A New Gall on Alder

by John Meiklejohn

Gall causing organisms have a habit of suddenly making their presence on the rural scene - the Oak Marble gall in the 1830's and the Oak Knopper gall in the 1970's for examples. Are we about to see another such outbreak?

Look for a peculiar tongue-like growth emerging from the female catkins, or 'cones', of Alder trees - green when immature but turning red to purple when older. This is the gall caused by the ascomycete fungus Taphrina amentorum.

First seen in Norfolk in 1998, it haas been reported from several counties since. I found numerous galls in Ledbury in 1999 and a single specimen, the first record for Worcestershire, in Larches Wood, near Bayton, on 5th September 2000.

Do send me details of any Worcestershire sightings!