# Chain sword article from PAM, Issue #1 & 2



## nfrank (Jan 29, 2005)

The question about tenellus made me remember that I have an on-line version of the _*Planted Aquaria Magazine *_ chain sword article, put out by Gomberg in the spring of 2000. Now, APC members can see the entire article including the errata that was published in the hard-to-find long out-of-print issue #2. The article includes several pictures of _E. tenellus._ as well as emersed and submersed forms of other shain sword species.

http://www.aquatic-gardeners.org/Chainswords-NeilFrank.htm

At the time of this article, I had not kept _E. Echinodorus angustifolius_. I will soon be getting some of this sword which is reputed to be the tallest chaining sword


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## Cavan Allen (Jul 22, 2004)

Thank you Neal! It's an excellent article and I wish we saw more like it. It's good to see you're still around.

Have you see the sword circulated as _Echinodorus sp_. 'Sao Paulo'?

Lastly, what do you make of this? I haven't looked into it much myself. 
http://www3.interscience.wiley.com/journal/119405254/abstract


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## nfrank (Jan 29, 2005)

Cavan,
Yes, i am still around! Currently in the process of setting up new tanks, following my move to different house back in Feb.
I tried your link to see the article, but could only view the abstract. Anyway, it looks like it will be over my head.


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## Robert Hudson (Feb 5, 2004)

Somebody from Europe over on Planted tank.net posted that E. tenellus and all its variants and other grass like species have been re classified under a whole new genus outside of Echinodorus, and quoted the study. Know anything about that Cavan, or Neal? Neal, I havn't seen you anywhere on the internet in long long time! Still have any Japanese pearl grass?

If this is true, it makes gombergs article really out of date!



> I thought these chain-forming species were now in Helanthium? So these are Helanthium tenellum now regardless of their form?


Thats what I was talking about... good to know my memory is still working


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## miremonster (Mar 26, 2006)

Yes, Samuli Lehtonen (Univ. Turku, Finland) researched in his PhD thesis the phylogenetic relationships of Echinodorus and many other Alismataceae by analysis of molecular and morphological characters.

An own genus Helanthium makes sense, because the chain swords not only differ distinctly from the other, "big" echinodoruses, but also don't form a natural group ("monophylum") with them, and are instead closer related to the african / asian genus Ranalisma.

The odd species Echinodorus nymphaeifolius from Central America is far from Echinodorus and Helanthium and has now its own genus: Albidella nymphaeifolia.

Daniel*Swords, a friend of S. Lehtonen, writes about the taxonomic changes: http://www.plantedtank.net/forums/g...sion/49575-runner-growing-swords-renamed.html


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## nfrank (Jan 29, 2005)

i have not been following the taxonomy literature. Thanks for making those comments. I did some quick internet searches and find mention of this genus as a synonym:

e.g. see http://en.wikipedia.org/wiki/Echinodorus_tenellus

Due to the nature of latin,the corresponding name is Helianthium tenellum. Note the spelling of the genus.

It is not clear, however, if it is an "officially" accepted change. For example see ITIS
http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=514569

I checked the plantedtank.net and searched on Helianthium and Helanthium and nothing came up. See if you can find the link. Maybe someone also should look into the paper mentioned by Cavan.

Regardless, i think that name changes add unnecessary confusion to us hobbyists. When a name does change, i wish that the synonyms are carried with the new name.
--Neil


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## Cavan Allen (Jul 22, 2004)

I don't have a problem with names being changed if it's warranted, but I too am unsure if this has really been accepted by many or not. For that reason, I've not yet changed the PF entries. It's on my list of things to research, and I'll be back with more if I find something.


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## miremonster (Mar 26, 2006)

nfrank said:


> ... _E. Echinodorus angustifolius_. I will soon be getting some of this sword which is reputed to be the tallest chaining sword.


There's a problem...
I've got the Echinodorus "angustifolius" from Tr*pica, and under similar conditions it remains clearly shorter than the "real", "old" E. angustifolius, cultivated by European aquarists for decades, reaching 40 cm and more.
Like the real E. angustifolius, the E. "angustifolius" from Tr*pica belongs to the E. bolivianus (Helanthium bolivianum) group. In my tank it was mostly 10-15 cm, at maximum 30 cm high, the leaves 3-5 mm broad, the plant looking like kinda giant light green E. tenellus (but I'm sure it isn't E. tenellus). Emersed flowering plants are very similar to emersed E. latifolius (another form of E. bolivianus), submerged plants ditto, differing only by narrower leaves.

