# Limnophila aromatica vs Pogostemon stellatus broadleaf



## hoppycalif

How can you distinquish between








and









I have what was identified as L. aromatica when I purchased it here on the forum many months ago. It looks like the photo above - both of them. My tank grew wild over the past 3 weeks, and some of the plants are showing emersed leaves above the tank now. Those don't look like the emersed leaves shown in the Plantfinder picture. They, like the submersed leaves are in a circle of 5 leaves around the stem, followed by about a half inch of stem, and another circle of 5 leaves, etc. When I crush the stem or the leaves I don't detect much of an aroma. So, can this be L. aromatica?

Are there other plants that look almost exactly like L. aromatica? I would take photos of what is in my tank, but it is in too bad a shape to allow that.


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## BryceM

I've been fooled by these two myself. P. stellatus 'Broad Leaf' will have purple internodes and L. aromatica will not. Now that I have both species in the same tank, I can tell you that L. aromatica can be highly variable in its appearence. P. stellatus 'Broad Leaf' tends to be a a much larger plant, with woody stem diameters of over 1 cm and entire plant diameters of almost 6 inches when growing well. L. aromatica tends to be smaller with more branching.


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## hoppycalif

This photo from the Plant finder shows green internodes, and about 5 leaf groups of leaves between internodes.










But this photo from the same place, for emersed leaves shows 3 leaf groups between internodes:









My internodes are reddish purple, and the emersed leaves, which may still be in submersed form, for all I know, are in 5 leaf groups.

The largest stem diameters I have are closer to .5 cm than 1 cm, and aren't woody, but they are, as I recall, hollow.


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## houseofcards

Just a little history,

The plant in question, which I think is the one you got from me was purchased from Aqua Botanic in late '05 as Eusteralis stellata wide leaf. When I showed my tank here at APC some of the senior members/mods identified the plant as L. aromatica. This prompted me to create a thread asking others what they thought it was. That thread can be seen here:

http://www.aquaticplantcentral.com/forumapc/aqua-botanic/12489-e-stellata-wide-leaf.html

It was determined by the vast majority of members to be L. Aromatica. Once it acclimated itself, the plant grew widely for me for about a year. Literally busting my tank at the seams. Although I still have the plant it has a stop and go growth that I have still not fiqured out and I believe it to be the most psycotic plant I have ever had.


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## BryceM

Hmmmm. Stop and start growth is more typical of Pogostemon IME.

The switchover to emersed growth doesn't happen all at once. The leaf morphology can be fairly unusual until a stable growth pattern emerges.

Pogostemon stems seem to have a more hollow appearance, at least when they get large.


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## hoppycalif

houseofcards said:


> Just a little history,
> 
> The plant in question, which I think is the one you got from me was purchased from Aqua Botanic in late '05 as Eusteralis stellata wide leaf. When I showed my tank here at APC some of the senior members/mods identified the plant as L. aromatica. This prompted me to create a thread asking others what they thought it was.
> 
> It was determined by the vast majority of members to be L. Aromatica. Once it acclimated itself, the plant grew widely for me for about a year. Literally busting my tank at the seams. Although I still have the plant it has a stop and go growth that I have still not fiqured out and I believe it to be the most psycotic plant I have ever had.


Yes, now I recall that you are the source of my L. aromatica. And, it remains an absolutely beautiful plant that grows very well, very consistently for me. It has been without fertilizing for three weeks now, and the new growth is almost white, but it continues to grow vigorously.

I am ready to give up on high light intensity, and have raised my light fixture 6 inches to drop the intensity to low to moderate. So, I am planning to dispose of my high light plants, which consist of L. aromatica, H. porto velho and Lobelia cardinalis small form. I want to be reasonably sure of the identification before I turn the L. aromatica over to others. I began to doubt the identification when Tom Barr passed around a stem of his, and I noted that mine doesn't smell at all like his. I mentioned that mine has hollow stems when they get big, and Tom say's nope, not L. aromatica. I had no idea that identification would be so difficult. I expected that Cavan would take one look and say exactly what it is and why.


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## AaronT

It's not uncommon for the emersed form of a plant to have a different number of leaves per whorl than the submersed form. A perfect example of this is _Ludwigia inclinata_ var. _verticillata._

As Bryce mentioned the easiest way to tell is to look at the base of the leaves as they come off of the stem. If it is a _Pogostemon_ it will have a purple "ring" around the stem.


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## HeyPK

Just to illustrate Aaron's point, here is a picture of L. inclinata var. cuba switching from emersed to submersed growth.


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## AaronT

That's a great example. Thanks for posting that pic.


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## hoppycalif

AaronT said:


> It's not uncommon for the emersed form of a plant to have a different number of leaves per whorl than the submersed form. A perfect example of this is _Ludwigia inclinata_ var. _verticillata._
> 
> As Bryce mentioned the easiest way to tell is to look at the base of the leaves as they come off of the stem. If it is a _Pogostemon_ it will have a purple "ring" around the stem.


OK, I looked carefully, and there is no purple ring at the internodes. Instead, the "ring" is green, even though the rest of the stem is reddish purple. So, I do have L. aromatica! Thank you all very much.

Now, why doesn't it have a distinct smell when I crush a stem or leaves? Or is that smell more subtle than I was lead to believe? I can barely detect a difference in smell from any other plant.


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## AaronT

hoppycalif said:


> OK, I looked carefully, and there is no purple ring at the internodes. Instead, the "ring" is green, even though the rest of the stem is reddish purple. So, I do have L. aromatica! Thank you all very much.
> 
> Now, why doesn't it have a distinct smell when I crush a stem or leaves? Or is that smell more subtle than I was lead to believe? I can barely detect a difference in smell from any other plant.


The smell is pretty strong. Is there any way you can take a picture of a stem of it?


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## Bert H

Is the smell only on the emersed growth, or will you also get it in submerged?


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## AaronT

The smell is there in either form.


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## houseofcards

This plant is the source:


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## hoppycalif

houseofcards said:


> This plant is the source:


Ah, the mother plant! Mine look just like this one, except that those really close to the light have reddish purple stems between the nodes, and those farther from the light are now very pale green/yellow, almost white. I can't get photos of mine due to the algae farm I now have. Does the mother plant have the typical strong smell??


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## AaronT

That is most definitely Limnophila aromatica.


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## BryceM

I agree. That photo is definately not P. stellatus 'Broad Leaf'.

I gotta admit though, these two plants are easily, easily confused. My L. aromatica has a very distinctive smell, but you have to crush up the stems to really smell it.


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