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Perennial Knawel

Scleranthus perennis

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Plant Profile

Flowering Months:
Caryophyllaceae (Pink)
Life Cycle:
Biennial or Perennial
Maximum Size:
15 centimetres tall
Fields, grassland, heathland, roadsides, rocky places, seaside.

Green, 5 petals
Dense clusters of green flowers. Flowers are about 5mm across. 10 stamens.
A long achene, 3 to 4mm in size.
A biennial or perennial flower with stems, woody at their bases. The stalkless, narrowly lance-shaped, pointed leaves are bluish-green, in opposite pairs along the stems. Needle-like.
Other Names:
Frequency (UK):
Rarely seen  

Similar Species

Other Information


Scleranthus perennis, commonly known as knawel or perennial knawel, is a species of flowering plant in the Caryophyllaceae family. It is native to Europe and Asia, but it has been introduced in many parts of the world. It is a low-growing, mat-forming perennial plant that produces small, inconspicuous, green or yellow flowers on short stems. The leaves are narrow, linear and scale-like, forming small rosettes. It prefers well-drained soils and full sun to partial shade to grow well. It is often used as a ground cover, in rock gardens, and in coastal gardens. It is tolerant of salt spray and can be used in landscaping in coastal regions. It is also drought-tolerant and can be grown in poor soils, making it a low-maintenance and versatile ground cover option.


Perennial Knawel, or Scleranthus perennis, is a fascinating plant that is known for its unique growth habit and ornamental value. It is a low-growing perennial that forms a dense mat of tiny, bright green leaves and small, inconspicuous flowers. Despite its diminutive size, Perennial Knawel has many interesting qualities that make it a valuable addition to any garden or landscape.

One of the most remarkable things about Perennial Knawel is its growth habit. Unlike most plants, which grow upright and reach for the sun, Perennial Knawel grows in a creeping, mat-forming pattern. Its stems are prostrate and can root at the nodes, allowing the plant to spread and form a dense, low-growing carpet. This makes it an excellent groundcover for rock gardens, pathways, and other areas where low-growing plants are desired.

Perennial Knawel is also notable for its hardiness and adaptability. It is native to Europe and Asia, but has been introduced to other parts of the world and has naturalized in many areas. It can grow in a wide range of soil types, from sandy to clayey, and is tolerant of drought, heat, and cold. This makes it an ideal plant for gardens and landscapes where other plants may struggle.

Another benefit of Perennial Knawel is its ornamental value. Its bright green foliage and delicate flowers make it a beautiful addition to any garden. The flowers are small and inconspicuous, but are produced in abundance and add a delicate, airy texture to the plant. Perennial Knawel is also useful in rock gardens and other naturalistic plantings, where its low-growing habit and fine texture can create a sense of depth and visual interest.

In addition to its ornamental value, Perennial Knawel also has some medicinal properties. It has been used in traditional medicine to treat a variety of ailments, including stomach and digestive issues, as well as to help reduce fever and inflammation. While these uses are not well-studied and should not be relied upon without consulting a healthcare professional, they do suggest that Perennial Knawel may have some beneficial qualities beyond its ornamental value.

Perennial Knawel belongs to the family Caryophyllaceae, which includes other popular garden plants such as carnations and pinks. It is a low-maintenance plant that requires little attention once established, making it an ideal choice for busy gardeners or those looking for a low-maintenance landscape.

Perennial Knawel can be propagated by seed or by stem cuttings. Seeds should be sown in the spring or fall, and stem cuttings can be taken in the summer. It is important to note that Perennial Knawel can be slow to establish from seed, so stem cuttings may be a more reliable method of propagation.

While Perennial Knawel is generally a hardy and easy-to-grow plant, it can be susceptible to root rot if grown in overly wet soil. It is important to ensure that the soil is well-draining and not too moist to prevent this problem. In addition, Perennial Knawel may be vulnerable to some pests and diseases, such as aphids and powdery mildew. Regular monitoring and proper care can help prevent these issues.

Perennial Knawel is also known by several other common names, including Knawel, German Knotweed, and Buttonweed. These names reflect the plant's historical use as a medicinal herb and its small, button-like flowers.

In addition to its ornamental and medicinal uses, Perennial Knawel has some ecological benefits as well. Its low-growing habit and dense mat of foliage can help prevent soil erosion and provide habitat for small animals and insects. It also has a low water requirement, making it a good choice for xeriscaping and other sustainable landscape practices.

One of the unique characteristics of Perennial Knawel is its ability to thrive in extreme environments, such as rocky or sandy soils, and its ability to withstand harsh weather conditions. This has made it an important plant for land reclamation and restoration projects, where it can help stabilize soil and prevent erosion in areas that have been disturbed by human activity or natural disasters.

Perennial Knawel has been used in traditional medicine for centuries to treat a range of ailments, including stomach and digestive issues, diarrhea, and fever. Its medicinal properties are thought to be due to the presence of various compounds, including tannins, flavonoids, and saponins.

In modern times, Perennial Knawel has also been studied for its potential as a natural remedy for certain health conditions. For example, research has suggested that it may have anti-inflammatory and antioxidant properties, which could make it useful for treating conditions such as arthritis and cardiovascular disease.

In addition, some studies have suggested that Perennial Knawel may have antimicrobial properties, which could make it useful for treating infections caused by bacteria and other microorganisms. However, more research is needed to fully understand the plant's medicinal properties and potential uses.

Despite its potential medicinal benefits, it is important to note that Perennial Knawel should not be used as a substitute for medical treatment or advice. As with any herbal remedy, it is important to consult a healthcare professional before using Perennial Knawel for medicinal purposes, especially if you have any underlying health conditions or are taking medications.

Overall, Perennial Knawel is a fascinating and useful plant that offers many benefits for gardeners, landscapers, and those interested in natural remedies. Whether you are interested in its ornamental value, its potential medicinal properties, or its ecological benefits, Perennial Knawel is definitely worth considering as a valuable addition to your landscape.

Distribution Map

Reproduced by kind permission of the BSBI.

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