Echinacea angustifolia (narrow-leaved purple coneflower)

Echinacea angustifolia occurs in open, dry areas throughout the North American tallgrass prairie west of the Mississippi River. It ranges from the southern state of Texas to the southern part of Canada.

Coneflowers (Echinacea sp.) are one of 12 star plants featured in this year’s North American Landscape - the fifth in the series created by Kew for the British Museum’s West Lawn.

North American plants have global ecological and economic importance and have been utilised by native peoples for thousands of years. Many were introduced to Europe following the colonisation of North America in the early 1600s. Grown for their medicinal uses, as food crops and for other economic purposes, some species have also become familiar ornamental garden plants.

The landscape has been designed to evolve throughout the seasons - from a carpet of colourful daisies in the summer to spectacular orange and red maple leaves in the autumn. Other plantings include cypress, echinacea and carnivorous pitcher plants.

Open 10 May – 25 November

- Visit the North American Landscape

- Keep up to date by following the Kew at the British Museum blog

- Discover all 12 star plants in the Landscape

A close up of a flowering head of Echinacea angustifolia, made up of ray and disc florets (Image: J. L. Ison)

Echinacea angustifolia is a long-lived, perennial herb growing up to a metre tall. It has a deep, woody taproot and does not grow clonally. The stems are hairy and typically straight with little branching. The leaves are also hairy and 5–20 times longer than wide. Margins of leaves are entire (smooth, with no teeth). The flower head (capitulum) is 4.0–7.5 cm in diameter and composed of ray-florets and disc-florets. The outer ray-florets are sterile, and each has a long (2–4 cm), purple, petal-like structure called a ray limb. The disc-florets are brownish-purple in colour and form the centre of the head. Each disc-floret has five lobes and is subtended by a stiff bract. The pollen is yellow (an important characteristic that distinguishes it from E. pallida, which has white pollen).

The most recent review of the genus Echinacea, by Binns et al. in 2002, follows the practice of ‘lumping’ (putting plants together in the same group despite minor variations) and only recognises four species. For example, E. angustifolia is not recognised at species level, but is instead considered to be a variety, E. pallida variety angustifolia. Many botanists consider McGregor’s 1968 revision, which recognises nine species of Echinacea, to be more practical and both the Flora of North America and this plant profile follow this scheme.

Like many species, the key threat to Echinacea angustifolia is habitat loss. Less than 0.1% of the North American tallgrass prairie still exists, and current populations of E. angustifolia are highly fragmented. To help ensure the continued survival of many prairie plants, Kew’ s Millennium Seed Bank Partnership works to collect and bank seeds of native prairie plants, including E. angustifolia.

Since roots are used in the herbal pharmaceutical industry, E.angustifolia is also threatened by poaching of plants from wild populations. This can devastate a population because E. angustifolia is slowly growing, typically taking at least three years to flower.

Photo illustrating why Echinacea angustifolia is called the narrow-leaved purple coneflower (Image: J. L. Ison)

Historically, Echinacea angustifolia has been the most widely used medicinal plant by the Native Americans of the Great Plains, and it is still used in traditional medicine today. It is employed for toothaches, common colds and snakebites and as a painkiller.

During the 1990s, ‘echinacea’ became a popular medicinal herb in the mass market, and by 1997 ‘echinacea’ was the top-selling medicinal herb in the USA. Medicines made using Echinacea species have been shown to have antiviral effects and to stimulate production of white blood-cells; they are marketed as products to relieve symptoms of colds and to aid wound-healing. Controversy remains over the effectiveness of Echinacea preparations in the treatment of upper respiratory tract infections, and research in this area continues.

The three main species of Echinacea used by the herbal pharmaceutical industry are E. purpurea (which is easy to grow and therefore generally cultivated), E. pallida and E. angustifolia (the majority of which are harvested from the wild). There is concern regarding levels of sustainable harvesting of the wild-collected species.

Narrow-leaved purple coneflower is cultivated as an ornamental for its attractive flower heads.

Echinacea angustifolia can be seen growing in the Queen’s Garden behind Kew Palace.

Pressed and dried specimens of narrow-leaved purple coneflower are held in Kew’s Herbarium, where they are available to researchers by appointment.

Specimens of Echinacea angustifolia roots are held in Kew’s Economic Botany Collection in the Sir Joseph Banks Building, where they are available to researchers by appointment.

Search Kew’s science databases for more information on Echinacea angustifolia

USDA PLANTS Profile – Echinacea angustifolia

See Kew’s Seed Information Database for further information on Echinacea angustifolia seeds