…rust spores, of course. Endocronartium harknessii. Here’s my new grad student (from Haiti) out learning a little forest pathology, and collecting some samples for my course next fall. Western gall rust, scourge of the lodgepole pine (and sometimes ponderosa). The urediniospores are out now and flying around by the billions, these are some small scruffy trees on a few acres just bought in north-central Idaho, they’re loaded with galls.
Good thing these fungi are host-specific! (at least they don’t infect people) This week we’ll go out after WPBR, there are a few white pines on the property, previous owner planted supposedly “resistant” stock after more or less highgrading all the timber. I know a few local spots with white pine in sufficient numbers to find some rust, hard to believe that the former “King Pine” (=wwp) is the state tree of Idaho, many Idahoans have never even seen one.