180 



2. P. perfoliatus L. 



N. 1115. Pamir, iu the iake Jashil Kul; depth 1—2». Alt. 3800«». Aug. 25. 



1898. 

 N. 1444. Pamir, prov. Wakhan (Ishkashim), in a pond b}- Rang. Alt. 



2700-. 

 N. 2077. Transcaspia, in a fountain \>y Artshman. Sept. 6. 1899. 



var. Muelleri A. Bennett Journ. of Botany XY (1887) 



p. 177. 



This variety is characterized by the short, somewhat acute, 



reflexed leaves. Mr. Bennett has been so kind to send me the 



original specimens from Australia, and they agree perfectly with 



this plant. 



N. 1452. Pamir, prov. Wakhan (Ishkashim), in running water by Nut. 

 Alt. 2700". Oct. 3. 1898. 



— — var. rotundifolia M. K. 



K. 1770. Transcaspia, in running water by Merw. June 3. 1899. 

 N. 1936. Chiwa, in a channel. July 9. 1899. 



3. P. lucens L. 



forma. 



The superior leaves have longer stalks than usually is the 



case, and they are not so membranaceous as the lower ones, but 



as this plant in all other characters agrees with P. lucens, I will 



not refer it to the nearly related form P. Zizii M. K., which is 



perhaps a hybrid. 



N. 2076. Chiwa, in a pond, tonner an arm of the river Amu Daria, by 

 Giaur Kala near the mountain Sultan Baba. Aug. 11. 1899. 



4. P. gramineus L. 



N. 616. Pamir, in a pond by Bordo-ba, by the Alai steppe. Alt. 3500°. 

 June 28. 1898. 



5. P. crispus L. 



N. 127. Tashkent, iu running water by Tshinas. May 7. 1898. 



N. 1138. Pamir, in the lake Jashil Kul, depth 1-2». Alt. 3800"». Aug. 15. 



1898. 

 N. 1143. Pamir, in the lake Bulung Kul, depth 2». Alt. 3800". Aug. 21. 



1898. 



