Thallus very thin, filmy, smooth, occasionally finely scurfy, effuse or immersed, white to pale grey. Isidia and soralia absent. Photobiont chlorococcoid.
Anamorph: conidiomata pycnidia. Conidia 17-20 × ca 0.5 μm, curved.
Teleomorph: ascomata apothecia, 0.25-0.5 mm diam., very numerous to crowded, sometimes scattered on twigs, emergent to sessile. Disc flat to markedly convex, pale pink to red-brown, translucent when wet. Thalline margin very thin, smooth to crenulate, becoming incomplete and excluded, white or pale grey. Proper margin often visible, thin, dark brown. Epithecium brown, hymenium and hypothecium hyaline. Interascal tissue of paraphyses, thick-walled, usually unbranched, conglutinated, sometimes sub-moniliform, the apices not pigmented. Asci 8-spored. Ascospores 10-16 × (3-) 4-5 μm, narrowly ellipsoid to fusiform, 1- (to 3-) septate, generally inaequilateral when mature, hyaline, smooth, thin-walled, without an epispore, gelatinous sheath or appendages.
Assessed by Woods & Coppins (2012) as of Least Concern. This is a common and widespread species.
The wider ascospores distinguish Lecania cyrtella from L. cyrtellina and L. hyalina. The very similar L. sambucina has predominately 12- to 16-spored asci. The presence of occasionally 3-septate ascospores may lead to confusion with L. suavis which is always on rock. Lecania chlorotiza and L. cyrtella have smaller apothecia and narrower ascospores than Biatora sphaeroides. The common Lecanora persimilis has aseptate ascospores.
Throughout Great Britain and Ireland. BLS map here.
On nutrient-rich bark in the Xanthorion, especially on Sambucus, Fraxinus and Acer.