by Chris Bidwell

One of our showiest/rarest leather flower vines, swamp leather flower or blue jasmine is a member of the Ranunculaceae (buttercup/crowfoot) plant family.  It is one of seven native species in the genus clematis found in Kentucky – worldwide there are approximately 300 clematis species.  Swamp leather flower is a perennial, deciduous, climbing/twining, herbaceous, multi-angled, branching vine.  The purplish-blue green vine can reach up to 10 feet long with adequate support to prevent the flexible yet weak vine from breaking. Smooth ovate/lanceolate leaves are opposite/pinnate with 3-5 entire leaflets. Clematic crispa produces very attractive urn-shaped, curled-back flowers that are composed of 4 wavy, crimped, thick textured sepals.  There are no petals.  The flowers hang upside down (see accompanying photos).

The flowers reach up to 2” long and 1” wide in the calyx. Clematis crispa is usually a beautiful light purple-blue colored flower – but pure white, pink, blue purple, or mixed hues are occasionally produced. Plants can bloom from early spring to early fall (April-August). Flowers possess a mild pleasant fragrance. One-seeded fruits are flat achenes with an elongated persistent 1” curved style that effectively facilitates its wind borne, hitch-hiker/mammal, and water dispersal.  Swamp leather flower dies back to the ground in the fall and reappears in early spring. 
Clematis crispa’s common name, swamp leather flower, is derived from its habitat – facultative wetland (FACW) which includes wet woods, swamps, sloughs, and any persistent damp-moist areas. In Kentucky it is found in the Mississippi Embayment (Jackson Purchase) in Carlisle, Hickman, and Fulton Counties. It is an imperiled/threatened species in KY primarily due to wetland habitat loss. Clematis crispa is hardy in zones 5-9.

The genus name, Clematis, is from the Greek word(s) klematis/klema, which means climbing plants or a branch of a vine.  The species name, crispa, is from the Latin word(s) crispus/crispa/crispum meaning finely waved, closely curled, elegant, trembling, vibrating, wrinkled, and twisted in reference to the plant’s sepals’ appearance.  The famous Swedish botanist/taxonomist Carl Linnaeus (L.) (1707-1778) gave the binomial name of Clematis crispa to swamp leather flower/blue jasmine. Many other common names are ascribed to this plant. The name virgin’s bower comes from the vine’s ability to cascade up and over objects creating a bower appearance and the light blue/white flower makes reference to virginity. Devil’s darning needle refers to the seed’s style or hooked end of the stamens. Old man’s beard, wild hops, devil’s hair, love vine, traveller’s joy, woodbine, bog clematis, small flowered clematis, vase vine, big sombrero, blue jasmine leather flower, swamp or marsh virgin’s bower, curly clematis, curled virgin’s bower, and lastly, flammula jovis (from severe skin reactions some people experience from coming into contact with this clematis) are other common names seen in literature. The two most used common names are swamp leather flower and blue jasmine. The former name is derived from the plant’s preferred habitat and for the thick leathered textured curly sepals. The latter name, blue jasmine, probably comes from the similar appearance to the yellow/Carolina jasmine (Gelsemium supervirens).

Clematis crispa has limited/documented medical usages as all the clematis species and their hybrids contain alkaloids as protanemonium (neurotoxin). All parts of this plant are potentially toxic to humans, cats, dogs, and horses if eaten, inhaled, or touched.  The severity of reaction is dependent on the amount of exposure and/or dosage and one’s reaction variability to the plant’s allergic/toxic properties.

Clematis plants are also very acridic (especially clematis crispa) and are extremely irritating to mucous membranes in the respiratory and gastrointestinal tracts.  Toxic effects include respiratory system irritation leading to coughing, mouth ulcers, blisters, extreme pain, profuse salivation, shortness of air, respiratory failure and death.  Adverse gastrointestinal effects include abdominal cramping, liver damage, severe diarrhea/vomiting leading to profound dehydration/electrolyte imbalance, severe bleeding, gastrointestinal ulcers resulting in death. Swamp leather flower can cause severe skin blisters, inflammations, and burns. Despite its toxicity, clematis species (including blue jasmine) are used in Europe/Asia. Most western cultures have banned its use in humans due to possible lethal side effects. Human deaths have been recorded in Eurasia from medicinal folklore usage of clematis extracts. Animal deaths are cited worldwide but rare as the acridity of clematis dissuades animal ingestion. Humans, particularly children, are also dissuaded from oral ingestion by clematis crispa’s acridity. The fact that it would require huge amounts of foliage to deliver enough toxins to cause death also lessens the possibility of severe side effects.

Reported medical usages of clematis include anticancer treatment, rheumatism, varicosities, debilitating headaches, syphilis, gonorrhea, gout, bone diseases, skin/wound conditions, fluid retention, poultices, diaphoresis, and as a stimulant. Clematis has been cited as one of the 38 plants used to prepare Bach flower remedies. Bach flower remedies are solutions of brandy and water containing extreme dilutions of flower material developed by Edward Bach, an English homeopath in the 1930’s. Cancer research UK, however, reports there is no scientific evidence that flower remedies can control, cure, or prevent any type of disease including cancers. Despite human and animal usages by Native Americans, no documentation exists to swamp leather flower’s validity or safety. In China, a clematis has been used for cancer and arthritis for 1000 years. Numerous medical organizations, however, warn that more evidence is needed to rate the effectiveness and safety of clematis species considering their potential lethal side effects. One should always consult with their doctor before initiating any medical usage of clematis specie. One interesting use in animals has clematis being a treatment for anxiety in dogs who demonstrate certain phobias! Clematis toxicity and acridity, especially in clematis crispa, has not created any documented culinary usages. Drying and/or cooking may only slightly decrease clematis toxicity and acridity.

Clematis crispa – swamp leather flower/blue jasmine’s real use is in its horticultural/ornamental usage as a perennial beautiful vine/ground cover. It gracefully twines readily up walls, trellises, fences, or poles. Blooming from early spring to early fall with its stunning purple/blue flowers makes it one of our prettiest long-lasting native wildflowers!

Clematis crispa’s nectar attracts ants, bees, wasps, flies, and butterflies. Swamp leather flower is also one of the main foods for the vividly green colored beetle called Lytta vesicatoria – a blister beetle better known as Spanish fly! Its seeds are food to birds and small mammals and its foliage provides significant nesting coverage for many song birds. Floragraphically in the lore of flower language, clematis species represents mental beauty. They also have the symbolic meaning of artfulness, artifice (cunning), love, ingenuity, soul mates, and good luck for women.

Clematis crispa can be grown from seeds or root cuttings, in ground or in pots. Plants left in pots, however, will not survive harsh winters. Contrary to popular folklore clematis plants, as C.crispa, do not like cool feet but rather thrive in moist soils – do not let C. crispa get too dry for too long. Clematis is resistant to salt and deer browse and it will tolerate hot and cold climates. Insects that are destructive to Clematis crispa include midges, leaf miners, flies, caterpillars, and aphids.
This summer, especially if visiting Hickman, Carlisle, or Fulton County wetlands, be on the lookout for this beautiful yet threatened Kentucky wildflower.

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