Pics:


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## nfrank (Jan 29, 2005)

5-6 years ago, i received a "E.angustifolius" from Claus Christensen at Tropica. It also remained relative small, like miremonster shows. In fact, it resembled E.bolivianus that I already had and which came from a US grower. 
The E.angustifolius that I await is coming from directly from Oriental in Singapore. It will be interesting if it is different than the plant propagated by Tropica and achieves the 40cm growth which i would like to see. (BTW, whats with the spelling with * ? Is that something like pl*co?)

In the aquarium hobby the trade name together with its source may in fact be more important than the most current and apparently correct latin name.This way hobbyists can more easily compare their plants. While the nursery which grows the plant is not the same as knowing its original collection location, this information can help distinguish one plant from a very similar one. This is certainly true among Crytocoryne, where many hobbyists add a number suffix to the species name (indicating its collection location or other source) to distinguish one potential variant from another.


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## nfrank (Jan 29, 2005)

Here are some important clarifications provided to me today by Samuli Lehtonen, the author of the _Cladistic analysis of Echinodorus _article:

" It always takes time before new names (in this case actually very old 
name was re-validated) become in wider use. My paper was published 
early this year so no wonder if the name is not yet in general use. 
However, since Helanthium's are not even closely related to 
Echinodorus (and classification should reflect the genealogy), it 
would be extremely misleading to call them as ]Echinodous. I also
note that the original (and thus legitimate) spelling of the genus 
name is Helanthium (=swamp-flower). The name was misspelled about 100 
years ago as Helianthium (=sun-flower), and unfortunately, mostly the 
incorrect spelling has been used ever since."


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## Robert Hudson (Feb 5, 2004)

> Regardless, i think that name changes add unnecessary confusion to us hobbyists. When a name does change, i wish that the synonyms are carried with the new name.


I agree with that statement 100%. It can be confusing, and somewhat pointless, and all but a minority of hobbyists do not care. It is good to be able to accurately indentify each plant, but when it becomes ambiguous its just ackward. And old names stay around for a long long time.



> There's a problem...
> I've got the Echinodorus "angustifolius" from Tr*pica, and under similar conditions it remains clearly shorter than the "real", "old" E. angustifolius, cultivated by European aquarists for decades, reaching 40 cm and more.


Is it not a well accepted fact by now that all plant species can vary greatly in size, shape and even color to varying degrees? A while back I got a ton of E. bolivianus from Paul K. and it was quite tall. It grew out in my tanks half the size of the original plants.



> Following Lehtonen (& Myllys), the species names are:
> 
> E. bolivianus -> Helanthium bolivianum
> E. tenellus -> Helanthium tenellum
> ...


They can't even agree on the spelling, and its not the first time for that either


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## HeyPK (Jan 23, 2004)

Is Helanthium the genus name for all the grass-like ones with runners? I am also very curious to know if _E. uruguayensis_ has been split up in the new taxonomy. I am a firm believer that it should be. The red and green horemanii plants are a lot different from the narrow-leaved plant that can produce floating leaves.

I thought I had _E. angustifolius_, but it has always been indistinguishable from _E. bolivianus_. The E. vesuvius form of angustifolius is being sold a lot these days, but the unmodified wild type is really hard to get. Hope you get some, Neil!

I usually prefer the wild types to the modified types. I never liked the Tropica variety of _E. parviflorus _ which looks like it has some kind of nutrient deficiency. I still have a few plants of the wild_ E. parviflorus_ in a jar on the windowsill.


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## nfrank (Jan 29, 2005)

Hey Paul!
I clearly have been distant for the past 5+years, but hope to remedy that situation. Do you still have your long, narrow leaf _E. uruguayensis_? I now have a 24" deep tank and would love to see it growing side by side next to my Gasser red and green horemanii. 
-Neil


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## miremonster (Mar 26, 2006)

S. Lehtonen's PhD thesis is published as a book, consisting of 4 papers: Lehtonen, S. (2007) Natural History of Echinodorus (Alismatceae).- Annales Universitatis Turkuensis, Sarja - Ser. AII Osa - Tom. 203. But in the newer paper(s) from 2008 (I haven't read them) is further information, e.g. description of 2 new species.

