Euphrasia

Euphrasia alpina Alpen-Augentrost

Euphrasia gibbsiae subsp. subglabrifolia

Euphrasia minima

Euphrasia cuneata 11

Euphrasia is a genus of flowering plants in the family Orobanchaceae. Commonly known as eyebright, the genus is native to Europe, Asia, and North America, and it is known for its use in traditional herbal medicine. The plants of this genus are small, annual herbs characterized by their white or purple flowers with yellow spots and stripes, which are thought to resemble an eye, hence the common name eyebright.

Description

Euphrasia species are annual herbs that grow to a height of 2-30 cm. The leaves are opposite, serrated, and lanceolate to ovate. The flowers are zygomorphic (bilaterally symmetrical), which is typical for the family Orobanchaceae. They have a four-lobed corolla with the upper lobe usually being the largest. The flowers are predominantly white, but they can also be purple, with yellow variegations that are said to resemble an eye. The fruit is a capsule containing numerous small seeds.

Taxonomy

The taxonomy of Euphrasia has been complex and contentious, with species numbers ranging from about 450 to 600, depending on the authority. This complexity is due to the genus's high degree of morphological variability and widespread hybridization and polyploidy. Euphrasia was traditionally placed in the family Scrophulariaceae, but molecular phylogenetic studies have since relocated it to the Orobanchaceae family.

Distribution and Habitat

Euphrasia species are found across a wide range of habitats in Europe, Asia, and North America. They prefer well-drained, somewhat alkaline soils and are commonly found in meadows, grasslands, and forest clearings. Being semi-parasitic, they extract water and nutrients from the roots of nearby plants, which allows them to thrive in a variety of environmental conditions.

Uses

Historically, Euphrasia has been used in herbal medicine to treat a variety of eye-related conditions, such as inflammation, conjunctivitis, and blepharitis. It is believed to have astringent and anti-inflammatory properties. Eyebright preparations are used in the form of teas, tinctures, and eye drops. However, scientific evidence supporting the efficacy of eyebright in treating eye conditions is limited, and its use should be approached with caution.

Conservation

Some species of Euphrasia are considered rare and are at risk of extinction due to habitat loss and overharvesting. Conservation efforts are necessary to ensure the survival of these species in their natural habitats.