GENERAL FLORA OF NEBRASKA. 79 



They increase in the number of species towards the western part 

 of the State, their centre of distribution being the Rocky Moun- 

 tains. Other characteristic forms of this order are the Psoraleas, 

 Prairie Clovers (Petalastemon violaceus and P. candidus), Tick- 

 Trefoils (Desmodiums), and Indigo Plants (Baptisia). Baptisia 

 leucophaea, with its large racemes of cream-colored flowers, is 

 abundant, and arrests the attention of every one traveling over the 

 prairies when it is in bloom. The Wild Senna (Cassia Mart 

 landica) is exceedingly abundant and largely sensitive, and full of 

 beautiful yellow flowers is one of the most interesting plants in the 

 State. Still more highly sensitive is the Sensitive Brier (Shrankia 

 uncinata). Its rose-purple flowers are in small heads, and is most 

 abundant in Southwestern Nebraska. 



Of the Rose Family there are fifty-nine species in the State. Of 

 these the wild plums are the most conspicuous. These are found 

 in almost every county, and grow to a size and sj:>read into varie- 

 ties, and attain a richness of flavor rarely equaled elsewhere. The 

 Cinquefoils (Potentilla) are represented by fourteen species. The 

 wild strawberries, raspberries and June berries are all well repre- 

 sented. Of wild roses there are at least four species. Occasion- 

 ally one of these (Rosa blanda) becomes a nuisance, its eradication 

 being difficult from old formerly abandoned fields. 



The Evening Primrose Family (Onagracca) gives many beautiful 

 forms to the State. One of these (CEnothera biennis) which has 

 been successfully reduced to cultivation, is found growing in West- 

 ern Nebraska with flowers three and four inches in diameter. 

 Another one, growing in Central and Western Nebraska, is still 

 larger, but with a low stem, and the flowers light yellow, with 

 orange veins. One of the commonest forms of this order in 

 Eastern Nebraska is Oenothera serrulata. Its flowers are yellow 

 and its leaves narrow and serrulate. All the species of this order 

 increase towards the western limits of the State. 



One of the most curious of all orders is the Cactus Family. Of 

 this order there are in this State twenty species and varieties. 

 Along the eastern counties the commonest forms are Opuniea 

 vulgaris and O. Rafijiesquii. They increase greatly in numbers of 

 species and individuals towards the central and western portions of 

 the State. One of the most beautiful is the Cereus caespitosus. It 

 is of a short cylindrical form, with rose purple flowers two and 

 three inches in diameter. The yellow flower becoming green of 



