[APD] Aquatic and/or Non-aquatic Plants

[<jppurchase at rogers_com>]

>From the flurry of recent posts concerning just what is or is not an
"aquatic" plant, or what, if any, distinction should be made with regards to
"aquarium" plants, it looks to me like some people overdosed on chocolate
over the Easter weekend and are just a tad over excited.

Relax people.........its O.K.

This topic is of great interest to me and I have spent much time (and money,
scientific books can get expensive) over the past few years looking into it
for answers. There most definitely ARE definitions used by professionals to
identify plants as aquatic or non-aquatic, and very specific terms attached
to those types of plants. But there are many plants commonly used within the
aquarium hobby which don't fit the scientific definitions for "aquatic"
plants, as well as many which ARE aquatic but are totally unsuitable for our
purposes.

Big deal...

For the most part, we are hobbyists, not professional botanists (with of
course, a few notable exceptions) and we "garden" in our aquariums and
ponds. We will try to grow pretty much anything that will survive and/or
grow on, in, or under water. The operative term here is "grow".  There are
many plants which in Nature find themselves either with wet feet on a
seasonal basis or totally submerged during the rainy season, but will they
"grow" in an aquarium or a pond situation? Many plants will survive
underwater for short periods of time, but they won't do much in the way of
actually growing while submerged. Others may grow slowly but won't flower
and set fruit and/or seed until conditions dry out. Are any of these
aquatic? Probably not, but yet we continue to use some of them successfully
in our aquariums.

I prefer to consider a "true" aquatic plant from the aquarist's perspective
as one which can complete its life cycle while it is either totally
submerged or growing as an emergent with its roots in water.

Christopher D.K. Cook, in his "Aquatic Plant Book", which was written to
cover every aquatic plant in the world at the level of family and genus (he
doesn't get down to the species level in very many cases, except to give the
number of aquatic species within each genus), makes no mention of the Orchid
genus Spiranthes, other than to say that some species can tolerate short
periods of flooding. Kasselmann covers two species of Spiranthes, S.
graminea, from Arizona, Mexico and Guatemala and S. odorata, from the
eastern and southeastern United States. To her credit, Kasselmann uses the
term "marsh plant" for both species and highlights the fact that neither is
truly "aquatic".

I have been familiar with the genus Spiranthes since I was a child growing
up in eastern Canada. My mother used to take me blueberry picking in the
late summer and, as anyone familiar with that plant and its delicious
berries knows, blueberries love to grow on dry, sunny hillsides, not close
to water. I fondly remember seeing the occasional spiral stem of tiny
greenish white flowers, sticking up above the blueberry bushes. My mother
called the plant "Nodding Lady's Tresses", and I have since discovered that
their scientific name is C. cernua, a name used by Kasselmann as a synonym
of S. odorata. The plants which grew in the blueberry fields back home had a
pleasant vanilla-liquorice aroma, and were surprisingly tasty when eaten
with a handful of blueberries (I was a kid, I would eat anything...). But I
never thought of it as an aquatic or marsh plant. Heck, I didn't even know
that it was an Orchid.

Years later, I happened to find a plant for sale in an aquarium store called
"Water Orchid". The salesman told me that it was an aquatic Spiranthes
orchid. I bought it, put it in my aquarium and slowly watched it drown and
die. Oh well, live and learn (at least for me........ the poor orchid on the
other hand wasn't so lucky).

Another plant which has seen use in aquariums, and the object of discussion
here on the APD, is the Red Mangrove, Rhizophora mangle. It is not mentioned
at all in either Cook nor Kasselmann, yet I grew them successfully in an
aquarium for several years until they became so big I had to get rid of
them. Granted, they grew right up and out of the water, becoming miniature
trees with only their roots and lower stems in the water, so their use as an
aquarium plant is limited, at best. But I'd still refer to them as
"aquatic".

So, I don't think its all that important to us as aquatic gardeners whether
or  not a particular plant is considered a "true" aquatic or is simply an
opportunist, capable of adapting to whatever situation it finds itself in.

James Purchase
Toronto


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