Monday, November 17, 2014

Of smut and wiregrass...

During our native seed collections of 2010 and 2011, I really got an eye for spotting healthy plants and inflorescences with seed suitable for propagation.  There was plenty of time to refine those skills while walking literally hundreds of acres of longleaf pine woodlands.  In that time I also got an eye for spotting plants and seeds that were just plain not right.

A typical stand of longleaf pine and wiregrass at Carolina Sandhills NWR.

 The species that most piqued my curiosity was our native wiregrass (Aristida beyrichiana/stricta).  What I started to notice was a black dust on the seeds and stems of plants along with swollen greenish-black seeds.  Well, I asked around a bit and it didn't take long to find out what I was looking at.  A smut fungus and possibly some powdery mildew.  Now, a lot of folks had observed the smut on wiregrass in their longleaf stands, but nobody could tell me anything else about it.  

A handful of wiregrass culms with evidence of smut.

We hope to change that very soon.  Recently Dr. Joan Walker of the USFS's Southern Research Station initiated a research project with Dr. Julia Kerrigan, an Associate Professor of mycology at Clemson University, to find out just what this smut is and where it exists.

Black powdery spots and streaks on wiregrass seed. 

We hit the ground running in October and our technician, Inga Meadows, has already visited a dozen properties across the Carolinas and into Georgia.  This is an exciting new project that will hopefully shed some new light on wiregrass seed ecology and inform efforts to restore this important native grass to the groundlayer of longleaf pine forests.

A close-up of smut-infected wiregrass seed.

This infected seed will swell until it bursts open.