Who has not stepped on a thistle in their bare feet? When we preferred going in our bare feet rather than wear shoes, some part of every day was spent removing the needle-like spines of thistles from the soles of our feet. The dried leaves of the many thistles would pierce our skin with regularity. The operation was usually accompanied by many 'ouches', especially early in the summer, before the skin on the soles of our feet had toughened up.
Thistles are a group of plants well known because of their spiny leaves and large flower heads of purple or, in one species, yellow. Most forms of the species are biennials that form rosettes of prickly leaves that overwinter the first year.
Thistles are generally divided into two groups, those that have spines on the stems and those without. One of the most common variety is the Canada thistle, an import from Europe and not home-grown. Thistle seeds arrived on this side of the ocean among grains that were planted as food crops. These seeds grew with abandon and before long outnumbered our native species. Along the way, new varieties were established and today there are several types growing in most locales. The seeds have tufts of hair that provide buoyancy so they can be spread on the wind over long distances. Thistle seed is a common food for many small mammals and birds, especially the finches.
In its native Europe it was known as creeping thistle because it sprang from creeping roots. The branching stem has many unstalked leaves that are deeply lobed and feature many rigid spine-tipped teeth. The purple flower heads are surrounded by spine-tipped bracts.
The bull thistle is a common thistle and a very prickly customer. Its stem is covered with sharp spines and the leaves have several long, sharp spines that pierce the skin upon contact. The large purple flowers have rigid yellow-tipped spines on the flower bracts; the leaves are pale and woolly underneath. This thistle grows up to 1.5 meters (5 feet) high.
The Scotch thistle is another prickly contender. The stalk is covered with very heavy triangular spines along its entire length. The leaves are fitted with sharp spines as well. The solitary flower head is pale purple with spreading yellow spines.
The swamp thistle is our tallest thistle: one to three meters (three to nine feet) tall. It grows in wet areas suitable for sustaining its rapid growth. The flower heads are two to three centimetres (one to two inches) wide and purple to rose-purple in colour.
Thistles are a common sight in most parts of Canada. Their purple flowers turn white as the seeds develop. With a puff of wind they scatter to settle on new ground to begin another life cycle.
Photos by Clayton Rollins
Thistles are a group of plants well known because of their spiny leaves and large flower heads of purple or, in one species, yellow. Most forms of the species are biennials that form rosettes of prickly leaves that overwinter the first year.
Thistles are generally divided into two groups, those that have spines on the stems and those without. One of the most common variety is the Canada thistle, an import from Europe and not home-grown. Thistle seeds arrived on this side of the ocean among grains that were planted as food crops. These seeds grew with abandon and before long outnumbered our native species. Along the way, new varieties were established and today there are several types growing in most locales. The seeds have tufts of hair that provide buoyancy so they can be spread on the wind over long distances. Thistle seed is a common food for many small mammals and birds, especially the finches.
In its native Europe it was known as creeping thistle because it sprang from creeping roots. The branching stem has many unstalked leaves that are deeply lobed and feature many rigid spine-tipped teeth. The purple flower heads are surrounded by spine-tipped bracts.
The bull thistle is a common thistle and a very prickly customer. Its stem is covered with sharp spines and the leaves have several long, sharp spines that pierce the skin upon contact. The large purple flowers have rigid yellow-tipped spines on the flower bracts; the leaves are pale and woolly underneath. This thistle grows up to 1.5 meters (5 feet) high.
The Scotch thistle is another prickly contender. The stalk is covered with very heavy triangular spines along its entire length. The leaves are fitted with sharp spines as well. The solitary flower head is pale purple with spreading yellow spines.
The swamp thistle is our tallest thistle: one to three meters (three to nine feet) tall. It grows in wet areas suitable for sustaining its rapid growth. The flower heads are two to three centimetres (one to two inches) wide and purple to rose-purple in colour.
Thistles are a common sight in most parts of Canada. Their purple flowers turn white as the seeds develop. With a puff of wind they scatter to settle on new ground to begin another life cycle.
Photos by Clayton Rollins
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