First report of grass species (Poaceae) as naturally occurring hosts of the pine pathogen Gibberella circinata.
Gibberella circinata causes pitch canker in pines and is not known to have any hosts outside the Pinaceae. To determine if G. circinata can also infect grasses under natural conditions, plants were collected in proximity to trees with symptoms of pitch canker in native stands of Pinus radiata on the Monterey Peninsula and P. muricata at Pt. Reyes National Seashore on the California Coast during July and August 2011. G. circinata isolates were recovered from Holcus lanatus and Festuca arundinacea on the Monterey Peninsula and H. lanatus at Pt. Reyes National Seashore. Results show that grass species can be symptomless hosts for G. circinata, constituting the first documentation of any host for this pathogen outside the Pinaceae.