An unsustainable trade

Guest post by Isabella Whitworth (@Orchella49).

Roccella gracilis on wool yarn that has been dyed with orchil made from Lasallia pustulata. Image credit: Isabella Whitworth .

Lichens are complex plant-like organisms made up of a fungus and an alga or cyanobacterium that live together in a mutually beneficial relationship (symbiosis). They are often found attached to rocks or trees and species can vary hugely in appearance, from flat, crusty forms to leaf-like growths. Certain species have been used as dyestuffs for millennia, although not all lichens produce dye.

My research into dye lichens was triggered by a chance mention of ‘an archive in the attic’ by local friends. Their forebears were dye manufacturers in nineteenth century Leeds in the UK and the company archive had been passed down three generations. The company’s initial fortunes came from the successful processing of orchil, a dye made from lichens.

Find about more about fungi for UK Fungus day

The archetypal poisonous mushroom Amanita muscaria or “Fly agaric toadstool”. Growing under a stand of Pinus radiata in Wellington, New Zealand. Image credit: Tony Wills, distributed under a CC BY 3.0 licence.

Sunday 13th October is the first ever UK Fungus day! There are lots of events happening all over the country to raise the profile of fungi and fungal research. To celebrate I’ve put together a linkfest of recent articles all about the fungi.

Firstly, if you dont know the difference between a fungus and a mushroom it is worth starting with Kirsty Jackson’s post on fungi on this blog. And (just in case you missed it) her post on today’s cover mushroom  fly agaric.

Guest post. Lichens: More than meets the eye

By Kirsty Jackson (@kjjscience)

Have you ever been for a walk, or sat in the park, and wondered what that weird stuff  growing on the side of the trees, on walls, or even the very bench you are sitting on is? Chances are that what you are looking at is Lichen. Lichens can be a range of colours from green, grey and even orange. They are often overlooked as insignificant, thought of as a nuisance or even mistaken for moss but if you look a little bit closer you’ll see they are something quite remarkable.

Image by Trevor Rickard. Click image link for licence information.

Lichens are not a plant. Lichens are in fact made up of both a fungus (mycobiont) and a photobiont (either algae or cyanobacteria). They form a stable, self-supporting association, or mutualistic symbiosis with each other, where the photobiont lives within the fungus. It’s for that reason that Lichens do not have a taxonomic group of their own like mosses or ferns do. Lichens are polyphyletic, meaning that the lichen lifestyle has evolved more than once and are named after the fungal symbiont. Approximately one fifth of all fungi become “lichenised” and roughly 1700 different lichens are found in the UK and Ireland.