Subject: NANFA-- Christmas moss

Jeffrey Fullerton (
Sat, 10 Feb 2001 22:15:44 -0500

> Subject: NANFA-- Christmas moss
> RE: Red shinner thread/
> Sorry about my ignorance, but what is the Christmas moss?
> Can you tell the scientific name, please? Looks like a native species.
> I always been interested in aquatic moss (besides the ubiquitous
> tropical Vesicularia dubyana) and I am wondering if this Christmas moss
> is a Fontinalis or Amblystegium species.
> Anyone knows how many native, fully aquatic moss species are in US?
> Thanks
> sorin

The two most common varieties in the US known to aquarists and water
gardeners are species of Willow Moss- Fontanalis. I have Fontanalis
antipyretica which us the larger of the two and has very dark green
scale like leaves and grows in long flowing masses in some streams
locally. I've seen it even more abundant in intermittant streams in
northern Virginia where it often blanketed the clay bottom and grew as a
terrestrial form when the streams dried up in the summer and late fall.
Elsewhere I usually find it less abundant and usually grows on rocks or

F. antipyretica - aka the 'Incombustable Moss' so named for its fire
retardant properties when it was once used as a filler material for
whatever in days of old. I never have much luck with it in a tank but
outdoors it fares better.

Perhaps the best one for inside is F. gracillis (possibly the same plant
as F. decalaria) - not sure of the official common name but I call it
the smaller Willow Moss! Much finer in habit closer to Java Moss of the
aquarium trade and sometimes sold. Very wide range - I have collected it
locally and in a stream near Gulf Hammock Florida and last summer with
Ray in Wisconsin! It holds up much better than F. antipyretica in the
aquarium and I've used it sometimes in jars for raising pygmy sunfishes
, salamander larvae and Broken-striped Newts!

In my pond and watercourse I grow both species by tying them onto peices
of waterlogged driftwood which I strap onto a brick or rock and sink to
the bottom. Great spawning medium for fish. Also have a thick mat of F.
antipyretica on top of the lava rock in the biofilter at the head of the

One problem with willow mosses is that they accumulate algae. Since I've
seen the smaller variant growing in full sun in the wild I am sure it's
related to the problem I've had with milfoil. Related to my water since
the wild plants were free of algae. A temporary remedy is to move the
moss along with its holdfast to a shady location for a while or even
grow them terrestrially in the shade for a while. Out of water the moss
converts to a greenish fuzz that thightly hugs the log or stone and
quickly reverts back to long flowing strands when returned to the water.
This is sort of like the way the stuff in Virginia used to grow.

There is another species which grows in cold springs and streams in our
mountains. The name I do not know but it is has even bigger scales than
larger of the two previous species. I don't mess with it because it is
not likely to survive in a tank without a chiller!


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