Ontario Weeds: Purple cockle
Excerpt from Publication 505, Ontario Weeds,
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Table of Contents
- Other Names
- General Description
- Stems and Roots
- Flowers and Fruit
- Similar Species
- Related Links
Name: Purple cockle, Agrostemma githago
Other Names: Corn cockle, nielle, nielle des blés, nielle des champs
Family: Pink Family (Caryophyllaceae)
General Description: Annual or sometimes biennial, reproducing only by seed.
Stems & Roots: Stems - erect,
30-120cm (1-4ft.) high, hairy, with swollen nodes;
Leaves: Opposite (2 per node), stalkless, linear to lance shaped, 5-13cm (2-5in.) long, narrow and silky hairy;
Flowers & Fruit: Flowers large, showy purple or purplish-red on long stalks, the 5 green sepals united for 1/3 to ½ their length forming a calyx tube 12-18mm (½-¾in.) long; the calyx lobes (sepal tips) 2-4cm (4/5-1½in.) long, narrow and projecting between and past the petals; petals 5, large, spreading, purple or purplish-red with black spots; as the seedpod expands inside the calyx tube, it emphasizes the 10 prominent, hairy green, lengthwise ribs on the calyx tube; the mature seedpod inside the calyx being smooth, hairless and orange-brown, and opening with 4 or usually 5 teeth at the top; seeds purplish-black, rounded-angular, about 3mm (1/8in.) across and densely covered with tiny, sharp bumps. Flowers from June to September.
Habitat: Purple cockle was a very common weed in southern Ontario in the days of horse-drawn farm implements but, with the change in farming techniques, it has largely disappeared. However, it still occurs sporadically in cultivated fields, especially in fall-sown crops such as wheat and rye, in the central and western parts of southern Ontario.
Similar Species: It is distinguished by its silky hairy stems with opposite, long, narrow leaves, large purple flowers and large purplish-black seeds.
Caution: Though rare, it is important because its seeds are poisonous to livestock and fowl so it should be eliminated from feed grain.
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