Images of British Lichens
Usnea glabrescens (Nyl. ex Vain.) Vain.
Fruticose, ± tufted to pendulous, much branched, yellow-green to grey-green, black at base of main stem, the main stem just above the base with fine, transverse but not longitudinal cracking, branches not or only slightly constricted at their bases, terminal branches extended, flexuous, with small, rounded, often concave soralia, isidia absent (at most some slight presence on "young and punctiform soralia", fide Clerc in Nordic Lichen Flora 4, also Tõrra & Randlane (2007), as visible in photograph below). Widespread, at least in the west, typically in damp scrubby woodland, resembles the much more common U. subfloridana and probably overlooked.
Refs: Nordic Lichen Flora (2011) 4: 120, 169 (photos, printed too dark); James (2003), 25 (line illustrations); Smith et al. (2009), 927; Purvis et al. (1992), 627; Dobson (2005), 446; Dobson (2011), 452 (photo); Tõrra & Randlane (2007), 422 (photo), 428; Holien & Tønsberg (2008), 67 (photo); Stenroos et al. (2011) 479 (photo); Hinds & Hinds (2007), 498.
|On Oak (Quercus robur), Orielton, Pembrokeshire, May 2009: thallus in situ; fine branch showing soralia; primary branch;|
blackened stem-base. Identity confirmed by Pat Wolseley (TLC demonstration, chemotype with salazinic and norstictic acids).
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Uploaded May 2009, last updated January 2016