@nfrank:


> BTW, whats with the spelling with * ? Is that something like pl*co?


I didn't know if it could cause any problems when writing a whole company name... because of product placement or so...8-[ 



> In the aquarium hobby the trade name together with its source may in fact be more important than the most current and apparently correct latin name.This way hobbyists can more easily compare their plants. While the nursery which grows the plant is not the same as knowing its original collection location, this information can help distinguish one plant from a very similar one. This is certainly true among Crytocoryne, where many hobbyists add a number suffix to the species name (indicating its collection location or other source) to distinguish one potential variant from another.


I agree completely with You! I wish there was as much collaboration among hobbyists and botanists interesting in Echinodorus as among the crypt nuts!
Aquarists and gardeners often have a problem with polymorphic species. Many think that every differing cultivated plant could be distinguished by a scientific taxon name. But I think many forms can only be distinguished by suffixes such as numbers, location names, cultivar names etc. Even plants of the same subspecies or variety can vary genetically.

@HeyPK:


> Is Helanthium the genus name for all the grass-like ones with runners?


Yes! E. tenellus, E. bolivianus s.l. (incl. E. angustifolius, E. latifolius, E. quadricostatus (magdalenensis and xinguensis), E. isthmicus, E. australis, E. sp. "Sao Paulo" etc.), E. zombiensis.



> I am also very curious to know if E. uruguayensis has been split up in the new taxonomy. I am a firm believer that it should be. The red and green horemanii plants are a lot different from the narrow-leaved plant that can produce floating leaves.


What we know in the hobby is only a handful of clones that doesn't represent the whole range of variation. In the nature often many intergrading forms occur, connecting our "species", so a taxonomist can't distinguish these "species" among the many natural populations (and among the herbarium sheets). E.g. Christel Kasselmann ("Echinodorus, die beliebtesten Aquarienpflanzen", Dähne Verlag 2001) found many different E. uruguayensis populations in rivers of southern south america - longer, shorter, with broader or narrower leaves, reddish, darker or lighter green...
Samuli Lehtonen (2007) lumps all "species" of this group (also E. horemanii and E. osiris) into a broadly defined species E. uruguayensis. 
We could name them e.g. E. uruguayensis "osiris", E. uruguayensis "horemanii red", "africanus" etc.

@Robert Hudson:


> Is it not a well accepted fact by now that all plant species can vary greatly in size, shape and even color to varying degrees? A while back I got a ton of E. bolivianus from Paul K. and it was quite tall. It grew out in my tanks half the size of the original plants.


Yes, but under similar conditions (in the same tank) the "Tropica-angustifolius" grew shorter and more compact than the "old" angustifolius. So I think they differ genetically - but that doesn't mean they were different species! Surely botanists would consider them only as different clones of E. bolivianus (Helanthium bolivianum).


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## miremonster (Mar 26, 2006)

Hello Robert,


Robert Hudson said:


> They can't even agree on the spelling,


 Don't understand - where do You see differing spelling?


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## HeyPK (Jan 23, 2004)

Here is a picture of the narrow-leaved uruguayensis with the red horemanii uruguayensis in a 75 gallon tank. The former is producing floating leaves with three foot long stems. Has anyone else seen floating leaves from either vareity of uruguayensis?


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## miremonster (Mar 26, 2006)

Hello HeyPK,


HeyPK said:


> Has anyone else seen floating leaves from either vareity of uruguayensis?


 Yes 
4 forms of the uruguayensis group, cultivated outdoor in the botanical garden Goettingen and in an old bathtub in a garden from may to november. The plants root in nutrient-rich loamy soil, in full sun, water level about 20-50 cm.

The forms in particular:
- a broad-leaved, rather light green form from the nursery of J. Hoechstetter (Deisenham, Bavaria), 
this form has during the summer, when it flowers, only long-stalked floating and half-emersed leaves,

- a similar form from northern Argentina, collected by D. Wanke (Germany),

- a rather narrow-leaved form from South Brazil (Rio Peixe), coll. also by D.W., here in the tub last summer:









- a tetraploid form of E. osiris from South Brazil, same collector, in the tub (but waterlevel only about 20 cm):


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## nfrank (Jan 29, 2005)

Heiko,
The Natural history of Echinodorus (Alismataceae)
by Samuli Lehtonen is at the Univ Bibl Johann Christian Senckenberg in Frankfurt

http://www.worldcat.org/oclc/150328087&referer=brief_results

You can take a look!


