Ontario Weeds: Eastern black nightshade
Excerpt from Publication 505, Ontario Weeds,
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Table of Contents
- Scientific name
- Other names
- General description
- Flowers and fruit
- Roots and underground structures
- Often confused with / Distinguishing features
- Herbicide resistance
- Related links
- Solanum ptycanthum Dun.
- morelle noire de l'est, Black nightshade, Deadly nightshade, SOLPT
- Nightshade or Potato Family (Solanaceae)
- Eastern black nightshade is an annual reproducing only by seed.
- Eastern black nightshade occurs throughout southern Ontario in open dry woods, edges of pastures, waste places, and in cultivated land, especially in row crops.
- 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 erect, 5-100 cm (2-40 in.) high
Very branched in the upper part of the stem
- Alternate (1 per node)
- Oval or diamond shaped
- Pale green, soft and nearly translucent
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 9-15 mm 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.
Sulphonylurea and imidazolinone resistant (WSSA group 2) populations exist in Ontario.
Figure 1: Eastern black nightshade seedling at the 2-leaf stage
Figure 2: Eastern black nightshade leaf
Figure 3: Eastern black nightshade flower
Figure 4: Immature green fruit of Eastern black nightshade that will turn black at maturity
Figure 5: Mature Eastern black nightshade
... on general Weed
... on weed identification, order OMAF and MRA Publication 505: Ontario Weeds
... on weed control, order OMAF and MRA Publication 75: Guide To Weed Control
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