Plant Galls

I will freely offer my services to help with the identification and recording of Plant Galls so I will start with some common questions.

1. What are Galls. A gall involves an intimate association between two oraganisms which are largely parasitic, the gall causer being the parasite and the organism who's tissues form the gall bearing the host. Put simply a Gall is an abnormal growth produced by a plant or other host under the influence of another organism. It involves enlargement and or proliferation of host cells and provides both shelter and food and nutrients for the invading organism. Galls do not kill or harm the host in any way.

2. Why do Galls Form. Galls are formed to protect the larvae of the gall causer and grow in such a way as to Camouflage the gall. Examples of this is Oak Apples and Marble Galls.

3. Where do I find Galls. Galls are found on all plants and some animals but we are dealing with plant galls as they make 99.9% of the subject. Oaks have lots of gall species Violas only one.

4. Is there a site to learn more? Yes. http://www.british-galls.org.uk/ This is the British Plant Gall Society.

5. How do we get them identified. By submitting photographs on here or by writing a description please always include the host plant.

I am hoping to start a thread topic for Galls so if you want a specific thread for these let me or the mods know (I have their permission.)

 

benacre - obviously an interesting subject - but I must admit I haven't been aware on any of my perennials. Are there ones that I should have seen, or do they just occur mostly on trees?

 

Galls in Perrenials tend to be in flower heads normally the flowers will not open and the heads are swollen or the buds are enlarged ie Big Bud in fruit. some Perrenial stems may have swellings. Shrubs and trees seem to produce the more common Galls. you really have to search for Galls on Perrenials as they can be so insignificant.

 

Thanks benacre - I will keep a look out in future. Is fasciation (the growing of several stems into one) in any way connected or is it quite seperate?



I saw an amazing example of fasciation last summer near here. Its a Verbascum, if you didn't recognise it.

 

No fasciation is caused by a virus usually fungul to put it human terms it is a proliferation of cells super annuated upon themselves like a benign tumour