386 BOTANICAL GAZETTE [JUNE 
due to artificial factors, such as the “ breaking ’”’ and the cultiva- 
tion of the prairies. The mistaken idea concerning the distribu- 
tion of Bulbilis has arisen from the statements of trappers, 
scouts, and frontiersmen, who invariably confused, and still con- 
fuse, Bulbilis and Bouteloua, thus assigning to the former not 
only its proper’ geographical area and abundance, but, in addi- 
tion, that of Bouteloua oligostachya and B. hirsuta. Another 
popular fallacy is that the blue stems, Andropogon provincialis 
and A. scoparius, are slowly advancing westward across the 
plains, an advance often connected with the supposed disap- 
pearance of Bulbilis. In fact, both species are as truly endemic 
in the sand hills and foothills as they are on the eastern prairies. 
In addition to Bouteloua and Bulbilis, Drude enumerates Agvo- 
pyron pseudorepens, Oryzopsis cuspidata, Stipa viridula, S. setigera, 
Andropogon Virginicus and A. glomeratus as characteristic species. 
The last two are not found within the prairie province proper, 
Stipa setigera is common only south of the Arkansas, and s 
viridula is abundant only along the foothills, and on the prairies 
of the extreme north. 
That it is impossible for a phytogeographer to treat accu- 
rately the floristic and the distribution of a distant flora which 
he has not seen, is well exemplified in Drude’s Florenkarte si 
Amerika. Quercus rubra, which on his map has a western distri- 
bution running from the southwest corner of Nebraska to the 
mouth of the L’eau-qui-court in the northeast, occurs in the 
state only in the southeast corner in the red oak-hickory forma- 
tion of the Missouri woodlands. On the other hand, the western 
limit of Quercus macrocarpa does not run north and south through 
the sand hills, but bends to the westward, passing beyond the 
Nebraskan border into Wyoming and the Black hills of South 
Dakota. Juglans cinerea and J. nigra, which, according to Drude, 
scarcely cross the Mississippi, likewise occur in N ebraska. The 
former is found in the southeast corner of the state; the latter, 
as a facies of the bur oak-elm-walnut formation, extends halfway 
across the state along the L’eau-qui-court and the cos gaan 
The main features of the regional limitation and character 
