Mount Washburn, the principal peak in the volcanic Washburn Range, is an important site for both tourism and research in Yellowstone National Park. This paper provides: 1) descriptions of plant community types on Mt. Washburn, 2) biogeographic comparisons of species diversity for several ranges in the North-Central Rockies, and 3) an annotated species list of the alpine vascular flora, including summaries of constancy, local abundance, and preferred habitats. The alpine flora consists of one hundred and twenty-six vascular plant species from seventy-five genera and twenty-eight families. Biogeographic analyses suggest that the flora is depauperate for the region, with relatively low rates of colonization. These results agree with the predictions of the theory of island biogeography for small isolated ecosystems, and emphasize the vulnerability of Washburn to sub-alpine encroachment as the result of climate change.

Limited information exists regarding the impact of fire on annual plant composition in creosote bush scrub vegetation. The impact of recurrent fires on annual plants is even less understood. To investigate this matter, annual vegetation was sampled in a stand of creosote bush scrub in western Coachella Valley, California that had recently experienced two wildfires. The wildfires fragmented the once contiguous shrubland into three sections: unburned, once-burned, and twice-burned stands, all of which were separated by fuel breaks that contained each fire. For all three stands, annual plant cover and species richness were determined in the field, soil seed bank samples were collected and assayed in a glasshouse, and soil chemistry and physical properties were measured. We found that invasive annual grass cover was highest in the twice-burned stand and native annual plant cover was greatest in the unburned stand. Native annual species richness significantly decreased each time a stand burned resulting in low native annual plant diversity. Seed bank assays revealed that invasive annual grass germinants were orders of magnitude greater in the twice-burned stand compared with the other two stands. Lastly, soil total N, C, and soil pH were elevated in both burned stands. Overall, we found that recurrent fire can result in strong impacts to annual vegetation; however, the twice-burned stand was sampled only three years after burning while the once-burned stand was sampled 20 years after burning. Thus, longer-term fire effect studies plus replication with additional study sites are still needed to improve our understanding of how recurrent fire impacts annual plants.

Calystegia sepium (L.) R. Br subsp. binghamiae (Greene) Brummitt (Convolvulaceae), until recently presumed extinct, is elevated to species status. The basionym Convolvulus binghamiae Greene was published without identifying a type; therefore, a lectotype is selected from among the specimens cited in Greene's description.

A new species of monkeyflower, Mimulus sookensis, is described. This species is found throughout the southern portion of Vancouver Island, the Gulf Islands of British Columbia, the San Juan Islands of Washington state, the Willamette and Umpqua River Valleys in Oregon, and has been collected at one location in Mendocino County, California. Mimulus sookensis is a tetraploid species (n  =  28) derived from the predominately outcrossing Mimulus guttatus DC. (n  =  14) and the predominately self-pollinating Mimulus nasutus Greene (n  =  14). Mimulus sookensis is similar phenotypically to the small-flowered M. nasutus, but differs in chromosome number, height, and by a slightly more narrowed corolla tube than that of M. nasutus. It is commonly found on wet hillsides, seeps, cutbanks, and in roadside ditches, often co-occuring with M. guttatus but infrequently with M. nasutus.