622 REPORT OF STATE GEOLOGIST. 



P. PUdiLLUS L. Small Pondweed 



In sluggish streams and shallow waters throughout the State. 

 Not abundant in any of its stations. 

 Flowers in July and August. 

 Gibson (Schneck). 



P. DIVERSIFOLIUS Kaf. 



(P. hybridus Michx.) 

 In many parts of the State in ponds and swamps. Quite abund- 

 ant in the stations in which it occurs. 

 Flowers from June until September. 

 Vigo (Blatchley) ; Lake and Laporte (Hill). 



P. Spirillus Tuckerm. 



Reported from the southern part of the State, but doubtless to be 

 found throughout our area in ponds and sluggish waterways. 

 Flowers from June until August.' 

 Vigo (Blatchley). 



P. pectinatus L. Fennel-leaved Pondweed. 



Found in the Wabash River in various parts of its course, more 

 plentifully in its lower stretches. 

 Flowers in July and August. 



P. interrupted Kitaibel. 



In the northern part of the State in shallow, still or sluggish 

 waters. 



Flowers in July and August. 

 Lake (Hill). 



P. Robbinsii Oakes. 



In the northern part of the State in shallow waters of lakes and 

 in swamps. Added to the flora by Rev. E. J. Hill. 

 Flowers in August and September. 

 Lake (Hill); Steuben (Bradner). 



ZANNICHELLIA L. 



Z. palustris L. 



Collected from a single locality near Terre Haute. The station 

 was a pond south of a blast furnace. The pond rarely froze on ac- 

 count of the warm stream of water flowing into it from the furnace. 

 Detected first in 1886 and its continuance noted until 1893. At 



