“Speckled Wart Lichens”: {Astrothelium sp.}

Astrothelium (aka “Speckled Wart Lichens”) see “Trypethelium”

Identification Characteristics

Description: Tropical crustose lichens, with thin, continuous thalli largely within bark tissue. Photobiont green (Trentepohlia); perithecia clustered & buried in yellow or orange warts (pseudostromata) as in Trypethelium; perithecia with several chambers but joining at the apex & opening to the surface by a single asiole; spores colorless, narrowly ellipsoid to fusiform, with gelatinous halo, 4-10-celled with lens-shaped locules, turning blue with IKI in some species.

Chemistry: Thalli often containing lichexanthone (UV+ yellow); warts covered with yellow to orange anthraquinone pigments (K+ red-purple)

Substrate: On bark

Range: In tropical & subtropical forests.

Lookalikes: Because some species of Astrothelium intergrade with species of Trypethelium, the boundaries of the two genera are still uncertain. In Trypethelium, the perithecia have only one chamber.

Bibliography: Lichens of North America, by Brodo, Sharnoff, & Sharnoff

Database Entry:  Distance Everheart 12-26-13

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