HIPPURIDACEAE 149 



1. Myriophyllum spicatum L. Spiked Water-Milfoil. 

 In water in various localities. Kearney; Long Pine; Whitman; Wood 

 Lake. 



2. Myriophyllum pinnatum (Walt.) B. S .P. 

 Lincoln. 



4. HIPPURIDACEAE. 



Hippuris. 665. 

 1. Hippuris vulgaris L. 

 In swamps 25 miles south of Whitman. 



5. ARISTOLOCHIACEAE. 



Asarum. 348. 



1. Asarum reflexum Bicknell. 



In northwestern Kansas and probably in southeastern Nebraska. 



CACTALES. 

 CACTACEAE. 



Stems globose, or ovoid, tubercled, not jointed. 1. Cactus. 



Stems jointed, the joints flattened or cylindrical, not tubercled. 



2. Opuntia. 



1. Cactus. 644. 



Tubercles with 10-20 gray spines, berry 6-8 mm. in diameter. 



1. C. missouriensls. 



Tubercles with 3-8 reddish-brown spines surrounded by grayish ones, 



berry 12-18 mm. in diameter. 2. C. viviparus. 



1. Cactus missouriensls (Sweet) Kuntze. 

 Valentine. 



2. Cactus viviparus Nutt. 



In dry soil in the northwestern part of the state. Alliance; Cherry 

 County; Kearney; Sheridan County; Valentine. 



2. Opuntia. 644. 



Internodes of stem decidedly flattened, 5-20 cm. long. 

 F-lowers yellow. 



Pulvini 18-35 mm. apart, 1-5 spined or spines wanting, fruit pulpy, 

 unarmed or nearly so. 

 Internodes 7-13 cm. long, spines dissimilar, 1-3 or wanting 2-2.5 

 cm. long. 1. O. humifusa. 



Internodes 15-20 cm. long, spines alike, 3-5, 3.5-6 cm. long. 



2. O. tortispina. 

 Pulvini 8-12 mm. apart, spines 8-15, fruit dry, spiny. 



3. O. polycantha. 



Flowers red, pulvini 2-4 spined, fruit, very spiny. 4. O. rhodantha. 



Internodes terete or slightly flattened, easily breaking apart 2-5 cm. 



long. 5. O. fragilis. 



