BioImages: The Virtual Field-Guide (UK)
Unidentified True Fungi (Unidentified True Fungi)
||22 April 2007
|OS grid ref
||51° 10' N, 0° 40' W
||Vice County: Surrey, VC17, England
(Please quote this in any queries about this record)
|Stage or state
||grey leaf-spots on over-wintered leaves
||on live, overwintered leaf of Rhododendron ponticum
||Large leaf-spots, 30-60mm diam., with wavy margin, on over-wintered leaves, usually starting from Vine Weevil damage along the margin or tip, (otherwise perhaps just the extreme centre drops out).
Upper surface: greyish-brown, weakly zonate to silver-grey centre, magin double with wavy black inner margin, separated by a pale band from a deep purple outer margin.
Under surface: brown, with central zone silver grey, otherwise hardly zonate, border double: narrow (<1mm) dark brown within, 1-1.5mm broad pale or greenish zone, then broader (1-3mm) pale purple outer margin.
Pycnidia not seen (appearance confused by Doratomyces stalk bases and hypophyllous punctiform colonies of sooty mildew/fly-speck fungus)
Pale punctiform superficial epiphyllous deposits (like extruded spore masses) in the brown zone. These contain cystidia-like cells, often with swollen 1-septate bases, but no spores seen.