The MGS Forum
Gardening in mediterranean climates => Pests and diseases => Topic started by: Umbrian on November 04, 2012, 08:50:53 AM
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Another request for ID - this time a rather beautiful fungal? growth that I spotted on one of my prostrate Cotoneasters. Looks rather like an immature, white coral formation.......hope it is not harmful ???
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It looks amazing. I can't really see what it is. Are you sure it's fungal? Could it be an insect colony?
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Your pic has had me thinking for some time. I do not think it is anything specific to Cotoneaster.
Did you check to see if there are insects such as aphids, mealy bugs living inside, as suggested by John.
I have been doing somework on cactus and note that many species are covered with a fine down or hyphae which help cut down transpiration in hot weather. Could this be a physiological repsonse from the plant................. !!!!!!!!!!!
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At first I thought it looked like a coral fungus, but I wonder if it may be a slime mold, These were formerly classified as fungi, but they are no longer grouped in the same kingdom. I’ll try to show the photo to a slime mold specialist here in Norway. These are very intriguing organisms, some of them are showing some kind of intelligence in spite of having no brain.
Carol, is the white growth on your cotoneaster soft or rubbery?
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I sent the photo to one who is very knowledgeable on slime molds and who has described several new species. He said the resolution of the photo was too low to see any details, but he thought the center part of it could look like an immature slime mold (myxomycetes), but the peripheral parts seemed to be somewhat fluffy, which is not so typical for slime molds. Slime molds also mainly develop on rotting material, and seldom on fresh plants. He was interested in hearing how this blob develops (matures), so keep us posted.
He also said that he now and then meets natural phenomena where he can’t be sure which ‘kingdom’ they belong to; his only alternative suggestion was that it may be some kind of insect spin.
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Nature. It is enough that we have to worry about porcupines having an excellent memory and returning to the site of a once-food-source over and over again. Now we have slime moulds which seem to know how to slime towards a food source without using any brain.
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They not only know how to find the food, but they also know how to find the shortest way. The species Physarum polycephalum has been shown to be as good or even better than traffic experts in designing the most efficient transport network, see article in Wire (http://io9.com/5452969/what-slime-molds-and-subways-have-in-common-according-to-scientists). A crazy? professor here in Oslo was presented in a radio program, he described how a slime mold colony in his laboratory was influenced by voices and music, it was very entertaining.
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JtH you mention........"some of them are showing some kind of intelligence in spite of having no brain." Are you referring to some of our politicians.?
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Not really, they supposedly have brains, I don't know about intelligence
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I got more information from some Norwegian experts, they say that if it is slimy at this stage, it is probably Mucilago crustacean , or Dog Sick Slime Mould (not very poetic name, I prefer the Norwegian one, ‘heksespytt’, or wich’s spit); if it is dry and woolly, then it is not a myxomycete. Many photos on the Internet certainly resemble your cotoneaster decoration.
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Many thanks to all members who have taken an interest in this posting. After several days of torrential and incessant rain (10% of our yearly average fell in one 24hr period) the "growth" is badly affected. On investigating it yesterday I found it had lost its unusual form i.e. looking rather like a coral formation and had in the main turned a dark grey. I scraped what remained away and it had a soft but slightly gritty texture, definitely not slimy. Will keep my eyes open for any further such growths. ???
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Mind its not catching. We hear all sorts of stories about crossing the species divide, so be careful.
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Carol, I sent your description to my slime mold connection (he is absolutely not slimy): the description you gave about the texture and grittiness confirms the identification, it is most likely Mucilago crustacea. When it matures, the slimy character disippears and the chalky content of the coating will feel gritty, and the colour is often grey when it has crumbled away, the spore-mass is black and spores dark brown or dark purple. If some material had been collected, the spores could have been microscoped for verification. The name crustacean also indicates it's chalky character. For further description, anyone who is interested can take a look at this link http://webcache.googleusercontent.com/search?q=cache:http://myxomycet.com.ua/eng/taxa/mucilago_crustacea.htm.
David, I'll be careful about any crossing with this creature, which is now considered to be an animal (amoeba), and not a fungus.
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Well we seem to have come to a conclusion about the identity of my Cotoneaster "guest" and again thanks to all who took an interest especially you Jh. - shall stick to the "witch's spit" description however rather than your alternative! It drew my attention because of its colour and, on closer inspection, its form and I immediately thought of coral.not knowing there was indeed a large group of fungi under this general descriptive name. Subsequent research on member's suggested websites was fascinating and has certainly increased my knowlege of fungi - not something I have ever really taken the time to study in any detail as I am severely allergic to all types and even a small piece of cultivated mushroom eaten inadvertently can make me ill for days :(
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This looks very much like your slime mould, Umbrian. It was seen growing on "weeds" (grass, Oxalis pes-caprae etc).
It had a powdery texture.
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Yes, Alice, it does look like the growth I had but fortunately I have never seen it again on anything since the rain "did for it" on the cotoneaster. :)