280 NEBRASKA STATE HORTICULTURAL SOCIETY. 



Eriogonum annuum) which, with its slender, gray flowering stems and 

 conspic-uous flat-topped clusters of flowers, occurs as widely scattered 

 individuals here and there, or may occasionally form rather dense com- 

 munities; spiderwort (Tradescantia virginica), tufted hymenopappus 

 (Hymenopappus filifolius), purple blazing star (Lacinaria squarrosa), 

 lance-leaved psoralea (Psoralea lanceolata), western thistle (Carduus 

 plattensis), rough sunflower (Helianthus scaberrimus), prickly poppy 

 (Argemone intermedia), painted pod (Phaca longifolia), green milliweed 

 (Acerates virdiflora), switch grass (Panicum virgatum), prairie pink 

 (Lygodesmia juncea), Geyer's spurge (Euphorbia geyeri), yellow evening- 

 primrose (Oenothera rhombipetala), sweet pea (Lathyrus ornatus), and 

 hairy golden aster (Chrysopsis villosa). All of these plants occur as 

 scattered individuals except the painted pod and prairie pink, which 

 are often gregarious. They all show striking anatomical characters that 

 doubtless aid in their survival in such dry soils, exposed to such trying 

 climatic conditions. 



In addition to the grasses and the common herbaceous associates 

 the vegetation of the upland is rich in species of low shrubs. In many 

 restricted localities these under-shrubs compose the bulk of the vegeta- 

 tion and really rival the bunch-grasses in dominance. Among these 

 low, much branched, woody plants. New Jersey tea (Ceanothus ovatus), 

 Bessey's sand cherry (Prunus Besseyi), poison ivy (Rhus radicans), 

 and the prairie clovers (Kuhnistera purpurea, K. villosa, and K alba) 

 are among the commonest and most widely distributed. All of these 

 plants are dwarfed, much branched shrubs often growing in communities. 

 New Jersey tea is found most frequently near the tops of the hills on 

 north facing slopes, where the dense, light green patches from ten to 

 seventy feet across contrast very greatly with the surrounding bunch- 

 grass vegetation. Bessey's sand cherry is one of the most ubiquitous 

 plants of the whole region. It is found in almost every site of the up- 

 lands and with its low, short twigs with tufts of glossy green leaves is 

 seen springing from the sand on practically every hill. Very frequently 

 it forms extensive communities. The fruit of this species Is an impor- 

 tant food for the homesteaders in many localities. The prairie clovers 

 seldom form well-defined communities, but they occur as more or less 

 scattered individuals, especially on the lower slopes of the hills adjacent 

 to the larger valleys. 



The most striking habitats of the uplands are the "blow-outs." 

 Blow-outs are conical or rounded depressions of varying depth and 

 diameter formed by the blowing of the sand and vegetation from cer- 

 tain spots on the upper slopes and crests of the hills. The rim of the 

 more or less conical depression is sometimes almost circular, but it is 

 usually irregular with a general circular outline. Since the prevailing 

 winds of the region are from the west, and since "blow-outs" are the 

 direct products of wind action, these peculiar structures are mostly con- 

 fined to the west sides of the hills. The greatest number occur on the 

 northwest-facing slope, but they range in position from northwest to 



