Where in the OLL?

• S. dulcamara is NOT native to the Americas. Its native range is widespread in Europe, Eastern Asia and Northern Africa. This plant has been included due to its current presence in the Wetlands Meadow in the OLL. It belongs to the Solanum genus of the Nightshade family, along with well-known and loved members such as potato (Solanum tuberosum), tomato (Solanum lycopersicum), and eggplant (Solanum melongena).
• Solanine (glycoalkaloid poison) is produced by plants of the Solanum genus. It is produced as the plant’s natural defense against insects, diseases and herbivores. Solanine can be found in greening potatoes (S. tuberosum), which increases with light exposure. Although the green color itself is just harmless chlorophyll, the presence of green indicates solanine build-up underneath the skin. 
• IMPORTANT NOTE: All parts of S. dulcamara are toxic; the highest concentration is found in green, unripe berries. Although fatal solanine poisoning cases are rare in humans, there are documented cases of fatalities in children from the ingestion of S. dulcamara. It is neurotoxic, causing neurological and gastrointestinal illnesses. It contains both solanine and dulcamarine. Dulcamarine is similar to atropine, one of the toxins found in deadly belladonna plant (Atropa belladonna). Solanine can inhibit cholinesterase, which acts as a neurotransmitter and reactions are necessary for certain neurons to return to resting state. Research shows solanine exposure opens the potassium channels of mitochondria. This increases its membrane potential and can lead to increased calcium concentration in the cytoplasm, causing cell damage and apoptosis (cell death). Although the plant looks pretty, it shouldn’t be consumed.
• INVASIVE OR NOT?
• Solanum dulcamara has been documented in the United States for hundreds of years. It is an introduced and naturalized species. Surveys indicate that S. dulcamara was documented as widespread in the U.S. by the early 20th century. In many plant communities, it is only a minor component, but it can become invasive in certain conditions. Bill Clinton’s Executive Order 13112 (1999) led many states including Connecticut to form an invasive plants council to advise state lawmakers. Connecticut General Statutes §22a-381d classifies S. dulcamara as a noxious weed/potentially invasive and bans importing, moving, selling, purchasing, transplanting, cultivating or distributing it. This may indicate some New England ecosystems could be vulnerable to S. dulcamara becoming invasive. Tolerant of varying soil and light conditions, it can form monocultures by scrambling over other plants for its structure, effectively shading out important native plant life. It is notable in wetland ecosystems, where  S. dulcamara may even thrive in standing water, and can cause problems with hydrology. Because wetland ecosystems are so important to climate health overall, presence of climbing nightshade could potentially prove harmful. S. dulcamara should be monitored in the OLL in spring and summer to ensure it is not becoming invasive, or co-opting spaces intended for native plant life.

Plant growth form

• vine or scrambling shrub with woody base
• perennial: woody base persists over winter and herbaceous branches die back
• roots of climbing nightshade have an epidermis that is protected by a layer of suberin (a hydrophobic biopolymer found in plants) at root cap
• rhizomatous – it has modified underground stems system can set roots and shoots
• seeds are very flattened in appearance
• also reproduces via vegetative regeneration – it will root at nodes and sprout from base when cut or damaged
• leaves vary from about 2-5 inches long
• leaves alternately arranged with distinct petioles
• terminal lobe of leaves is much larger than the 2 opposite lobes at the base and has an acute apex
• leaf base can be cordate, hastate, or truncate in shape

Flowers, fruits & pollinators

• perfect flowers
• blue-violet to purple
• 5 panicled, star-shaped petals reflex (bend backwards) as they open
• petals unite at base
• each petal has two shiny basal spots
• bloom approx. May-September in New England
• although larger and blue/purple in color, they are comparable in appearance to tomato flowers
• 10-25 flowers in each inflorescence – meaning group or clusters of flowers on stem
• flowers are arranged in reflexed, drooping cymes positioned opposite leaves
• 5 sepals, 5 petals, 1 pistil 5, stamens
• fused carpels, petals and sepals are fused into a cup or tube
• sepals are fused to each other (not other flower parts) near their bases
• yellow anthers are fused and emerge at the center of the flower
• pistil protrudes from fused stamens
• stamens have short filaments and lance-shaped anthers which closely hug the style 

