1896.] Botany. 59 



The Flora of the Sand Hills of Nebraska.— Mr. P. A. Ryd- 

 berg has recently published in the Contributions from the U. S. 

 National Herbarium (Vol. Ill, No. 3) the results of his careful explor- 

 ation of the Sand Hills of Central Nebraska in the year 1893. Two 

 or three counties in about the center of the sand hill region were 

 selected as the ground to be thoroughly studied, and three months were 

 given to this limited area. Two streams transverse this area, the Mid- 

 dle Loup River and the Dismal River. The former is a rapid stream 

 running down a slope of 8} to 13 feet to the mile, with hills from 200 

 to 300 feet high on each side of the rather wide valley (i to 1 h miles). 

 In its narrower portions the valley is filled with lagoons and swamps, 

 the remains of old river beds. The Dismal River runs through a nar- 

 rower valley, and the bluffs are higher, ranging from 300 to 600 feet. 

 Away from the rivers Mr. Rydberg found three kinds of sand hills, 

 the first of these are called by him the " barren sand hills," not be- 

 cause they are without vegetation, for they are not, but because they 

 are at present of very little use to man. Here one finds the true Sand 

 Hill vegetation, and when seen from the higher points " the hills ap- 

 pear likes the billows of the ocean." 



The Dry Valley Sand Hills constitute the second kind. The hills 

 are long ridges running mostly east and west with long valleys be- 

 tween. The underground drainage is so perfect that little or no water 

 gathers in the valleys, but their rich soil readily yields good crops, or 

 excellent pasturage. 



The Wet Valley Sand Hills differ from the last in the greater abrupt- 

 ness of the ridges, which are, in fact, sometimes impassable, and in the 

 less perfect drainage, ponds of water generally occurring at the easterly 

 end of the valleys. In no case is there " surface drainage," every pond 

 being destitute of an outlet. About these ponds grasses grow luxu- 



It is evident that the Sand Hill flora is not a homogeneous one. The 

 plants growing along the rivers and about the ponds are very different 

 in character from those which occur on the wooded summits of the 

 " barren sand hills," or the steep slopes of the hills which border the 

 dry and wet valleys. In summing up a discussion of the matter, Mr. 

 Rydberg says: "The most characteristic plants of the sand hills are 

 the four blowout grasses, Cakunovilfa lotxjifolia, EragrortL* tenuis, Red- 

 fieldia flexuosa, Muhlenbergia pungens, of which the first two are found 

 on nearly every sand hill. Next to these the following are the most 

 common or characteristic herbaceous plants: 



