A year ago I was also drawn by the appearance of a bright orange smear on a dead box elder above Goulding Creek in west Oglethorpe County (near Athens, Georgia, US). That post appeared eleven days earlier, so I didn’t benefit from these great observations.

One thing I noticed was that there were distinctive hollow tubular white structures in the upper areas of the orange emergence (seen in the second photo at the link above), and I see them in the second photo on this post as well. The area around them was attended by small flies (unidentified). It had struck me that this was very stinkhorn-like, but stinkhorns are basidiomycetes and Fusarium is an ascomycete so perhaps there’s no connection.

Since then I’ve also seen a similar emergence (Jan 25 2010) on a living black walnut (here).

Thanks for the observation and discussion.

Here are a couple of notes from mycologist Jay Justice:

Deer vomit fungus – not a slime mold but a fusarium species. I can’t
find the species at this time.

Jay

Found this on the web. Bruce Horn was the mycologist that told me what
this fungus was several years ago.

Jay

The occurrence of fusarium merismoides var. chlamydosporale
(tuberculariaceae) in Rankin County, Mississippi.

Article from:
Journal of the Mississippi Academy of Sciences
Article date:
April 1, 2003
Author:
Dukes, George H., Jr. ; McGuire, Gerald M., II ; Jackson, Dionne ;
McGuire, Sarah Lea
More results for:
fusarium species on wild grape vines | Copyright
informationCOPYRIGHT 2003 Mississippi Academy of Sciences. This material
is published under license from the publisher through the Gale Group,
Farmington Hills, Michigan. All inquiries regarding rights should be
directed to the Gale Group. (Hide copyright information)

This report documents the first occurrence of the fungus Fusarium
merismoides var. chlamydosporale (Tuberculariaceae; Ascomycota) in
Mississippi. The presence of this fungus was first observed in a rural
area of Rankin County, Mississippi (Section 9, Township 3N, Range 5E) in
March 2000, as a very wet, brilliant orange mass growing on a wild grape
vine ( Vitis sp.; Vitaceae). The fungus re-appeared on the same vine in
March 2001, and March 2002, lasting for approximately 3 weeks at each
occurrence. It was also found growing on a second host, ironwood (Ostrya
virginiana; Betulaceae), in March 2001, and March 2002.

Samples were collected from both hosts during 2001 and 2002 …

sap from a wounded tree?

Hey MoFunGuy

I passed a link to your observation to some more people for an opinion on
it. I don’t have a clue …

— Feral Boy