Phacidium lauri

Phacidium lauri

Alternative names
Phacidium multivalve
Description

Small round black volcano-shaped pustules with pale tips form on the upper and under surfaces of dead Holly leaves.    These are the asexual form, producing conidia. 

Similar Species

Trochila ilicina forms small dark speckles on the upper side of dead holly leaves. 

Identification difficulty
Identification aids

 

Holly Speckle
Trochila ilicina
Phacidium lauri Phomopsis crustosa Microthyrium ciliatum
There are some nice comparison images of species 1, 2 and 4 here.
Small (<1mm) speckles on the upper side of the leaf only. Pustules (c.1.5mm) on upper and lower surfaces of the leaf. Immersed black conidiomata (0.5mm) on brown spots surrounded by a narrow black line. Tiny black speckles (<0.5mm) on both sides of the leaf.
Recording advice

Your photo should show the pustules in situ on the leaf and also in close-up. Check whether the speckles are on upper or lower side of the leaf, or both, and note this. Also note the substrate and associated tree species in your comments.

Habitat

Fallen Holly leaves.

UK Status

Widespread and fairly frequent in Britain.

VC55 Status

Status in Leicestershire and Rutland not known.

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Additional images

All NatureSpot records

Photo of the association

Holly

The round black pustules of the fungus Phacidium lauri are found on dead Holly leaves.