botanist presses specimens of plants for study and comparison
with other specimens of similar species that have been gathered
at different times and places, worldwide. Meriwether Lewis knew
that his studies in the field would be backed up by the most
prominent cabinet--that is, laboratory--botanists of his day.
Among them was to be Frederick Pursh (1774-1820), a German
botanist whom Lewis hired at Philadelphia in May of 1807, paying
him a total of seventy dollars to assist him in preparing his
collection for a planned, but never written, publication of his
own. Pursh examined 124 of Lewis's specimens, verified or
corrected Lewis's descriptions, assigned names to the ones that
were new to science,1 painted water colors of thirteen of those,
and in 1814 included them all in his two-volume Flora Americae
Septentrionalis (FLO-ruh a-MAY-ree-kay sep-TEN-tree-oh-NAL-iss;
Plants of North America). A field botanist places the leaves,
stems, flowers, fruits, and roots between pieces of soft, loose-
textured, highly abso