Hypogymnia Lichen Windfall

I return from many of my walks with pockets full of lichen windfall. One of the common finds under trees is two slightly different species of Hypogymnia, a good dye lichen.

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Lichen windfall is perfect for dyeing, since it does no damage to just pick up the fallen lichens. I’m therefore writing a small series of posts on the different species of lichens typically found in windfall, and I’ve already written about Ramalina fastigiata.

This time, I’ll have a look at Hypogymnia physodes and Hypogymnia tubulosa, two common species that are closely related (that’s why part of the name is the same). Also, they do look alike – both are grey-green and foliose (flattened, leaf-like). Hypogymnia physodes, here seen covering a small branch, has flat lobes, sometimes with soredia on the outer part. Soredia is one of the way that lichens can reproduce, and break through the surface in lots of little dots, making the surface look grainy or powdery. In Hypogymnia species, the soredia are found on the bottom side, which folds up on the tips of the lobes, making the grainy lower surface visible:

Hypogymnia physodes covering a small branch. Detail on the right shows the lobe tips folded up, displaying the graininess because of the soredia.

Hypogymnia tubulosa looks a lot like Hypogymnia physodes, but has hollow lobes. In the right side of the image below, the hollowness is visible since I cut one of the lobes:

Hypogymnia tubulosa with a cut lobe on the right side.

Both species are very common, and grow in many places, including on trees, stones, and wooden surfaces. They like growing on acidic substrates, and Dobson’s “Lichens, An Illustrated Guide to the British and Irish Species” mentions that Hypogymnia physodes is among the species least sensitive to sulfur dioxide pollution. Hypogymnia tubulosa is a bit more sensitive.

The dye content sometimes differs a lot even for species that are otherwise very similar. So I decided to test if the two species give the same color.

I used unmordanted yarn, since lichen colors are substantive. I made one dyebath with 9 g of Hypogymnia tubulosa, and put a 12-gram skein of Fenris (pure wool) and a 5-gram skein of Bestla (merino-silk) in. Another dyebath was 15 g of Hypogymnia physodes, and two 12-gram Fenris skeins and one 5-gram Bestla skein went into that one. So half the weight of lichen compared to fiber in both cases. I modified one of the Fenris skeins in an iron afterbath.

Both lichens give the same color – a fine, dusty yellow, the completely expected shade from bwm lichens. So in conclusion, no reason to sort Hypogymnia physodes and tubulosa. The merino-silk takes the color a little less well than the pure wool, and an iron afterbath does significantly darken/sadden the color at turn it green.

Left: pure wool and merino-silk dyed with Hypogymnia tubulosa. Right: pure wool and merino-silk dyed with Hypogymnia physodes, further right a pure wool skein dyed with the latter, modified with iron.

Lichen Windfall

Lichen windfall is perfect for natural dyeing, since it does no harm to pick up the fallen ones, they will no longer grow. One of the most common and easy-to-recognize lichens in windfall is Ramalina fastigiata.

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When walking outside on rainy, windy days, I very often find lots of lichens scattered on the ground under trees. Lichens that the wind has torn down from branches. Sometimes, on the day after a big storm, I’ve come home from walks with all my pockets plus random trash bags filled with windfall. Wonderful windfall with that amazing scent that only lichens have.

Collecting windfall does no harm, since these lichens are not able to continue growing anyway. It’s the best (some would say only) way to obtain lichens for dyeing. When I come home with such a treasure, I usually spread it out on a plastic tray to dry (to prevent mold).

Lichen windfall drying at home. It looks like a big piece of Evernia pruniastri on the left, Ramalina fastigiata on the right, and probably a Parmelia species on the bottom.

But before dyeing with lichen windfall, it’s necessary to sort the lichens and determine the species, since you will need to use the boiling water method (BWM) with some species, and the ammonia method with others:

Boiling water method – it is what it sounds like. Simmer the lichen in water and cool off. Add the yarn to the dye bath and heat it for an hour without boiling.

Ammonia method – the difficult one. Steep the lichen in 1% ammonia (originally, stale urine was used) for several weeks or months, opening and shaking the jar daily to aerate. The red liquid in the jar is the dye bath.

In both methods, no mordant is required, since lichen dyes are substantive (they bind directly to wool without the help of a mordant).

Lichens steeping in 1% ammonia.

In order to type lichens, I recently bought myself a copy of “Lichens, An Illustrated Guide to the British and Irish Species” by Frank S. Dobson. It contains a detailed introduction to lichens, and a detailed key with photos and descriptions.

With my copy of Dobson, I’m planning to take a closer look at the types of lichens that are commonly found in the windfall here in my corner of Denmark. That is, how to recognize them, how to dye with them, and which colors to expect.

I’m beginning with a very common type of lichen, which may very well be the easiest one to recognize: Ramalina fastigiata. Often, large tufts of this will fall, and they are completely covered in small outgrowths that look like tiny suction cups. The outgrowths are apothecia, the fruiting bodies of the lichen. They make spores for sexual reproduction. When the spores germinate in a new location, they meet with a new alga to become a new individual lichen. But the dyer doesn’t have to worry about all that, being able to recognize apothecia is the important part.

A piece of Ramalina fastigiata, completely covered in apothecia. Tufts like this can measure up to about 5 cm (2 inches).

Karen D. Casselman mentions the Ramalina species on the list of ammonia methods lichens in her book, “Lichen Dyes, The New Source Book”.

I’ve previously tested the ammonia method on Ramalina fastigiata and achieved a light rose color (pictures here).

But Casselman also mentions the and Ramalina species in her list of boiling water method lichens, so I decided to test that method on Ramalina fastigiata. I used equal amounts of wool yarn and lichen, and achieved no color at all (no pictures!). The conclusion: Ramalina fastigiata is strictly an ammonia method lichen.