Steve,

Here's a more complete description of the cattail activities
I like to do at that cattail stand by the Marmo dam.  I never
had time to do all of these, but they can provide some useful
tie-ins to many of the wetland topics.

Did you get a good look at the baby turtle the students found
Thursday?  I recall it had lines around the eyes, some red
around the carapace, and a red mark on the plastron, must be
a Midland Painted Turtle?

* Yank out a dead stalk by the rootstock.  Sometimes this can
  be hard especially if the soil is dry.  Of course explain
  this is for study and we don't want everyone yanking out
  plants by the roots.  Explain cattails can reproduce 
  vegetatively via the underground rhizomes and form colonies.

* Have students smell the soil attached; the rotten smell is
  indicative of hydric soil: the soil is waterlogged and low
  in oxygen, resulting in slow decomposition (can talk about
  decomposers at this point) and accumulation of partially
  decomposed organic material.

* Examine a seedhead, preferably one that is still intact and
  looks like the fluff has been tied together by invisible
  strands of silk.  Plants are producers and these seeds are
  yet another source of food for animals.  Show the downy
  parachutes that aid in dispersal.

* Carefully open the fluff and look for the caterpillar that
  had spun the silk threads to keep its home from breaking
  apart through the winter.  This is the cattail moth that
  uses the seedhead for insulation and protection, as well
  as for food.  It's small and pale and not easy to find,
  but I have failed to find one only once in about 5 tries
  so far; most of the time we find more than one.  If you
  do not find one, perhaps lay the fluff aside in a plastic
  bag and examine later; they may crawl into better view
  over time. In late spring they may pupate and become even
  harder to find.

* Feel the stem: soft and spongy.  The air channels (spongy
  aerenchyma) in the stem (and leaves - have them feel a
  thick leaf if possible) are a special adaptation to the
  low exygen levels in hydric soil: the plant can transport
  oxygen produced in the leaves (refresh photosynthesis) to
  the roots.

* Cut the stem into several segments (small scissors are
  good for this) for use as a first activity after students
  have filled their trays with water: put the stems (and
  leaves if any) in the water and squeeze out the air; they
  should bubble out, showing their role in oxygen
  transport.  This keeps students busy while the guide
  performs the initial dips.

Peter