Re: [IUFRO RG 7.02 FORPATH] FW: Bumps on Beech

Sorry: I attached a version of the photo without the arrow but the woody connection can be seen as a slight point on the left-hand side. David On 2013-01-30 12:51, d-lonsdale wrote: often see similar bumps on European beech and have identified them as sphaeroblasts, which are thought to develop from dormant buds. In place of a shoot, a ball of wood develops, encased in bark. A sphaeroblast can be easily detached with a mallet etc., since its woody connection to the stem is very narrow. The large sphaeroblast in the attached picture shows an arrow pointing towards the woody connection on the proximal side. Some of the bark has been pared away with a knife to expose this connection. The picture also shows wood exposed on the proximal side (with partial occlusion), perhaps because of an old injury or as a result of bark dieback. Similar canker-like areas can be seen on the bumps in John McLaughlin's photos but I doubt whether these bumps are sphaeroblasts, since their close alignment is unlikely to correspond with the positions of dormant buds. can also be induced by the scale insect Xylococculus betulae, which penetrates as far as the cambial zone (especially in the aftermath zones of beech bark disease [see Dave Houston's article in J. For., 73(10), 1975]. I think that they usually look rougher and corkier than the bumps in John's photos but my experience of this insect has been limited to looking at photos and to two brief visits to the USA. regards, rg70200-forpath-bounces(a)lists.iufro.org [mailto:rg70200-forpath-bounces@lists.iufro.org]On Behalf Of Bonello, Pierluigi RG 7.02 FORPATH] FW: Bumps on Beech received these photos from one of my forest pathology students and I must admit I've never seen these things before. Can anyone help? Thanks! > > Enrico > > Pierluigi (Enrico) Bonello, Professor Dept. of Plant Pathology 688-5401 http://cmib.osu.edu - http://caps.osu.edu my program to foster research on woody plant health with a tax-deductible charitable donation? Click here! Saintignon David N." , Pierluigi Bonello , Dan Herms wart-like mounds on its bark. Is this normal for some beeches, or could it potentially be a paper topic? Do you know what it is? -Diana