Eyebrights catch the eye

Steve Gater DWT Botany Group, News


Traditional meadows are a good place to look for eyebrights

These pretty little plants that flower from June onwards are delightful to see in meadows, on magnesian limestone grasslands, heaths, in open woodlands and occasionally elsewhere. Similar to some other members of the figwort family, Scrophularaceae, they are hemi-parasitic – relying on other plants to survive. Individual species are notoriously difficult to identify because the plants can be highly plastic, a feature that may relate to the type of plant they are associated with, and/or other factors. Identification is also challenging because of frequent hybridization, with hybrids unusually fertile.

 

Euphrasia rostkoviana

Euphrasia rostkoviana
Scientific classification:
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Lamiales
Family: Orobanchaceae
Tribe: Rhinantheae
Genus: Euphrasia

Part of article hosted on Wikipedia – click here for full article

Not surprisingly then, eyebrights (Euphrasia) are classed into a critical group and botanists told to beware of naming them. One guide, Rose, shows only 2 of the 21 known British species (with hybrids to add to that) as an indication of what eyebrights tend to look like. Other guides, such as Blamey, Fitter & Fitter, boldly show 20 species and geographical distribution, but do not venture far into how to identify species with some certainty. Arrrgggghhhhh!

Eyebright – Euphrasia nemorosa, Euphrasia agg or what?

Fear not, however, help is on hand and in fact, literally, just up the road! Enter Chris Metherell, BSBI President, County recorder for North Northumberland, BSBI referee for Euphrasia and co-author of a soon to be published BSBI guide on how to identify eyebrights. He is also a nice bloke who lives near Morpeth. With such an authoritative background, who better to come to our rescue? Chris very kindly accepted an invitation to run a three-hour training session on Thursday 9th March and proved to be inspirational.

Chris at work identifying. Picture courtesy of BSBI

Chris started with an overview of Euphrasia, taking us through the overall characteristics of this fascinating group of plants, explaining the key features of different species, their preferred habitats and pointed out what to look for and where in the North East. He broadly separated eyebrights into two groups, based on chromosome number – plants with 2 sets of chromosomes (2n, diploid) and those with 4 sets (4n, tetraploid). Diploids have long glandular hairs, tetraploids don’t – so we have a starting point for our close observations. He also encouraged us to look at pairs of species such as Euphrasia artica and Euphrasia nemorosa and to compare features such as size, leaf shape and where flowers appear.

Sharply toothed leaves on this one

Having described the features of the separate species and how to consider when we might be looking at a hybrid, Chris then took trainees through a series of steps to try to identify to species level. He did caution on the difficulty of using keys – some simply do not work and certain species are impossible to distinguish between – for example, simply accept that you may be looking at Euphrasia rostkoviana or E anglica!

Chris explained a hierarchy of steps to take to identify fresh plants in the field and invited people to send him quickly pressed specimens for him to check. He took us through the procedure that will soon appear in the BSBI guidebook (expected this Autumn and a ‘must’ buy!). He advised using a 20x hand lens if possible and a scale loupe to measure tiny features – click here for one supplier.

The identification steps include;

  • Knowing exactly where the first flower is positioned on the stem
  • Measuring flower size
  • Describing leaf shape
  • Observing features of the capsule
  • Then comparing all observations to species descriptions and having a go with different keys to see if they work.

With flowering some months away yet, Chris brought a stack of superbly pressed and mounted specimens to allow people to see the salient parts of different species. This allowed the group to see for themselves what to look for and how – wow!

Pressed Euphrasia

What a session – simply brilliant. Chris is widely known as an excellent trainer, and we now know why! The afternoon flew by, Chris’s enthusiasm to find and identify eyebrights was infectious, and the confidence to have a go grew as time passed. Bring on those eyebrights! Let us find new records out there! We will definitely be on the look out for Euphrasia this summer.

Thank you Chris for an inspirational afternoon and for leading BSBI and telling us more about that great organisation. For more information on BSBI activity and membership, click here.

Steve Gater
Chair at Durham Wildlife Trust

Steve has a life-long interest in wildlife and a passion for flora. As an active member of the Durham Wildlife Trust Botany Group Steve enjoys exploring Vice County 66, the area covered by Durham Wildlife Trust, with its many specialities and wide range of common species. Inspired by Albrecht Dürer, Steve is a strong advocate for enjoying, protecting and conserving habitats and the wildlife they support - a fundamental priority for us all!