BioImages: The Virtual Field-Guide (UK)
Cronartium ribicola J.C. Fisch. (White Pine Blister Rust)
||8 October 2009
|OS grid ref
||51° 30' N, 1° 10' W
||Vice County: Berks, VC22, England
(Please quote this in any queries about this record)
|Stage or state
||Hypophyllous telia on fading Black Currant leaves
||hypophyllous fading leaf of Ribes nigrum
||Causes small polygonal brown necrotic spots with slightly darker borders and limited by veinlets; neighbouring area often yellowish. The spots coalesce and eventually cover much of the leaf.
Underneath the spots bear crowded uredia which commence bright, pale orange but soon darken to match the leaf spot. The uredia develop into pale orange columnar telia which soon fade to dirty white. They cover the underside of the leaf so it looks like Terry Cotton. The telia eventually attract dematiaceous hyphomycetes.