The Nature of Eureka

By
Steven Foster
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605
Clematis terniflora, Sweet autumn virgini's bower, yam-leaved Clematis, Sweet autumn Clematis. The Asian invasive alien Clematis terniflora, was introduced to European botanical gardens around 1826. It grows naturally in China, Japan, Korea, Mongolia and Russia. Now it is widely naturalized in North America. The root of C. chinensis and C. terniflora are both source of wei-ling-xian which is used to relieve arthritic conditions, neuralgia and rheumatism. Historically the American species C. virginiana has been used similarly. Both contain protoanemonins which are substance found in many members of the buttercup family that are extremely acrid and caustic, both internally or externally applied. Whether that caution relates just to this one compound or the whole plant is unknown to me. If the fresh leaves are applied to the skin, they will cause blistering. Traditionally, both in Chinese and American folk traditions the plant has been used to treat rheumatism as a “counterirritant.” In other words, the purpose is to produce irritation perhaps to distract one from pain.

Invading Aliens Climb the Wall

Look! On the fencerow – it’s a wildflower, it’s a perfume plant, it’s a bombshell beauty! No, it’s super weed! Oh, yes I know, it’s a pretty thing with a delightful fragrance and produces a festoonery of beautiful, wedding-dress-cream-white flowers reminding us of the charm of nature, but above all, it’s an invasive alien.

Don’t build a wall to keep it out. It climbs walls. Yes, it’s a lovely stunner in terms of visual appeal, and because of these features, along with being really easy to grow, it found a wayward home in North America and elsewhere after introduced from its native home in East Asia (China, Japan, Korea), after its initial introduction in 1826.

European botanists, most of whom had not seen the plant in the wild, were happy to name it for their pals, names such as – Clematis maximowicziana (for Carl John Maximowicz, 1827-1891), or because it looked like something else, such as wild yam leaves, becoming Clematis dioscoreifolia, or the Romanesque technical Clematis paniculata, the flamboyant Clematis flammula. Finally, botanists settled on the less than elegant, Clematis terniflora, a name first bestowed on it in 1817. Terniflora means “3-leaved,” yet our plant typically has 5-7 leaflets, so the name doesn’t quite fit.

How many times in the last week have I received text messages, emails, FaceBook inquiries, and tweets asking me what the beautiful white flowers are that decorate our fences, field edges and roadsides, largely confined to in-town Eureka Springs, but spreading prolifically along the edges of town as well. I can’t quantify how much more biomass of the thing there is now compared with ten years ago, but I would guess the increase is four-fold.

It’s given the delicate names sweet virgin’s bower, fragrant virgin’s bower, sweet autumn clematis, and yam-leaved clematis among others. When you go to remove the woody vines, especially during the active growing season, you will want to cover your skin, because like many members of the Ranunculaceae (buttercup family) the plant contains acrid, caustic protoanemonins, which can cause contact dermatitis with blistering and an irritating rash.

In both American and Asian folk traditions, the fresh leaves have been applied to the skin as a counterirritant to treat rheumatism. The logic is a little like if you think rheumatism is bad, here, try this, it will divert your attention, giving new meaning to the phrase, “beauty is only skin deep.”