Secretions of Haematoxylum

Mr. Gecko

Hello all,

Haematoxylum campechianum (logwood) can be seen quite frequently in many tropical areas. On Mauritius we experienced that the plant secretes a kind of foamy stuff from little wholes in the bark. The foam is coming out in pulses and rinses down. However insects as well as geckos are attracted by it and lick it away as soon as a new pulse shuffles some foam out of the plant. It tastes sweet and aromatic. When the foam stops coming out these areas become dark probably due to some fungus living on it. We tried to cut the bark or drill a little whole in the trunk but this did not lead to the secretion of this stuff.

My questions would be:
Is it really the plant that produces this foam and why would it do so? It seems unlikely that an insect inside the plant is responsible for the stuff, since the quantity that comes out is far too much.
Is there any literature about this phenomenom?
Is the composition of the secretion known?

I attach two pictures showing what I mean.
Thank you for your contributions.
Regards, Mr. Gecko

derwoodii

Bacterial Wetwood| Slime Flux| Facts

This is called wetwood or slime flux.
The bacterial wetwood is found in the roots, branches, and trunks. The cause of the condition is an infection of the heartwood caused by several common types of anaerobic soil bacteria (bacteria to which oxygen is toxic). These bacteria feed on substances in the wood, releasing fatty acids, methane and carbon dioxide gases. The fatty acids go rancid leaving the wood of the tree water soaked and foul smelling.

The gaseous by-products create a hydraulic pressure which forces liquids out of cracks in the bark, branch crotches and pruning wounds. These fluids will turn brown once they come in contact with air, and leave a slimy, fetid ooze dripping down the bark. The liquid raises the pH of the tree making the interior more alkaline. The bacteria do not cause any wood decay, and infected wood is also very resistant to decay.
There is no satisfactory control for bacterial wet wood. It does cause die back of branches, but the raised pH prevents decay fungi from rotting out the centre of the tree.

Sap may continue to ooze for several weeks or months, but usually it eventually stops with no treatment and no apparent damage to the tree. This slime flux may be triggered by heat, drought and other stress.

There is no curative or preventive measures for slime flux except to maintain trees in a general good state of vigor and minimize wounds and injuries. More damage can be done to the tree in attempting to cure slime flux than the flux will do alone. If there is loose or dead bark in the slime flux area, remove all of the loose bark and allow the area to dry. Do not apply a wound dressing. A solution of 10% sodium hypochlorite (1 part household bleach to 9 parts water) will help surface disinfect the area around the damaged area. This will help discourage insect attraction and help restrict damage to the bark below the damaged oozing area.

Brent Ferris

I agree with Derwoodii - wetwood - tho I don't think I would taste it - the smell from the trees here puts one right off.

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Mr. Gecko

Thank you for your answers.
Bacterial fermentation as a cause seems plausible to me. However there are some differences to wetwood (at least from what I’ve got from the link attached by derwoodi):

- The foam is absolutely not malodorous. To my memory it had no particular smell. Otherwise I would not have tasted it. Also geckos would not have any interest, they like it sweet.

- The secretion is not slimy it is foamy like beaten egg white

- It is sweet and aromatic, arguing for ingredients coming from the tree itself. Bacteria would have used up the suggar. The consistence is a bit fatty.

- It is a time resticted phenomenom. Foam is coming out only for some time. However, probably due to mould living from the stuff running down the tree one can notice such areas by their dark appearance on many Haematoxylum trees.

In one of the pdf files attached to the link above, I found this passage:
„Wetwood slime is distinct from the white or "alcoholic" flux that marks sites where microorganisms infect shallow wounds in the bark and cambial region (see Plate 78). Alcoholic flux is nearly colorless and acidic, often gives off a pleasant fermentative odor, and persists only a short time in summer“

Although the foam was neither acidic nor alcoholic I would be interested whether anybody has more information on this “white flux”.
Thank's for further postings.

Jeff Darby

While searching another topic I came upon this page.Bacterial Wetwood - Prevention and Control of Slime Flux further reading for those interested.

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