Ideal location, conditions & cultural needs

• tolerant of varying light conditions, prefers more sunlight
• pH ranges from above 4 to levels as high as 7.9 to 9
• tolerant of low-nutrient soil, alka-tolerant – will grow in calcareous soil (high pH)
• tolerant to both flooding and drought/fire due to rhizomes
• often noted in ecosystems with ongoing disturbances
• recorded growing in over 1.5 ft standing water in MA

Range:

• circumpolar distribution
• distributed throughout most of the US with much fewer in southernmost states
• significant communities occur in New England, Mid-atlantic, Great Lakes and Pacific NW
• typically found in wetlands, riparian and deciduous areas
• significant populations in anthropogenic habitats

Planning & maintenance

• difficult to manage, especially once established, due to rhizomes and vegetative regeneration
• it is known to be cultivated as an ornamental,  but they are not ideal ornamentals due to toxicity
• above ground stems can reach 10-23 ft in length
• 11.8-59 inches in height
• branches may grow and die back 3-6 ft each year
• can scramble/twine over other plants for structure or stand on its own
• if invasive, attempt removal without the use of herbicides

Recommended removal: careful manual removal of all roots before rhizome growth is extensive, continue checking and removing throughout early season. Prevent regrowth by planting native species and mulching/covering the site of S. dulcamara roots.

• garden tools (hand-cultivator, hoe, rake, shovel, spade) may be required if removing from  a wet area, optimal time to remove is when soil is moist but not flooded, using caution as to not to cause unnecessary disturbance
•  avoid removal of native or beneficial plant roots, such as in cases where roots are growing between rocks
• gloves, long socks and pants should be worn during handling to prevent skin irritation
• do not compost or dump root balls, berries or flowers or stems after removal to avoid further spreading
• mowing is not a sustainable method of removal, it must be done periodically throughout the season due to suckering roots and rhizomes, and leads to disturbance and erosion

Cultivars & propagation

• should not be deliberately cultivated as an ornamental, solanine has caused illness in pets, livestock and humans
• this plant is NOT native to MA

Pests & pathogens

Diseases or pests pertinent to the Solanaceae family including (but not limited to):

• Colorado potato beetle (feeds entirely on the Solanaceae family)
• May be host plant to several species of thrips
• Manduca sexta (tobacco hornworm as larva, tobacco hawk moth as adult)
• Manduca quinquemaculata (tomato hornworm as larva, five-spotted hawk moth as adult)
• Early/late blight
• Phthorimaea operculella (tobacco splitworm as larva, potato tuber moth as adult)
• Potatoes irrigated with water cross contaminated with Solanum dulcamara (such as on water banks) infected with Ralstonia solanacearum (brown rot) can transmit the bacterium to potato crop according to study in UK
• Beet pseudo-yellow virus (BPYV)
• Dulcamara mottle virus (DMV) transmitted by Psylliodes affinis (potato flea beetle)
• One study has documented S. dulcamara responding to Spodoptera exigua (beet armyworm as larva, small mottled willow moth as adult) eggs by producing hydrogen peroxide as ovicide at the site
• Arbuscular mycorrhizal fungi (AMF) has been studied with S. dulcamara, showing it communicates an “emergency” to the plant, prompting the plant to produce chemical defenses against herbivores

Landscape & ecosystem

• beautiful blue/violet flowers and berries are vibrant orange to red as they ripen – colorful landscape                              
• crows, Eastern kingbirds, Mimic-thrushes, Thrushes, White-crowned sparrow, Waxwings, Ring-necked pheasants eat the berries
• in the UK, fruit is the primary food for Blackcaps, also used by Blackbirds, Song thrush, Robin, Starling, and Spotted flycatcher.
• bullfinches only known bird to eat climbing nightshade fruit for its seed
• gray catbirds in the central portions of North America and Ontario occasionally use S. dulcamara for nest building
• American eiders nesting along Maine’s Penobscot Bay occasionally used S. dulcamara twigs for nest building, but with lower nesting/hatching success than in nests constructed with native vegetation

Human uses

Although nonnative to N. America, ethnobotany records document many indigenous groups using S. dulcamara plant parts for medicinal remedy for a variety of ailments:

• Iroquois (biliousness)
• Delaware (root for fever, salve)
• Mimac (nausea)
• Malecite (nausea)
• Nootka (‘derangement’ of stomach and bowels)
• Many EU member countries permit sale of tea, capsules, ointments and extracts as plant medicinal products for acne, eczema, dermatitis and stomach complaints
• Extracts of S. dulcamara have shown inhibitive effect on staph and E. coli in some studies (extracted in labs, do not attempt at home!)