Clematis cadmia Buchanan-Hamilton ex J. D. Hooker & Thomson

Clematis of the Month for March 2018

C. cadmia©Ton Hannink

described by Ton Hannink

Section: Viticella

Subsection: Floridae

Species: C. cadmia and C. flore pleno

Distribution: China prov. − Guangdong, Hunan, Jiangxi, Anhui, Jiangsu and Zhejiang, in India – Gorakhpur, Khasi Hills, Manipur, Sikkim, Assam and in Burma.

Flowering: April − May

Habitat: Grassy areas, along streams and grows even in water. Clematis cadmia flourishes ca. 100 m

First Recorded: Hooker & Thomson in Fl. Ind. 1: 5. 1855.The flowers of C. cadmia are single, flat and 8 − 12 cm in diameter and scented. Color is from white to lilac.

Tepals 6 and 3 − 5 cm long. The anthers are yellow to light brown-red. The pistils are white in contrast to all the other members of the subsection Floridae!

The seeds are big and non plumose. They germinate very well after 2 − 6 months.

Height is about 2 − 3 meters.

C. cadmia©Ton Hannink

When I got my first young plants from China I had no idea about the properties of this species. In a few books there was some information that this species could be very interesting for hobbyists. I placed the plants in the greenhouse because I did not know anything about their hardiness. In the greenhouse I also had all my tropical container plants and on one morning there was a lot of scent in my part of the greenhouse. I looked to see which of my tropical plants could be the source. However, it was not a container plant but C. cadmia which had the scent. I was very surprised because I had found no information in books or articles about this species. What was known is that no member of subsection Floridae has scent. The scent differs between the different plants but not a lot. There were only a few flowers on the plants.

C. cadmia©Ton Hannink

C. cadmia is a very useful clematis in the garden for growing in small shrubs and small trees. If you make a good combination, then you have in Spring a shrub or tree with scented flowers. The plant is also useful for a trellis. Place this clematis so in the garden and you can enjoy the nice scent in Spring. Alternately keep the plant in a container − the plant is not so high.

I also made also some crossings, which have never done before, with C. cadmia and the results are scented flowers and strong scented flowers. This species can be interesting in the crossings of the future as it offers new possibilities.

Hardiness: I have rather good results and the plant is hardy in Holland.

Pruning is needed if you want to have a lot of flowers. This species is different from C. floridaC. xiangguiensis and C. courtoisii with the kind of flowering. C. cadmia flowers properly only once each year instead of three times a year. There is a second time but there are only a few flowers. Therefore, you must prune the plant very hard in Autumn, just before the frosts start. In Spring you get a lot of new stems and on the new stems you get the buds and later the flowers. The older the plant, the greater the amount of very nice scented flowers.

Ton Hannink 
Ton Hannink