Sunday, February 27, 2011

Solanum dulcamara - Bittersweet Nightshade

Solanum dulcamara - Bittersweet Nightshade, is a member of the Nightshade Family,  'Dulcamara' is a combination of Latin words meaning "sweet-bitter".  'Solanum' was derived from the same Latin root word as 'solace', and was likely given as a name because of this plant's many medicinal uses.  The name "bittersweet" is also used in some areas for some species in the genus Celastrus (also referred to as staff vines, family Celastraceae), e.g. American bittersweet (Celastrus scandens) and oriental bittersweet (Celastrus orbiculatus). 

Solanum dulcamara is also called Climbing Nightshade, Trailing Nightshade, Deadly Nightshade, Bitter Nightshade, Woody Nightshade, Bittersweet, European Bittersweet, Dulcamara, Felonwood, Felonwort, Fellenwort, Felon Bloom, Violet-bloom, Scarlet Berry, Snake Berry, Mortal, Poisonberry, Poisonflower, and Fever Twig, Blue Nightshade, Dogwood, Blue Bindweed.

Originally from Europe, it is now widespread throughout North America and commonly found in backyards, along edges of fields, vacant lands, roadsides, between hedges, and along streams and wetlands where it thrives in moist soil and partial shade.  It is usually propagated by birds who eat the berries and then drop the seeds.  It is a perennial vine or scrambling shrub with slender stems.  The lower stems are woody and the upper herbaceous branches die back each year. 

The flowers bloom from April to September, they grow in loose clusters, are star-shaped with five blue-violet (rarely white) petals that point backward and stamens that are fused in a prominent yellow cone; they grow along the branches on short stalks extending out from the stems.  Berries are oval or egg-shaped and bright red when ripe with numerous flat disk-shaped, light yellow seeds. The unripe berries are green.  Leaves are dark-green to purplish and often with one or two small ear-like lobes near the base, leaf blades are 1 to 4 inches long.  Main root grows horizontally just below the surface.  The crushed leaves and bark have an unpleasant smell.

Although bittersweet nightshade is not the same plant as deadly nightshade or belladonna, it is poisonous and has caused loss of livestock and pet poisoning and has caused death in children who accidentally picked the berries, probably because it was growing with blackberries. Bittersweet nightshade also has a strong, unpleasant odor so most animals will avoid it and poisonings from this plant are not very frequent.

The entire plant contains solanine, the same toxin found in green potatoes and other members of the nightshade family, and it also contains a glycoside called dulcamarine, similar in structure and effects to atropine, one of the toxins found in deadly nightshade. The toxin amount varies with soil, light, climate and growth stage. Ripe fruits are less toxic than the leaves and unripe berries but even ripe berries can be poisonous.

Although fatal human poisonings are rare, several cases have been documented.  Solanum dulcamara contains the toxin spirosolane glycoalkaloids.  Symptoms of spirosolane alkaloid poisoning include the following: circulatory and respiratory depression, convulsions, cyanosis, death, diarrhea, dilated pupils, headache, paralysis, scratchy throat, shock, speech difficulties, stomachache, subnormal temperature, vertigo, and vomiting. Adults appear to be relatively resistant to the toxicity of spirosolanes, but fatal intoxications are more common in children.

The leaves of Solanum dulcamara are considered moderately poisonous if ingested, and there is much disagreement over the toxicity of the berries. Some say that paralysis can result in humans that have eaten as few as 6 berries, other reports say 200 berries are needed to be toxic in adults. Cases of poisoning in cattle, horses, and sheep have been documented. Concentrations of toxic compounds within plants may vary with growth stage, and chemical components may vary from one individual to the next. Regardless, leaves and berries of the plant should be regarded as toxic.
Solanum dulcamara is used in naturopathy and herbalism almost exclusively for external problems. Its main use is for skin abrasions and inflammation. It is considered by some to be a herbal remedy for treating herpes and gout.   Combined with chamomile (Matricaria chamomilla)  it is said to make a good ointment for swellings, bruises, sprains, and corns. For skin diseases and sores, sources say to combine it with yellow dock  (Rumex crispus). 

Since the time of ancient Rome, nightshade has been used to treat a wide range of ailments. One such ailment, abscesses called "felons" on the fingertips, inspired one of the plant's common names, felonwort.  It was also used to treat asthma, bronchitis, jaundice, kidney problems, rheumatism, skin diseases, syphilis, and to counteract witchcraft.  Sepherds would hang it as a charm round the necks of their animals whom they suspected to be under the evil eye.  It was considered good for removing witchcraft in both men and animals, and to rid all sudden diseases whatsoever.  It was also considered a remedy for vertigo or dizziness when tied about the neck.


Pat said...

Thanks for posting this. I tried using two field guides - Venning-Saito and Tory Peterson - and neither one was any help. I posted a number of photographs on my blog Aberdeen NJ Life of plants along the Cliffwood Beach, NJ seawall. My bittersweet nightshade look much like yours. Nice site!

mst64 said...

Beautiful plant, beautiful site. I have enjoyed reading through it.

Toni McG said...

Thanks for this lovely page! It has helped me identify this plant in my yard. Now the question is whether or not to pull it out (I have 3 dogs that could potentially get to it) or leave it as is. Decisions...