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Bastard Toadflax

Thesium humifusum

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Plant Profile

Flowering Months:
Santalaceae (Sandalwood)
Also in this family:
Life Cycle:
Maximum Size:
20 centimetres tall
Gardens, grassland, rocky places.

White, 5 petals
The inflorescence is a flower spike. The flowers are yellowish-green but white on the outside. Star-shaped with 5 conjoined petals. Flowers each measure 2 or 3mm across. Leaf-like bracts are present near their bases.
The fruit is a nut.
Bastard Toadflax is a semi-parasitic perennial whose foliage is difficult to notice among the grasses in which it usually grows. It's leaves are narrow and linear. The leaves are alternate along both sides of the stems. Mat-forming. Normally found on short turf.
Other Names:
Creeping Thesium.
Frequency (UK):

Other Information


Thesium humifusum is a species of flowering plant in the family Santalaceae. It is native to Europe and can be found in grassland habitats, on rocky or sandy soils, and also often on calcareous soils. The plant is a perennial herb that has thin, creeping stems and small, narrow leaves. It produces small, greenish-yellow flowers in the summer. It is relatively rare in some regions and is protected by law in some countries. It is also known as creeping thesium. It is often used as ground cover or in rock gardens.


Bastard Toadflax, also known as Thesium humifusum, is a plant species native to the European regions, including the Mediterranean and parts of Asia. It is a member of the Santalaceae family, which is a group of parasitic plants that are commonly known as mistletoes. However, unlike mistletoes, Thesium humifusum is not a true parasite and can grow independently.

Thesium humifusum is a low-growing herbaceous plant, typically reaching a height of only 10-20 cm. It has thin, wiry stems that bear a striking resemblance to toadflax, hence its common name. The leaves of the plant are small and linear, with a green to gray-green color. The flowers are small, yellow, and grow in clusters, which makes the plant highly ornamental.

One of the most distinctive characteristics of Thesium humifusum is its growth habit. Unlike most plants, it does not have an extensive root system. Instead, it develops a taproot that is capable of reaching deep into the soil to absorb water and nutrients. This adaptation allows the plant to grow in difficult soil conditions, such as rocky or dry soils.

Thesium humifusum has been used for medicinal purposes for centuries. In traditional medicine, it was believed to have a range of medicinal properties, including diuretic, anti-inflammatory, and sedative effects. The plant has been used to treat conditions such as kidney problems, urinary tract infections, and digestive problems. However, there is limited scientific evidence to support these claims, and further research is needed to determine the true medicinal properties of the plant.

Despite its ornamental appearance and potential medicinal benefits, Thesium humifusum is not widely cultivated. This is due to its limited distribution, as well as its slow growth rate. However, for those who are interested in growing this plant, it is best grown in a sunny location in well-draining soil. The plant is low-maintenance and is resistant to pests and diseases, making it an ideal choice for gardeners who are looking for a unique and attractive plant.

Thesium humifusum, or Bastard Toadflax, is a fascinating plant species that has a rich history of traditional use and ornamental value. Despite its limited cultivation, it is a plant worth considering for those who are looking for a unique and low-maintenance addition to their garden. Whether for its ornamental beauty or its potential medicinal properties, Thesium humifusum is definitely a plant worth exploring.

In addition to its ornamental and medicinal uses, Thesium humifusum also has ecological significance. As a native species, it plays an important role in maintaining the balance of the ecosystem in which it grows. The plant provides food and habitat for a variety of insects, including bees, butterflies, and other pollinators. Additionally, its deep root system helps to prevent soil erosion, which is important for maintaining healthy soil and protecting against soil degradation.

Another interesting aspect of Thesium humifusum is its relationship with mycorrhizal fungi. Mycorrhizal fungi are a type of fungus that form symbiotic relationships with plants, providing the plant with essential nutrients in exchange for carbohydrates produced through photosynthesis. This relationship is crucial for the survival of Thesium humifusum, as it allows the plant to grow in nutrient-poor soils and to absorb essential nutrients more efficiently.

Despite its importance, Thesium humifusum is considered a threatened species in many parts of its native range, due to habitat destruction and degradation. It is important to protect and conserve this species, as well as its habitat, to ensure its survival and to prevent it from becoming extinct. This can be achieved through measures such as habitat restoration, conservation and protection of remaining populations, and increased public awareness about the importance of this plant.

Thesium humifusum is a fascinating and important plant species that deserves more recognition and protection. From its ornamental beauty, potential medicinal properties, ecological significance, and relationship with mycorrhizal fungi, there are many reasons why this plant is worth exploring. Whether you are a gardener, a conservationist, or simply someone who appreciates the natural world, Thesium humifusum is a plant that should not be overlooked.

In addition to its importance as a native species, Thesium humifusum also has cultural significance. For example, in some parts of its native range, it has been used in folk medicine for centuries and is still used today as a traditional remedy for various ailments. Additionally, the plant has been used in religious and cultural rituals, with some cultures using it as an offering to their gods or as a symbol of good luck and prosperity.

In horticulture, Thesium humifusum can be a valuable addition to rock gardens, herb gardens, or wildflower meadows. Its low-growing habit and attractive yellow flowers make it a great choice for ground cover, and its tolerance of difficult growing conditions makes it an ideal choice for gardeners who are looking for a low-maintenance plant.

However, it is important to note that while Thesium humifusum is generally considered a hardy plant, it is not suitable for all gardeners. For example, it is not a good choice for those who live in areas with high rainfall, as it prefers a dry and sunny environment. Additionally, its slow growth rate may not be suitable for gardeners who are looking for fast-growing plants.

Despite these limitations, Thesium humifusum is a valuable and unique plant species that is worth considering for those who are looking for an ornamental, low-maintenance, and culturally significant plant. Whether you are interested in its ornamental beauty, potential medicinal properties, cultural significance, or ecological importance, Thesium humifusum is a plant that is definitely worth exploring.

In conclusion, Thesium humifusum, or Bastard Toadflax, is a fascinating plant species that has a rich history, cultural significance, and important role in the ecosystem. Whether you are a gardener, a conservationist, or simply someone who appreciates the natural world, Thesium humifusum is a plant that should not be overlooked. With its unique characteristics, attractive appearance, and potential for ecological and cultural benefits, this plant is definitely worth considering for any garden or landscape.

Distribution Map

Reproduced by kind permission of the BSBI.

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