eastern black nightshade
Scientific Name: Solanum ptycanthum Dun.
Other names: morelle noire de l’est, Black nightshade, Deadly nightshade, SOLPT
Family: Nightshade or Potato Family (Solanaceae)
General Description: Eastern black nightshade is an annual reproducing only by seed.
Habitat: Eastern black nightshade occurs throughout southern Ontario in open dry woods, edges of pastures, waste places, and in cultivated land, especially in row crops.
Seedlings
- Hypocotyl (stem below cotyledon) are hairy and can be green or maroon
- Cotyledon is oval, smooth and green on the upper surface, maroon on lower surface
Stems
- Stems erect, 5-100 cm (2-40 in.) high
- Very branched in the upper part of the stem
- mostly hairless
Leaves
- Alternate (1 per node)
- Oval or diamond shaped
- Pale green, soft and nearly translucent
Flowers and Fruit
- Flowers are small and usually grouped together in a small umbel of 2 to 5 flowers
- Flowers extend from a short stalk from the side of the stem
- Petals are white and may or may not be tinged with purple
- Resemble potato flowers but are smaller at 9-15mm in diameter
- Fruits are black berries that are first green and contain many flat seeds
- Berries are reputed to be poisonous
- Flowers from June until late autumn
Roots and Underground Structures
Eastern black nightshade has a slender taproot with branched fibrous root system.
Often Confused With / Distinguishing Features
It is often mistaken for pigweed seedlings. Eastern black nightshade is distinguished from other weeds as it is an annual plant that has thin, oval to diamond shaped leaves, small umbels of white flowers on the side of stems and black berries when mature.
Herbicide Resistance
Sulphonylurea and imidazolinone resistant (WSSA group 2) populations exist in Ontario.
References
http://www.weedinfo.ca/en/weed-index/view/id/SOLPT
http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/eblack_nightshade.htm
Click to enlarge.
