Water Plaintain

Slightly boring prelude: While visiting a nearby park fishing pond, I found a new plant that I had never seen there in past years before. Those flying Canadian visitors are always bringing some interesting stuff in ! After discovering several individuals of the species in the brownleaf and sago pondweeds (and the ubiquitous "bushes" of Elodea), I figured I would take the interesting plant home with me. I grabbed the second healthiest one, and after searching around a bit, I have decided that it is probably a Water Plaintain (there isn't any frogbit up here, is there?)



I snipped off the stems that broke from my sister's rough handling. It's been sitting with its roots in a water filled bucket for about two days now, with the leaves emersed. Anyways, according to Wikipedia, if Alisma spp. is placed underwater, it will grow long "submersed form" leaves. Since Wikipedia isn't always right, I was wondering if this is indeed the case. Would snipping off the emersed leaves speed up the conversion (like it did when I first got some cardinal plant?) Most importantly, if I put this plant in my aquarium, does anyone think it will survive?
Thank you for your time!

Are other plants able to grow under the bulbs that you have? If so, I don't see any reason why this plant wouldn't. Other people have grown them in their aquarium before. Link: http://www.aquaticpl...C&cutoffdate=-1

I did find that thread while looking for more information on the plant, but it doesn't provide a whole lot of information. I also don't know if that user actually was able to keep that plant for a good length of time or not.
I think the lighting is good, two 15 watt 6700 kelvin compact flourescents plus the light from a south facing window have grown most of the things I've put in the aquarium to date, (with one strange exception: duckweed). There is also a thick layer of soil under the gravel. The reason I'm hesitant about the Alisma is because, of the plants I've put in there before (elodea, two pondweeds, some sort of spike rush, marsh marigold, cardinal flower, hornwort, cabomba, ludwigia, bladderwort, and some sort of knotweed), they were either bought from an aquarium store or collected growing underwater, not emersed like the Water Plaintain is. Also, the plant is just so big that it'd be a shame to have it be in the center of the little aquarium, rotting away. I hoped that maybe someone on here had kept it and was able to offer some advice. But I suppose I'll eventually put it in there anyways... ...you've given me a little more courage to do so!

It looks like Alisma subcordatum, but the leaf bases do look rather cordate for that species. Perhaps it's just the angle of the photo. Any way, I don't think that species grows submerged. I've never seen it that way; only in areas where such flooding wouldn't really be a permanent risk. You could always try it, though. Just be prepared to lose it if it doesn't work out.

Edit: I have most often seen this plant with the base of the plant and petioles underwater. But the leaves are emersed.

It looks like Alisma subcordatum, but the leaf bases do look rather cordate for that species. Perhaps it's just the angle of the photo.

Do these pictures help clarify any?







I apologize for inquiring, but you've got me interested now.

If they usually don't grow underwater, then I'll just plant it in a little dip in the backyard that is always a puddle. The flowers look nice in a dainty way.

By "leaf bases" I mean where the blade joined the petiole (not where the petiole joined the basal rosette). Anyway, your last photo has a different angle and the blades look much less cordate and more like what I am used to seeing.

I do think the "dip" in your backyard would be a good spot. Or in a pot that doesn't have a drain so that you can keep the bottom part underwater but the leaf blades above water. The flowers are rather neat. I've always liked the stuff that you have to get up close to in order to appreciate.

Oof, I'm sorry. Shows how much I know!
Sounds like the puddle is the way to go. Thank you for your time and help!

(with one strange exception: duckweed).

Duckweed is highly sensitive to growth inhibiting chemicals emitted by other plants. http://www.apms.org/...ol27/v27p90.pdf

How interesting! It's probably true, since I tried adding the duckweed only recently, with my tank absolutely packed with growth.
The more you know...

Edited by Orangespotted, 17 September 2011 - 09:21 PM.

Duckweed also seems to be a little light sensitive. You rarely see it growing in open sun. I think a light that close can burn it.

