Plant Description

The creeping thistle is a patch-forming, herbaceous, rhizomatous creeping perennial plant that grows about 1 to 6.5 feet (0.3-2 m) tall. The plant is found growing in both disturbed (tilled) and no-tillage agricultural fields, arable land, roadsides, cultivated land, stream banks, ditches, lakeshores, seashores, sand dunes, other open sandy areas, in clear cuts and forest openings, wet-mesic grasslands, prairie potholes, overgrazed pastures, meadows, fence rows, campgrounds, road building, and pasture. The plant grows on all waterlogged, poorly aerated, and peat soils, including clay, clay loam, silt loam, sandy loam, sandy clay, sand dunes, gravel, limestone, and chalk. It also grows best on limestone soils with abundant moisture.

Creeping Thistle facts

Root and Stem

The plant has a deep and wide-spreading root system with a slender taproot and far-creeping lateral roots. It often forms large patches, and individual clones may reach 115 feet (35 m) in diameter. Most Canada thistle roots are in the top 0.7 to 2 feet (0.2-0.6 m) of soil, but roots can extend as deep as 6.5 to 22 feet (2-6.75 m). Stems are 30–150 cm, slender green, and freely branched, smooth and glabrous (having no trichomes or glaucousness), mostly without spiny wings.

Leaves

Leaves are alternate on the stem with their base sessile and clasping or shortly decurrent. The leaves are very spiny, lobed, and up to 15–20 cm long and 2–3 cm broad (smaller on the upper part of the flower stem). They are dark green and lanceolate to oblong-lanceolate. They are glabrous above, but their undersides have short, white hairs. They may be pinnatifid and very prickly. Basal leaves are 5-8 in. (12-20 cm) long. Leaf characteristics are variable across different varieties and subspecies.

Flower

The inflorescence is 10–22 mm (0.39–0.87 in) in diameter, pink-purple, with all the florets of similar form (no division into disc and ray florets). The plants are polygamo-dioecious, thus there are male and female plants. The female inflorescences are flask-shaped, 1-1.5 cm (0.4-0.6 in.) in diameter, and 1-2 cm (0.4-0.75 in.) tall. The female flowers have a fragrance, while the male flowers do not. The male flowers are more globose in shape than the female flowers and are smaller. The flowers are usually purple in color, but can be pink or white. The plant is in bloom from June to August.

Fruit

The fruits (achenes) are tiny, 2-3 mm (0.1 in.) long and about 1 mm (0.04 in.) in diameter, and have a white to light brown pappus attached. Seeds are 4–5 mm long, with a feathery pappus which assists in wind dispersal. One to 5 flower heads occur per branch, with plants in very favorable conditions producing up to 100 heads per shoot. Each head contains an average of 100 florets. Average seed production per plant has been estimated at 1530. More seeds are produced when male and female plants are closer together, as flowers are primarily insect-pollinated.

Traditional uses and benefits of Creeping Thistle

• Root is tonic, diuretic, astringent, anti-phlogistic and hepatic.
• It has been chewed as a remedy for toothache.
• Decoction of the roots has been used to treat worms in children.
• Paste of the roots, combined with an equal quantity of the root paste of Amaranthus spinosus, is used in the treatment of indigestion?.
• The plant consists of a volatile alkaloid and a glycoside called niacin, which has emetic and emmenagogue properties.
• Leaves are anti-phlogistic.
• They cause inflammation? and have irritating properties.
• Common thistle roots have also been used as a poultice and a decoction prepared using the plant too is used as a poultice to treat aching jaws.
• A hot infusion prepared with the whole common thistle plant has been traditionally used to treat rheumatic joint pains.
• Decoction prepared with the whole plant has been used internally as well as externally to heal bleeding piles?.

Culinary Uses

• Root of first-year plants can be consumed raw or cooked.
• Nutritious but rather bland, they are best used in a mixture with other vegetables.
• Stems are peeled and cooked like asparagus or rhubarb.
• Leaves can be consumed raw or cooked.
• It has a fairly bland flavor, but the prickles need to be removed before the leaves can be eaten.
• Leaves are also used to coagulate plant bowls of milk etc

References