Arthonia punctiformis Arthoniaceae
Arthonia punctiformis

Growth type crustose
Chemical results negative. Epithecium K+ pale green

Often a pioneer species on twigs and small branches of trees and shrubs

Immersed thallus, sometimes slightly bleaching the bark, photobiont absent. Small black apothecia, usually immersed and with a thin margin of bark cells. Spores 3(-5) septate, 13-23 x 5-7 Ám, colourless, upper cell not enlarged. Pycnidia absent. Microscope photograph below.

Often occurs with Arthopyrenia punctiformis


Arthonia punctiformis


Arthonia punctiformis

Microscope photograph

Arthonia punctiformis
On Ash branch. Holton Lee, Dorset. February 2013

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