I'm not sure that's A. subcordatum either- it looks different from how it grows here. If I found it down here I would try to key it out as a Sagittaria first. I believe there are some other Alisma species up your way, though.

I planted a small A subcordatum in 12" deep water under low light. The plant did nothing much for a long time, then sent up floating leaves with long flimsy petioles. The leaf blades were pretty much the same shape as the "normal" form, but were a bit on the small side. I don't think I have any pictures of it.

In NC I see Alisma with emergent or floating leaves, never submersed (except new leaves on the way up).
Post some flat pics of the leaves showing the vein pattern -- that'll help distinguish Alisma vs Sagittaria or Echinodorus.
Also if you can find one blooming or even an old dead flower stalk, that would help.

In NC I see Alisma with emergent or floating leaves, never submersed (except new leaves on the way up).
Post some flat pics of the leaves showing the vein pattern -- that'll help distinguish Alisma vs Sagittaria or Echinodorus.
Also if you can find one blooming or even an old dead flower stalk, that would help.

I went back to the pond for further investigation. Unfortunately, the only thing blooming there right now are the daisy fleabanes and marsh marigolds. However, I can definitely provide a picture of the leaves and their veining.





I was under the impression that most Sagittarius species usually had tuberous roots, which is why I ruled them out while trying to figure it out myself. By Echinodorus, do you mean the species that some fish stores sell as sword plants?

I planted a small A subcordatum in 12" deep water under low light. The plant did nothing much for a long time, then sent up floating leaves with long flimsy petioles. The leaf blades were pretty much the same shape as the "normal" form, but were a bit on the small side. I don't think I have any pictures of it.

Interesting account. I just planted it outside in the puddle last night, but if it ever reproduces on its own I might try putting the offspring in an aquarium and see how they do. That way there won't be such a large (for a 10 gallon aquarium...) plant sitting in the center of the tank, decomposing.

All of the Alismataceae in our area (including Alisma, Echinodorus, and Sagittaria) can have rhizomes or tubers. The roots of Sagittaria are septate (divided by cross-walls, showing up as rings on the roots). I can't see that in your close-up pictures, but I couldn't swear it isn't there. Your flat leaf shots do look more Alisma-like to me. Something about the whole-plant shots seemed out of place, but I can't put my finger on it.

Echinodorus does include the aquarium sword plants. There are some native species (usually called "burheads" in plant books). The larger burheads are similar to Alisma in appearance and habitat preference. The inflorescence is more like Sagittaria though.



Gerald- I didn't know there was a venation difference. After looking at some specimens, the only thing I can see is that in Sagittaria and Echinodorus the major veins all radiate out from the petiole attachment, while in Alisma the three centermost veins run together a little past the petiole attachment (as in Orangespotted's photos). Is this what I should be looking for?

Gerald- I didn't know there was a venation difference. After looking at some specimens, the only thing I can see is that in Sagittaria and Echinodorus the major veins all radiate out from the petiole attachment, while in Alisma the three centermost veins run together a little past the petiole attachment (as in Orangespotted's photos). Is this what I should be looking for?

Some of the Sagittaria can have veins radiating from further up the midrib, but these are mostly the sagitate leaf forms. Another useful characteristic is that the Alisma petiole appears to extend into the blade as a thick midrib, whereas in Sagittaria, the petole has a more abrupt stop before the midrib begins.

I'm still thinking Alisma, but now also thinking that it could be an oddly subcordate form of A. triviale. There is a bit of back-and-forth as to the phylogeny of A. triviale, A. subcortadum, and A. plantago-aquatica, but Crow & Hellquist cite genetic studies that seem to indicate they are distinct species. In either case, there is a lot of plasticity in the species of this genus (as is also the case for Sagittaria).

Thanks for the info!

I'm starting an Alismataceae-centric water garden, so hopefully I will become better at ID'ing these things as I go along.

