The Powdery Mildews (Erysiphales) of Britain and Ireland: An Identification Guide and Census Catalogue for Wales

Powdery mildews are an important group of plant pathogens that affect a wide variety of plants, both wild and cultivated.

The powdery mildew fungi form a well circumscribed group of parasitic fungi in the Order Erysiphales within the Phylum Ascomycetes (the “spore shooters”). If the host plant can be accurately identified, the task of identifying the powdery mildew is relatively easy. Presented here is a catalogue of host plant species (including cultivars) and their powdery mildews recorded from the countries of mainland Britain and the island of Ireland and the Vice‐counties of Wales. A synopsis of characters is also provided to enable a fungus to be identified where more than one occurs on a particular host. Also included and differentiated in this synopsis are host/fungus interactions reported from nearby in mainland Europe that might be expected to occur in Britain and Ireland.

Over 700 taxa of powdery mildews are known world-wide with just over 200 reported here from Britain and Ireland. Catalogued by the Vice-counties within Wales are over 150 species of powdery mildews. Representatives of all five Tribes of these fungi occur in Britain and Ireland. As many of the wild host plants diminish in extent, the fungi that are dependent on them grow scarcer. This guide, we hope, will stimulate their study and enable conservation priorities to be established.

The main text is in English with a short bilingual summary in English and Welsh