Re: native plants
A large part of the work I get has to do with collecting and identifying
native, north temperate aquatic plants. They would, by and large, make
excellent aquarium plants. The best way to collect them is to wait for
dormancy in the fall and collect the overwintering structures. In many
cases these would be tubers found underground, often they are
mucilagenous turions (telescoped stems), and in rare cases even seeds.
All of these structures are easy to clean. One of the more interesting
species IMHO is Isoetes, or quillwort. This is a fern which produces
spores at the base of each leaf. When the leaf dies, the spores are
released and readily form baby plants if both mega and mirco spores are
present. This plant may be a challenge, however, as it uses its roots to
get CO2 and must therefore be grown in a fairly fertile substrate.
Of course, if you are in karens neck of the woods, you could always drop
in at the New England Aquarium and see the display tanks of native plants
that she helped set up (I have yet to win the lottery so, though eager,
have not seen them myself).