Telling Sagittaria from Vallisneria

>    *  To: Aquatic-Plants at actwin_com
>    *  Subject: Frogbit, Java Fern and Aquatic Greenhouses
>    *  From: krandall at world_std.com (Karen A Randall)
>    *  Date: Tue, 6 Feb 1996 15:47:42 -0500
> > A picture on the IFAS site has also made me wonder if a particul
> > was sold as sagittaria something isn't actually "Tape plant" (th
> > strange common names - coon's tail for hornwort), aka Val Americ
> >  I feel so uninformed.  Maybe I've never laid eyes on a real sag
> If you can get your hands on a copy of Neil Hotchkiss "Common
> Marsh, Underwater and Floating-leaved plants of the United States
> and Canada"(ISBN 0-486-22810-X) There are a series of drawings of
> the leaf parts of several Sagitaria and Vallisneria sp. that
> should make it easier to tell them apart. 

I've read of a really easy way to tell distinguish between sagittaria
and val.  Run your hand up and down the edge of a leaf.  If the edge
is smooth, you have a sag.  If you can feel a sawtooth, it's a val.

Don't ask me for the source, I've long forgotten. :-)