Grool, Roots, Etc.

---------- Forwarded message ----------
Date: Fri, 14 Jun 1996 13:01:04 -0400
From: krandall at world_std.com (Karen A Randall)
To: Aquatic-Plants at actwin_com
Subject: Help, Grool and Roots

Subject: plant help.....

> While most of my plants are doing well (hygros, crypts, crinums,
> Barclaya, and several stem plants etc.), I seem to be having a p
> specifically with three large Amazons and several Apon. Crispus.
> Crispus are blooming and putting out shoots to the surface of th
> but their leaves are steadily turning brown and/or transparent. 
> Amazons are also developing yellow margins which gradually consu
> leaf until I have to remove it.  This isn't for lack of iron, as
> fertilize with Seachem's Flourish as directed on the bottle and 
> added several laterite balls in the substrate.  It appears as th
> are being burned (as an outdoor plant would do if left to dry ou
> sun).

First, just because you are using a supplement "as directed" 
doesn't mean you are not deficient in trace elements.  Not all 
trace element mixes are created equal, and every tank has it's own 
specific needs.  Believe your plants if they tell you they are 
deficient in some area.  

That said, I don't think that's what is wrong with your plants 
either.  What you describe sounds exactly like what happens to the 
emersed growth on commercially grown Echinodorus sp.  As long as 
they start to produce submerged leaves, don't worry about it.  At 
2 1/2 weeks, your plants are just barely starting to settle in.
> I also have a problem with several vallisnaria spec. - the leaf 
> about half way up to the tip - are going "soft" and transparent.
> have been planted correctly with the crown of the plant above th
> substrate, yet I can't seem to stop the progress of these "melti
> leaves.

This is also a very common reaction to shipping and transplanting. 
 If the conditions are suitable for Vals, you should see new 
growth soon.  You well still probably eventually lose the 
"melting" leaves.

> As for my lighting set-up, I currently run two 40-watt vitalites
> hours daily, with a 4300k metal halide running from noon until 5
> Tank temp. gets to about 80 - 82 degrees, but I am running a fan
> control this.  Substrate is 2 - 3 mm in size and about  3-1/2 in
> deep.

You don't mention supplemental CO2... With that much light, you 
really need it. (Although, again, that's not what's wrong with 
your plants in this instance)

Subject: Re: Bluegreen algae and the Grool

Stop, Paul!!! You're giving me nightmares!!!<VBG>

Subject: Why do roots exist?

>  According to our speaker this evening
> aquatic plants absorb most nutrients from their foliage and have
> for a major root system with root hairs, etc. the wat terrestria
> do.  Why then, do plants which could be "floaters and drifters" 
> put out a thousand roots at every node?

Because your speaker was not wholey accurate.  _some_ plants feed 
only from the water column, some feed mostly from the substrate, 
and most are somewhere in between.  If a plant can grow in an 
emersed form (as Hygros do) it is highly unlikely that they feed 
_completely_ through their leaves.  

I can't speak with any first hand experience about Elodea, since 
I've never worked with it.  But I _belive_ this is a fully aquatic 
plant who's roots are mainly used as hold fasts.

> 2. Is this mysterious factor (that causes my hygrophila to decid
> produce pounds upon pounds of roots) related to the decision a p
> makes, on whether to bud/produce offspring rather than grow into
> plant? For instance, under some circumstances, water sprite/wist
> produce a large "vegetative" body, and under other circumstances
> plants will appear at almost every nook in the plant leaves, and
> parent plant will disintigrate and die.  These events are so mys
> me that I'm tempted to create a religion to explain them!!

Wait a minute!  Water Sprite (Ceratopteris sp.) and Water Wisteria 
(Hygrophila difformis) are to _very_ different plants!  What you 
are describing sounds like Water Sprite (actually a fern).  In my 
experience, if Water Sprite can get itself out of the water, it 
will grow to be a very large plant.  If not allowed to reach the 
surface, eventually it produces huge quantities of babies, and the 
parent plant dies.

Water Wisteria grows like any other Hygro.  It is a "stem" plant, 
and will flower if allowed to grow emersed.  It does not produce 

> 3. The success of liquid supplements would seem to suggest that 
> claim is true - that plants can absorb nutrients through their f
> and don't depend on roots for that - that perhaps roots are chie
> to help anchor the plant.

Remember that liquid nutrient supplements are drawn down into the 
substrate where they bind to cation exchange sites to be used by 
the plant roots.  This is one of the main purposes of substrate 
heating, but it happens in any tank with a substrate will filled 
with the roots of healthy growing plants.

>  How does this claim rest with you all
> is a reasonable statement, why is substrate that important - why
> with laterite/soil etc. when you can just grow plants in gravel 
> supplement the water with nutrients?  

Again, it depends on the plant.  Java Ferns, for instance, are not 
at all dependent on a substrate for nutrition, and will grow 
equally well in a bare tank. (Hornwort falls in this category too) 
Echinodorus sp, and Cryptocorynes are the total opposite end of 
the spectrum, and _will not_ thrive without a rich substrate. 
(this can be anything from a substrate specifically set up for 
plants or an old "plain gravel" substrate enriched by fish waste 
over a period of time)  Most plants fall somewhere between these 

> I'm just curious, but thes
> statements just don't seem to mesh with everything I've learned 
> Other members of my club swallowed these claims quietly though, 
> why I'm bringing ithem up here. Thanks for any ideas you might h
> this.. 

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA