ID acorn deformities

[jojo]

Went for a walk this morning and found a couple of oak trees and most of the acorns on them have some deformities. These are growing out of the acorns themselves and I was wondering what the causes might be. Any comments much appreciated.

 

[Ed]

They are called Galls and are caused by a wide variety of things including mites, wasps, bacteria interfearing with the natural growth process of the acorn..... you can usualy identify what has caused it by the type of gall. Your one there looks like a knopper gall which is caused by the gall wasp.

Have a look here for a few different types
http://www.hainaultforest.co.uk/3Oak galls.htm

Ed

 

[KAE1]

Actions of the gall wasp grub I believe.

 

[Grooveski]

They make a nice dye. Oak Gall is on my scribbled list of "shades I like on Toddy's colour wheel".

But was it the nice brown or the nice green? Brown I think.

 

[jojo]

I hadn't realised there were so many different versions! Quite fascinating to read on the site you gave Ed. Thanks for the info. Also interesting to find out about using them to make dye. How are they used, then? Do you have to wait until they are "ripe" and what can you dye with them, ie would it work on leather for example?:You_Rock_

 

[gregorach]

Not sure about dyeing, but I do know that oak galls can be used to make ink. I'm sure it's been discussed on here before, but I can't seem to find it... The wikipedia page is OK, but it doesn't have a recipe. I'll dig one out...

 

[gregorach]

OK, this is the ink recipe I've got:

10oz gall-nuts
3oz Roman vitriol or green copperas
3oz rock alum or gum arabic

Grind into a powder, mix with water (quantity unspecified) and bring to the boil.

Haven't tried it, so I can't comment on its efficacy, and I don't know where you get copperas (ferrous sulphate) from. And I don't know if certain galls are better than others...

Apparently these inks bind chemically with vellum parchment by a process similar to tanning, so I guess it might work on leather quite well.

Hopefully Toddy will be along shortly to enlighten us all.

 

[Grooveski]

How are they used, then? Do you have to wait until they are "ripe" and what can you dye with them, ie would it work on leather for example?

I honestly have no idea. There seems to be so many ways of making dyes that I was just narrowing down the colours that I liked, then was planning on collaring Toddy at a meet for info on the select few.
Trouble is at meets there is so much going on that remembering all the wee things you want to talk about.......

 

[Ed]

You can use them at any stage for making dyes, you'll just get a different shade or colour if they are left to ripen .... according to karen my better half


Ed

 

[demographic]

Just adding to this thread because a while ago I was working at a place with masses of oak trees about, some of which had galls created by the knopper gall wasp...

I found a few acorns that werent damaged from several trees) and as they were sprouting I planted them. Some of the acorns has whats gets described as a "mossy cup" and at the time I identified them as Turkey oak on the basis of that.
Now I have managed to grow this small oak and its still looking like a Turkey oak or one of its derivitives (Maybe a Fulham oak).

Thing is that I have only just read that the Knopper gall wasp requires the Turkey oak for one stage in its breeding cycle then moves onto the normal oak (Pedunculate Oak) where it creates the knopper galls.
Its only in the last few days that I have worked out most of this as I only recently bought a book with more information about trees than the usual Collins Gem.

I read that Turkey oak are often killed off in order to give Pedunculate Oak a better chance without the knopper gall wasp so by the looks of it I am going to have to kill off the Turkey oak which seems a shape cos I was quite chuffed about it growing, rather like its slightly different shaped leaves as well.

This is an article I spotted on the net about it all.

We have two native species of oak in this country – the sessile oak and the pedunculate oak. Sessile means having no stalk and pedunculate means having a peduncle or stalk. In the case of oak trees, this means the sessile oak has acorns stuck to the twig with no stalk. This oak tree is also known as the Irish oak and grows on acidic soils in places like Killarney and Glenveagh. It is perfectly happy and has no nasty extuberances emanating from its acorns.

The pedunculate oak has its acorns out on stalks. It is known as the English oak and can grow on heavy lowland soils and put up with flooding. Such an oak occurs in places like Charleville in Offaly and in Abbeyleix. It is quite often planted as a parkland tree. This is the species that is shown here with its stalked, knobby acorns – one of which is sporting a knopper gall. This gall was caused by a wasp-type insect with the name Andriscus quercusalicis, which laid an egg in the forming acorn. The reaction of the egg with the growing acorn tissue caused it to change its growth form and produce this invading mass of cells, which are in fact food for the growing baby wasp.

This gall wasp has the most amazing life cycle. It has alternating sexual and asexual generations and it needs two oak species – the native pedunculate oak and the introduced evergreen Turkey oak – in order to complete its life cycle. The female wasp first lays her eggs on the roots of the Turkey oak in spring. These grow into sexual male and female wasps, which mate in a normal manner (for wasps that is). The mated female then goes and lays her eggs on the developing acorn and the ensuing growing larva causes the disfigurement that we see in autumn on the acorns – the knopper gall. The creatures that emerge from these are all female. They overwinter like this and in spring – without ever laying eyes (or anything else) on a male – go on to lay eggs on the roots of the Turkey oak.

So before Turkey oaks were ever introduced to this country we had no knopper galls. And while every acorn is not so afflicted, you know what to do if you are worried about the survival of your native pedunculate oaks. Get rid of the Turkey oaks in the vicinity and there will be no breeding habitat for those weird, asexual female gall wasps.

 

[bushwacker bob]

Grow the Turkey oak in a pot and keep it as a bonsai.