Ontario Weeds: Teasel
Excerpt from Publication 505, Ontario Weeds,
Order this publication
Table of Contents
- Other Names
- General Description
- Stems and Roots
- Flowers and Fruit
- Similar Species
- Related Links
Teasel (A - plant before flowering; B - mature seed heads).
Teasel. A. First-year plant with rosette leaves.
B. Top of flowering branch.
Stems & Roots: First-year plants
becoming large rosettes, the leaves long, tapering towards both
ends, somewhat toothed along the margins, with scattered, stout
prickles on the upper surface, especially along the midrib and with
each side vein curving forward and joining the next vein above it;
stems of second-year plants erect, to 2m (6½ft) high, usually
branched near the top, very prickly; stem leaves similar to rosette
leaves but smaller, stalkless, broader towards the stem and tapering
towards the tip, opposite (2 per node), their bases occasionally
united and forming a cup around the stem which may hold a quantity
Flowers & Fruit: Flowers in egg-shaped, dense, spiny heads with long, slender, stiff, prickly bracts below the head and numerous, short, stiff bristles within the head; individual flowers small, corolla tubular, 10-15mm (2/5-3/5in.) long, whitish near their bases, pale to deep purplish towards their 4-lobed ends, 3-4mm (1/8-1/6in.) across, with usually 4 stamens protruding from the corolla tube; flower heads maturing into hard, brown, stiff-spined structures that were used for teasing and carding wool (hence the common name); seeds 4-angled, ridged, light brown, about 5mm (1/5in.) long. Flowers from July to September.
Habitat: Teasel occurs throughout southern Ontario in waste areas, meadows, roadsides, and sometimes in cultivated land, usually in moist areas and on coarse soils.
Similar Species: It is distinguished by its large rosette of shiny green leaves with stout prickles on the upper surface, its prickly stems with pairs of opposite leaves often having cup-like bases, its egg-shaped heads of flowers at the ends of stems and branches, these maturing into hard, brown structures completely surrounded by firm, sharp bristles.
For more information:
Toll Free: 1-877-424-1300