Clematis tangutica (Yellow Clematis) - photos and description




Last year's seed head to the left of the flower. 

Sepals pulled back to show stamens.

The stamens are comprised of anthers containing pollen, and their stalks called filaments.

Hairs are evident on stamens (their filaments) on the left and right of the photo.

Leaves opposite, 1-pinnate with 3 leaflets.


General: Climbing plants, with woody stems. Stems pubescent, particularly on nodes where the leaves attach. This plant is designated as a noxious weed in Alberta.

Flowers: Flowers yellow, the flowers with showy sepals and no petals. bell-shaped, hang downwards, solitary. We measured sepals 4 cm long, and flowers 2 cm diameter. The stamens are pubescent. The flowers grow on current year's branches not on previous year's branches.

Leaves: Leaves are opposite, trifoliate, the middle leaflet much longer than the two lateral leaflets.  The leaflets are linear-lanceolate, and either denticulate or with a few irregular sharp teeth. Leaflets top and bottom with fine, short hairs. We measured a large, middle leaflet at 7.5 cm long and 2 cm wide.

Budd's Flora, The Flora of Canada, Flora of Alberta, and Flora of North America all describe this plant as having leaves with 5 to 9 leaflets. All of the leaves of the plants we observed had leaves with only 1 to 3 leaflets, mostly 3 leaflets.

After reading the above descriptions, I was still pretty sure this plant C. tangutica because there aren't many yellow-flowered Clematis, and I found it unlikely we stumbled across a new species of Clematis undescribed by the above floras. So... because this plant is native to China I looked up the plant in the Flora of China which is available online, in English.

(link might be slow to load) Clematis species in Flora of China

C. tangutica is described in the Flora of China as having leaves 1- or 2-pinnate and NOT having leaves with 5 to 9 leaflets as described in the North American floras listed above. I followed the Clematis key from the Flora of China and the plants we observed keyed to Clematis tangutica.

Height: We measured plants to over 2 metres tall.

Habitat: Waste ground in cities, often growing on fences.

Abundance: Uncommon.

Origin: Introduced.

When and where photographed: The above photos were taken June 20th along a bike path in our home of Regina, SK.