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## miremonster (Mar 26, 2006)

Hello nfrank, 
thank You - I've got this book, directly from the author 
But I meant, I haven't obtained Lehtonen's newer papers yet.


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## nfrank (Jan 29, 2005)

The PAM article cited at the beginning of this thred has been re-posted at 
http://www.aquatic-gardeners.org/Chainswords-NeilFrank.htm

The original link was temporary and will soon be deleted.
--Neil


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## HeyPK (Jan 23, 2004)

I changed the link in post #1


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## Jane in Upton (Aug 10, 2005)

Cavan Allen said:


> Lastly, what do you make of this? I haven't looked into it much myself.
> http://www3.interscience.wiley.com/journal/119405254/abstract


Well, while the scientific abstract is interesting, I had a bit of a chuckle at this line:

_As a result, two new combinations (Helanthium bolivianum and H. zombiense) are made._

I'm familiar with the idea that oftentimes folks who have the opportunity to name species (and more commonly, cultivars) of plants will incorporate something personal into the name, as a kind of homage. For example, the story of the houseplant Calathea rufibarba, whose name pays a nod to the classifier's wife, Barbara, affectionately called "Barba" by many.

So... this plant Helanthium ZOMBIEnse makes me wonder if it was named by a young researcher, paying homage to....... ???

Tossing ideas from the peanut gallery,
-Jane


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## Cavan Allen (Jul 22, 2004)

Have fun Jane:
http://www.curioustaxonomy.net/

I've read the whole paper. It is quite interesting!


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## Jane in Upton (Aug 10, 2005)

Aw sheesh, Cavan...... its like pointing Alice down the rabbit hole! So much for making dinner tonight, Spaghettios will have to do.

Some of this stuff is just bizarre, while others are hilarious.

This one caused me to snarfle my seltzer:

Rosa 'Whitfield' (rose cultivar) Comedy actress June Whitfield commented, "There is a rose named after me. The catalogue describes it as 'superb for bedding, best up against a wall."​
Proper nomenclature is such a tough thing, battling against entrenched habit, and ubiquitous common names. Its always a hot topic in my (terrestrial) plant clubs. Among the tropical plants Begonia, there was at one point a trend to give cultivars scientific-sounding names, (and these were registered with lower case spelling too, just to throw everyone off!) so there is a whole group of plants which folks keep trying to list as the species they're growing, only to find that no, its a cultivar, but Mrs. Smith, who hybridized it, decided to call it "B. smithii" or some such thing.

I like the way you've cross-referenced the Echinodorus with the now-correct Helanthium, and the synonym listing as well. These changes ARE difficult to integrate into the common usage, but continuing to use what is not correct only makes it more difficult for growers joining the hobby to communicate. We try to use taxonomic names so that we can be sure we're talking about the same thing, but the legacy usage, while easier in the short term, eventually becomes a barrier to communicating effectively.

*stepping down off the soapbox now*
-Jane


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## Jane in Upton (Aug 10, 2005)

And Neil,

What a great article! The pictures of the different types, emersed and submerged, and variants within the species was really helpful!

Among Ariods, particularly philodendrons, its now been found that the SAME species is distributed as many "fixed types". For years they've been given different species names, or the same species, with a variant name. I grow several alongside one another; same potting mix, same conditions, etc, and they look like totally different plants.

Sorry if this veers a bit off-topic, but Steve, of Exotic Rainforest, has a REALLY good and thorough explanation of the fixed variations within a taxonomically identical species here; (crypt folks, this will be right up your alley)

http://www.exoticrainforest.com/Natural variation within aroid and plant species.html

:!: warning - be prepared - there is a birdcall soundtrack, which scared the snot out of me when I first went to that page. 

Great Thread!
-Jane


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## Seattle_Aquarist (Mar 7, 2008)

Hi All,

Erik Olson (The Krib) recently loaned me several copies of PAM which I have been reading and re-reading. It was an excellent magazine.


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