Phlyctis
Crustose lichens containing a trebouxioid alga; thallus scurfy and areolate, cracked, or immersed, sometimes sorediate, often surrounded by a conspicuous, cottony, white prothallus; apothecia inconspicuous, often covered in scurfy thalline material or soredia; rim poorly formed, the hymenium not well distinguished from the thalline tissues; hymenium formed of mostly straight and unbranched paraphyses not embedded in gel and with air spaces around them; asci broadly elliptical or oblong, thin walled, with a poorly developed tholus, IKI+ in a halo around the outer wall surface; spores 1-2 (‑4) per ascus, muriform, colourless, oblong, elliptical, subspherical, sometimes with pointed ends.
References: Tønsberg 2004b; Galloway 2007.
| 1a. | Apothecia present, thallus not sorediate; spores 90-170 × 25-60 µ …Phlyctis speirea |
| 1b. | Apothecia rare; thallus abundantly sorediate; spores 100-150 × 25-50 µ …Phlyctis argena |
Phlyctis argena (Sprengel) Flotow
Thallus 2-10 cm across, or sometimes several dm wide, verruculose, granular or in part smooth, scurfy, pale green or bluish white, usually surrounded by a cottony pure white prothallus, producing soralia that may become confluent, with the soredia covering most of the thallus; soredia 90-125 µ wide, coloured like the thallus; apothecia rare, usually not raised above the thallus surface, 0.2-0.4 mm wide, the disc appearing as a round patch of cottony white medulla maculated with tiny grey dots (the individual asci); spores 1 per ascus, 100-150 × 25-50 µ, densely muriform, elliptical.
Reactions: K+ yellow turning red, PD+ yellow or orange.
Contents: Norstictic acid and ± connorstictic acid.
Habitat: On acidic bark of trunks and branches, lower to middle elevation forest.
Similar Species: Haematomma ochroleucum may appear very similar, but reacts K+ yellow, not turning red, and PD- or + pale yellow.
Specimens: Björk 14388; Goward 94-861, 03-332.
Local Status: Common.
Phlyctis speirea G. Merr.
Thallus usually 2-4 cm wide, but sometimes more than 10 cm across, smooth, scurfy or sometimes cracked or verruculose, pale grey or pale green, lacking soredia; apothecia in short thalline warts 0.3-0.6 mm wide, the warts with whitish, papery margins, the disc dark grey or brownish grey, but usually covered in thick white pruina; hymenium 100-210 µ high, light to medium brown in upper portions; spores 1 per ascus, oblong, densely muriform, 80-140 × 19-45 µ.
Reactions: K+ yellow turning red, PD+ yellow or orange.
Contents: Norstictic acid and ± connorstictic acid.
Habitat: On acidic bark of trunks and, less often, branches, lower to middle elevation forest.
Similar Species: Scurfy forms appearing like P. argena, but lacking the soredia of that species.
Specimens: Björk 9032, 13187; Goward 94-848.
Local Status: Occasional.
Notes: This species and P. argena intergrade, and may not be truly distinct.