ENGELMANN THE GENUS ISOETES IN N. AMERICA. 361 



1875. G. D. Butler discovered in the Indian Territory the spe- 

 <;ies named for him I. Butleri, and with it a new locality for 

 /. melanopoda. 



1878. C. G. Pringle found in Lake Champlain the form of /. 

 echinospora^ which I have designated as var. robusta. 



1879. M. E. Jones met with /. Bolanderi in Utah. 



1880. A. Gattinger discovered near Nashville, Tennessee, a 

 /. Butleri^ var. immaculata. 



1881. I collected /. lacustris var. paupercula in Grand 

 Lake, Middle Park, Colorado, and C. G. Pringle found the same 

 in Northern California. 



2. PUBLICATION. 



1753. Linneeus published in his Species Plantarum, ed. i., his Isoeles 

 lacustris, the only species known to him. 



Neither Michaux nor any of the older writers on American 

 plants knew of any North American Isoetes. 



1816. Pursh, Fl. Am. Sept. ii. 671, mentions " /. lacustris" 

 from Oswego river, Western New York, which is most probably 

 /. echinospora, var. Braunii^ the only species thus far known 

 from that region. 



1818. Nuttall, Gen. ii. 253, has "/. lacustris'' from the miry 

 shores of the Delaware near Philadelphia, which cannot be any 

 other than /. riparia ; he also gives Pursh's habitat. 



In the same year Barton, Fl. Philad. ii. 213, has "/. lacustris" 

 from Philadelphia, which may include both /. riparia and /. 

 Engelmanni. 



1S24. Elliott knows no Isoetes. 



1S26. Torrey (Comp. Fl. North. & Middle States) gives as 

 habitat of "615, /. lacustris" bottoms of lakes, evidently without 

 having himself seen it. 



In the Flora Cestrica of the same year Darlington does not 

 mention the genus. 



1827. Sprengel, Sjst. Plant, iv. 9, knows only /. lacustris with three 

 •varieties. 



1833. Beck in his Botany repeats Pursh's and Nuttall's lo- 

 calities. 



1840. Hooker, Fl. Bor. Am. ii. 268, mentions " /. lacustris'' 

 from the Saskatchawan. This may be the true lacustris or a 