All of the Alismataceae in our area (including Alisma, Echinodorus, and Sagittaria) can have rhizomes or tubers.

Water plantains and duck potatoes! I'm going to pretend that I knew that all along...

Something about the whole-plant shots seemed out of place, but I can't put my finger on it.

Well, the plant had a slightly fuller and bigger "shape" to it at first. On the collection outing, I brought along my little sister, who wanted to help out. It was nice that she was excited about it, but little kids aren't very gentle with living things... about 5 or 6 leaves were banged up or snapped on the outside of the plant. The curved shape of the outer petioles (I hope I got that right) that made the plant kind of bowl-like in appearance was lost when my pruning instinct got the better of me (you can sort of tell where I snapped them off in the close up pictures of the base). That may be why it looks a tad odd.

I'm still thinking Alisma, but now also thinking that it could be an oddly subcordate form of A. triviale. There is a bit of back-and-forth as to the phylogeny of A. triviale, A. subcortadum, and A. plantago-aquatica, but Crow & Hellquist cite genetic studies that seem to indicate they are distinct species. In either case, there is a lot of plasticity in the species of this genus (as is also the case for Sagittaria).

When I first typed up this topic looking for help, I was just hoping to know if I had guessed within the correct genus! It is absolutely fantastic that you are able to narrow it down to a species or two, especially considering how difficult it is to identify (well, even to prove the unique existence of) plant species with their enormous rate of variability compared to the vertebrates I'm more familiar with. Almost every time I'm outside, I wish I knew someone who could tell me what each and every pretty little "weed" is. My only self guides to these things are Google *cringe*, the USDA plants database (actually pretty good), a little book that I got in kindergarten because the library was giving away outdated books ("A Golden Guide: Flowers" by Herbert Zim and Alexander Martin, published in 1950...), and another book I got a few years ago that was also given away ("A Golden Guide: Pond Life" by George Reid, 1987). I sincerely appreciate your help!

@Newt

It seems to grow fast… It has already thrown up two more leaves and there is another one is on the way since those pictures (I later cut off that brown stalk because it appeared to be decaying).

Phew, what a long post... I hope I didn't bore anyone to death!

Thanks Laura. I just knew they "looked different" and could distinguish them looking at the basal veins, but I'd never tried to describe the difference, so I'm glad you did! Yes that plant IS Alsima. I've only seen A. subcordatum, the only Alisma in the Carolinas. I see that A. gramineum, a more northern and western species, showed up ~10 yrs ago in eastern VA.

PS - Keep in mind there is also a TRUE plantain species that is aquatic, Plantago cordata, that might be confused with Alisma or Echinodrus at first glance. The "water plantains" are not even distantly related -- Alisma is a monocot, Plantago is a dicot.

Some of the Sagittaria can have veins radiating from further up the midrib, but these are mostly the sagitate leaf forms. Another useful characteristic is that the Alisma petiole appears to extend into the blade as a thick midrib, whereas in Sagittaria, the petole has a more abrupt stop before the midrib begins.

I'm still thinking Alisma, but now also thinking that it could be an oddly subcordate form of A. triviale. There is a bit of back-and-forth as to the phylogeny of A. triviale, A. subcortadum, and A. plantago-aquatica, but Crow & Hellquist cite genetic studies that seem to indicate they are distinct species. In either case, there is a lot of plasticity in the species of this genus (as is also the case for Sagittaria).

Edited by gerald, 22 September 2011 - 11:36 AM.

Here's what I believe to be a water plantain that I have had in my tank for just a little over 2 months now.The narrow leaves are the ones that have grown submerged. I have only had one leaf melt since I put it in my tank. But it was in bad shape before hand.

My bet is that the new growth bolts to the surface. If you find a way to trick it into growing new submerged leaves, that'll be cool and let us know how you (it) did it. Not sure what if anything is under your sand, but if new growth is weak then you might want to pot it in some nice rich mud, and bury the pot under the sand.