Abstract:
The California vernal pool-endemic grasses Orcuttia tenuis and Tuctoria greenei, both listed under the
U.S. Endangered Species Act, were recently found in Modoc County, California, a short distance south of
the Oregon border. This prompted searches in suitable habitats in adjacent portions of the Klamath Basin
in Oregon, in the Gerber Block Bureau of Land Management lands and adjacent portions of the Fremont-
Winema National Forest. Neither species was found in the 2010 or 2011 surveys. The 2009-2010 winter
through summer was very dry, possibly causing dormancy of these species in soil seed banks that year.
The 2010-2011 winter through summer was much wetter, so much so that the pools desiccated very late,
perhaps furthering dormancy. Alternately, the species may truly be lacking from the Gerber Block.
Twenty-six species ranked for conservation by the Oregon Biodiversity Information Center were found in
the 2010 surveys, and an additional 10 species were found that should be considered for listing as
conservation priorities in Oregon. A number of vascular plants and lichens were found that may represent
taxa new to science. In vernal pools, 149 taxa (all but 9 of them native) were recorded. A preliminary
sketch is given of character species, high-frequency species, species autecologies, and plant communities
of vernal pools in the project area. Further notes describe additional ephemeral wetland types encountered
in the project area.
