Pithomyces spp.

Spores of Pithomyces spp. are fairly common in outdoor air samples.  The spores can sometimes be differentiated from Ulocladium spp. as the spores have a definite attachment point with a small transparent frill at one end.  The other end of the spore is round.  As the spores mature the exterior becomes roughened with small spines. 

The organism will grow on textiles, paper and wood products inside buildings.  It will grow on dead trees, and dead grass in the outdoors.  It can cause facial eczema in ruminants eating contaminated grass. 

The barrel shaped spores are approximately 15 to 25 microns in length and 10 to 15 microns in width.  These larger sized spores will deposit in the upper respiratory tract.   

A photo of Pithomyces spp. at various stages of growth on a culture plate - N. Carlson

Mature dark colored spiny Pithomyces spp. spores in culture - N. Carlson

Pithomyces spp. from an Air-o-cell cassette spore trap - The spore is dessicated (dried out ).  It looks similar in color and shape to root beer barrel candy.  - N. Carlson

Pithomyces spp. spore line drawing with frill at the attachment point - N. Carlson

Pithomyces spp. information - 2 min.