Re: Rotala macrandra and Name that Plant

In Reponse to John and Todd.....

>From: John Lobingier <jlob at wpa_net>
>Date: Wed, 12 Jun 1996 14:53:56 GMT
>Subject: Re:  Root Bound Substrates
>Hi Neil Frank, I took notice of your post because of the Rotala Macrandra.
>This is a plant I want to add to my tank.  I thought it like other red
>plants it needs a lot of light?  I am confused to see it in a 70 gal. low
>light tank with crypts doing well.  And, a tank in which the swords died off
>and the Rotala Macrandra thrived.  I would have thought the swords would
>have thrived and the Rotala dwindled.  If I am confused here please tell me.
>I want to try Rotala Mac.  and hope you can tell me a thing or two about it
>in order for me to have success with it.  Thank you.
>There are always exceptions to the rules.
>>From: tmarch at primenet_com (Todd March)
>Date: Wed, 12 Jun 1996 23:23:02 -0700
>Subject: Rotala macrandra...?
>Neil Frank, on June 11, 1996 said:
>>This may explain why crypts (6-7 differrent species) have completely taken
>>over my non-CO2 injected, low light, 70 gallon peat substrate tank after 5
>>years. The only other plant that is doing well is Rotala macrandra.
>It was my understanding that Rotala macrandra was something of a prima
>dona--light loving, picky about substrate conditions (didn't someone
>recommend potting r.macrandra--ala Karen Randall--not too long ago...?).
>Perhaps you could give us further information on your tank, and your
>experience with this red beauty, Neil...?

Firstly, John is absolutely correct.... "There are always exceptions to the
rules." My guess is that many plant books are written by someone who only
tried growing a plant under one set of conditions, or has rewritten what has
been published elsewhere.  We should strive to experiment and try different
plants in different situations. I have found that macrandra will do OK with
low to moderate light, but does better with brighter light. I am color
blind, so I can't tell you how the color improves with more light <g>. I
have experimented with other green/red plants and have noticed that lighting
does affect when they turn from green to red (e.g. Ludwegia sp.) I WOULD BE
LIGHTING INTENSITY OR SPECTRUM. I suspect that blue light is important. 

I have only tried to grow macrandra it in a limited number of situations,
but have found that it will grow well in a peat substrate with moderate
light and without CO2 injection. I think the low pH and organic
decomposition from the peat provides all the C and other nutrients needed by
the macrandra. It doesns't hurt when I supplement with trace elements. The
other set up is the use of soil in a higher light, CO2 injected tank with
weekly trace element fertilization. In this tank, it does better and
develops the beautiful large leaves. In both tanks the leaves get larger as
they approach the surface and the best growth when they drape across the
surface. As Karen and others have mentioned, it may need the soil or
equivalent to give it that 'something' else. Perhaps all of the Dupla
worshippers should realize that the drops and the tabs might not be enough
and the duplagen might be providing the missing ingredient with some plants.

Regarding the chain sword, I was talking more about the changes in an old
tank. Macrandra seems to be immune to the allelochemical or substrate
changes which caused the crypts to outcompete the Echinodorus species. I had
had a nice bunch of Mayaca fluviatillis growing for years, but as the cryts
started to multiple this past year, the Mayaca started to decline. (G.Tong:
I think this is one on  page 24 of Amano's book, Nature Aquarium World which
you wrote 'there's a plant in the background that I have but can't name.
It's the long stringy green plant
with short spiky leaves that is curving toward the center of the photo.')

This is another point to remember.... the age of the tank, the relative
crowding, the number and type of plant species sharing the substrate and
many other factors can affect success.

By the way, this plant is sometimes labeled macranthra. I think a plant farm
or distributor with a lisp started this years ago <g> and distributors have
kept the name going.


Neil Frank, TAG editor    Aquatic Gardeners Association    Raleigh, NC USA