288 



PONTEDERIACEAE 



Heteranthera 



"TO 



Map 597 



Heteranthera reniformis R.& P. 



50 



Map 598 



Heteranthera dubia (Jacq) MacM. 



0" 5o 



Map 599 

 Juncus effusus L 

 var. s&Jutus Fern. & Wieg. 



1. Pontederia cordata L. Pickerelweed. Map 956. This species is fre- 

 quent throughout most of the lake area but is absent or very local south 

 of it. It must have its base in water most of the time, but otherwise it 

 does not seem particular as to where it grows. It seems to grow nearly as 

 well in almost pure marl areas as in sandy, muddy, and mucky borders. 

 However, I find the largest specimens in mucky borders of lakes. The 

 trimorphic flowers of this species are interesting to one who can give the 

 time to their study. 



N. S. to Minn., southw. to Va. and Tex. 



la. Pontederia cordata f. latifolia (Farw.) House. This form, in the 

 extreme, is well marked but our specimens seem to intergrade so much 

 that it is a question whether the two forms should be maintained. The 

 range is the same as that of the species. 



115. Pontederia cordata f. angustifolia (Pursh) Solms-Laubach. This 

 form is distinctly marked but I am not certain that another form may not 

 be on the same rhizome. On the low, marly shore of the southeast side of 

 Simonton Lake, Elkhart County, I made a study of this form. I found it 

 farther out in the lake in a zone of water a little deeper than where the 

 species grew. The species grew in a dense stand while the form was not 

 so dense. I did not realize, until recently, the significance of this form 

 although I have found it in several counties. Rather rare in Indiana. 



P. E. I. to Wis., southw. to Ind. and southeast of the Appalachian Mts. 



924. HETERANTHERA H. & P. Mud Plantain 



Leaves reniform; flowers white or pale blue 1. H. reniformis. 



Leaves linear; flowers yellow 2. H. dubia. 



1. Heteranthera reniformis R. & P. MUD PLANTAIN. Map 597. Very 

 local in ponds in the southern counties. I have found it on the muddy shore 

 of Hovey Lake, Posey County and elsewhere in natural and artificial ponds. 



