Plant Migration Studies 17 



Post Oak (Qncrcus minor (Marsh.) Sarg.) is found in the 

 Missouri forests, from which it is reported to have moved north- 

 ward (54) into southeastern Nebraska (Sargent). 



Bur-Oak (Ouercus niacrocarpa Michx.) is abundant in the 

 Missouri River valley forests, from which it has migrated along 

 the river valleys fully half way across the state (55), reaching 

 Harlan County on the south, Custer County in the centre and 

 Cherry County on tlie north. It occurs, also, in the Black Hills 

 of South Dakota, to which it was probably brought from the 

 same Missouri forest area. 



Yellow Oak {Quercns acuminata (Michx.) Sarg.) found in 

 the Missouri forests, has barely reached Nebraska (56) in Rich- 

 ardson County. 



Low Yellow Oak (Oiicrctis prinoides Willd.) of the Missouri 

 'forests has barely reached southeastern Nebraska (57) in Rich- 

 ardson County. 



Red Oak (Quercus rubra L.) is common in the Missouri for- 

 ests, from, which it has been carried northward along the Mis- 

 souri River to Dixon County (58) and westward fifty or sixty 

 miles. 



Scarlet Oak (Quercns coccinea Muench.) occurs in the Mis- 

 souri forests, and has entered the southeastern counties of Ne- 

 braska (59) from Richardson to Cass. 



Black Oak (Quercns vclutina Lam.) is found in the Missouri 

 forests, from which it has moved northward along the eastern 

 border of Nebraska (60) to the Platte River. 



Black Jack Oak (Quercus marilandica Muench.) of the Mis- 

 souri forests, has moved into the southeastern counties of Ne- 

 braska (61), Richardson to Pawnee and Nemaha. 



Laurel Oak (Quercus imbricaria Michx.) is found in the Mis- 

 souri forests, from which it has moved northwestward nearly or 

 quite to the southeastern comer of Nebraska (62). Although 

 this species has repeatedly been reported from this part of the 

 state, I have seen no specimens which were collected within our 

 borders. I have specimens collected in Missouri but a short dis- 

 tance from the southeastern extremity of Nebraska. 



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