grow quite fast and you will normally get flowers in the second year. In these seedlings there can be variation in colour of the flowers. Cuttings can be made from not too young stems but this is not very easy.

In summary, this species is very useful in the garden because it flowers easily and freely, is not difficult and has no diseases.

Ton Hannink 
Ton Hannink