Solanum nigrum

Scientific Name	Solanum nigrum L.
Common Names	English: Black Nightshade; German: Schwarzer Nachtschatten; French: Morelle noire; Spanish: Hierba mora
Description	Annual seed-propagated weed, up to 50 cm (19.68 inch) tall with a short, cone-shaped root. The whole plant is loosely or closely hairy and originates from North America.

Characteristic Features

Bushy, branching growing habit.
Round, pea-sized, blue-black fruits.

Young Plant

Cotyledons stemmed, dark green, smooth-edged, oval, coming to a narrow point. Distinct midrib, sparsely haired.

Cotyledons

Stemmed, dark green, smooth-edged, oval, coming to a narrow point; distinct midrib.

Stems

Prostrate to ascending, ramified, sparsely short-haired, weakly violet like the leaf petiole, up to 50 cm (19.68 inch) high.

Leaves

Ovate to rhomboid, sinuately dentate or entire margin, sparsely haired, petiolate, dull dark green, alternate.

Flowers

White with five lobes in a star-shape.
Clusters of several flowers on short stems (cyme).

Flowering Period

Summer - autumn.

Fruit

Bluish-black berry with many seeds.

Seeds

Germination in late spring. Seeds have an irregular oval in shape, brownish-yellow, finely pitted. S. nigrum germinates especially at a depth of 0.5-1 cm (0.19 - 0.39 inch).

Viability of Seeds

> 40 years.

Propagation

Approx. 500 seeds/plant.

Habitat

Waste land, old fields, ditches, and roadsides, fence rows, or edges of woods and cultivated land.

Soil

S. nigrum likes humus-rich, nitrogen-rich, friable soils, is a nitrogen indicator and poisonous.

Agricultural Importance

Black Nightshade is a warmth-loving late germinator which grows quickly in emerged root crops. The long viability of seeds leads to heavy weed infestations. As a late-season weed, it is a serious competitor for water and nutrients. It interferes with harvesting and causes problems with silage production (solanidine). S. nigrum often escapes weed control because of late emergence after application of herbicides; the whole plant is poisonous and can significantly decrease the quality of vegetables such as spinach, edible beans and soybeans. Triazine- and ALS resistant biotypes have been identified.

Useful non-chemical contribution to Integrated Weed Management

Control of late emerging seedling by dense crops and rotations with winter annual crops.