Hard to tell from those pictures. If you crush it in your hand does it smell like a skunk?

http://aquaplant.tamu.edu/plant-identification/alphabetical-index/muskgrass/


www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).