Popis: |
Previous phylogenetic analyses of Lepidium included only a few accessions of L. montanum, L. flavum, and L. fremontii to represent western North American species. Two additional species endemic to southwest Idaho have posed both taxonomic and conservation questions regarding their species status. Lepidium papilliferum was originally described as a variety of L. montanum, is morphologically similar to L. montanum, and is found in small scattered populations in southwest Idaho. The plant is restricted to specific edaphic conditions known as slick spots where high clay content creates conditions amenable to L. papilliferum, but to few other species. Resolving whether the populations of L. papilliferum merit species status distinct from L. montanum is a vexing question and phylogenetic analyses can assist in resolving this issue. Like L. papilliferum, L. davisii has specific edaphic requirements and is found in playas, areas similar to slick spots, but larger and with deeper soils. Unlike L. papillif... |