Deformed Echinodorus bleheri?
by Neil Frank <nfrank/mindspring.com>
Date: Mon, 22 Feb 1999
>From: Erik Olson <
[email protected]>
>On Sat, 20 Feb 1999, Andy Dilbert wrote:
>
>> I recently bought some "Amazon Sword Plants - Medium sized" from Aquarium
>> Driftwood. They have very long stems, approximately 30 cm. long, and
leaves
>> that are only about 10 cm long. Are these normal Amazons (Echinodorus
>> bleheri) that were just grown in ill-lit tanks, or are these another
>> species? I wish my plants had longer leaves and shorter stems, like the
>> Amazon's in the following pictures. Can I make my plants change?
>
>Why yes! The magic ingredient is... water. Most amazon swords are grown
>emersed, out of water, and as such have the leaves you see. It's easier
>for the growers, and the plants are more easily transported to the
>wholesalers and dealers. Once kept underwater in the aquarium, they will
>begin reverting to the submersed leaves you want.
Because most if not all Echinodorus these days are grown emersed, Erik is
probably correct. However, there are commercial sellers who buy plants
from the nursery and grow their plants out underwater for a variety of
reasons. The nursery may do this themselves. So, Andy may have purchased a
swordplant with submersed leaves. Andy, there is still hope....
Some Echinodorus change the shape of their leaves in response to day lenght
(photoperiodism). These are the so-called short day plants and long day
plants... these are the ones that come from temperate and sub-tropical
latitudes. Not all plants come from the equator. In fact, many Echindorus
come from the southern part of South America or the Southern U.S. So, a
underwater plant which is grown outside during the winter in the southern
US will only be getting ~8 hours of good light. One of the Echindorus
described in the literature is E. parviflorus (black amazon swordplant).
There is also the Tropica hybrid with its hammered leaves. It is a short
day plant. Muhlberg writes: "In long day period it develops water leaves
with short petioles and rather long blades. In short-day periods the leaves
change considerably, petioles become longer and leaves more compact." This
sounds like the plant Andy described. I have not seen anything written
about bleheri and have not personally experimented with it.
Most aquarists keep their lights on for a 12-hour cycle. If you increase
the daylength from 8 to the "normal" 12 hours, the plant leaves will change
for the photo-period-sensitive plants . This is not necessarily because the
new plant is changing from emersed to submersed leaves. Even those of us
with established plants grown for a while with 12 hours might see changes
in the stem/leaf ratios when increasing to 15-16 hours of lighting. Just
another one of those unending amazements about growing aquatic plants. Who
says freshwater aquarium keeping is boring. Reefkeepers, eat your hearts out!!
