• Pyrenula acutispora
Pyrenula acutispora
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(Map updated: 11 August 2009)

The yellow-grey thallus with a rather dark and sooty cast that often distinguishes this species in the field from its Irish relatives has a peculiar feature which tells it outright on close inspection: the spherical discs or perithecia have their spore-exit points or ostioles laterally positioned instead of at the apex of the disc. A section through the disc in potassium hydroxide solution (K) shows no reddening of the tissues and an absence of oil droplets which are easily visible under the microscope. Spores are three-septate and about 2025m long. Smooth bark in the vicinity of old woodlands. In Ireland, records are few: County Clare and County Kerry.

Key characteristics

  • Discs (perithecial) skewed with terminal opening (ostiole) laterally positioned or well off-centre
  • Disc tissues unchanged in K without oil droplets; no lichen substances detected.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Pyrenula acutispora . [In] LichenIreland. Accessed on 2019-08-25.