Thistle's picture

Usnea subfloridana

Observed: 20th February 2013 By: ThistleThistle’s reputation in Fungi and LichensThistle’s reputation in Fungi and LichensThistle’s reputation in Fungi and LichensThistle’s reputation in Fungi and Lichens
(Usnea subfloridana)
(Usnea subfloridana)
Description:

Found on a twig, possibly hawthorn, under an old hedgerow. Twig approx 1cm diameter. The lichen is a tight grey-green clump 2.5-3cm diameter. There were no apothecia. Main stems blackened at base (see photo 2). Very little cracking of stems visible. I'm confident that it is a Usnea. The closest match I can find is U. subfloridana.

Identifications

Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

Species interactions

No interactions present.

Comments

synan's picture

I have agreed, but...

I think U. wasmuthii still stands in the way:

http://www.irishlichens.ie/pages-lichen/l-371.html

I gather that the nature of the cracking at the base can sometimes be used to split the two, thought PW James states this isn't always reliable. Smith et al. suggests a x50 lens (more like a stereomicroscope!) to examine the base - sounds excessive to me, unless the longitudinal cracks in U. wasmuthii are very subtle indeed.

The test with Pd seems a way in. Using more accessible chemicals, U. wasmuthii is claimed to be K+ yellow-orange vs. the K+ yellow of U. subfloridana. If ambiguity remains, thin layer chromatography is needed.

Usnea must be tree-dwelling equivalent of Cladonia - real headache genera.

Nigel