Tanacetum

Tansy

Tanacetum corymbosum4 W

Tanacetum balsamita 02

Tanacetumcamphoratum1

Tanacetum cinerariifolium - Köhler–s Medizinal-Pflanzen-269

Tanacetum coccineum - Köhler–s Medizinal-Pflanzen-037

Tanacetum is a genus of flowering plants in the Asteraceae family, which is commonly known as the daisy, composite, or aster family. This genus is distributed widely across Europe, Asia, and North Africa, with a few species extending into North America. Tanacetum includes a variety of species, some of which are well-known for their uses in horticulture, medicine, and as insecticides. The most recognized species within this genus include Tanacetum parthenium (feverfew), Tanacetum vulgare (tansy), and Tanacetum cinerariifolium (pyrethrum).

Description

Plants within the Tanacetum genus are perennial herbs or shrubs. They typically have alternate, sometimes dissected leaves and are aromatic. The flowers can be yellow, white, or pink and are usually arranged in dense inflorescences. Each flower head is composed of florets, with the outer florets often being ray florets and the inner ones being disc florets, a characteristic feature of the Asteraceae family.

Taxonomy

The taxonomy of Tanacetum has been complex and subject to revision. It was previously included in the genus Chrysanthemum but has been separated based on molecular data. The genus is divided into several sections based on morphological and genetic data, which help in distinguishing between the closely related species.

Ecology

Tanacetum species are found in a variety of habitats, from sunny, open fields to rocky cliffs. They are adapted to a range of environmental conditions and can be found at various altitudes. These plants are pollinated by insects (entomophily), including bees, butterflies, and other insects attracted by their flowers. Some species of Tanacetum are known to be invasive in parts of North America.

Uses

Medicinal

Several species of Tanacetum have been used in traditional medicine. Tanacetum parthenium is used for migraine prevention and treatment of fevers, while Tanacetum vulgare has been used for its anthelmintic properties. The essential oils derived from some Tanacetum species have anti-inflammatory and insecticidal properties.

Horticultural

Tanacetum species are popular in gardens for their attractive flowers and foliage. They are used in borders, herb gardens, and as cut flowers. Their ability to repel certain insects makes them beneficial companion plants in gardens.

Insecticidal

Tanacetum cinerariifolium is the source of pyrethrin, a natural insecticide. Pyrethrin is extracted from the dried flower heads and is used to control pests in organic farming and household insecticides.

Conservation

While many Tanacetum species are common and not considered at risk, habitat destruction and overharvesting for medicinal and horticultural use have led to declines in some populations. Conservation efforts are needed for species with limited distributions and those that are heavily exploited.