[pweifan]

While vacationing in the Orlando area, I was able to do some local plant collecting. This plant was groing in very sandy soil about 9-12 inches below the surface of the water. It sure looks a lot like Hemianthus Micranthemoides to me. Can one of you experts confirm?

 

[Axelrodi202]

Doesn't look quite like HM. Might be a Bacopa species of some sort.

 

[pweifan]

Interesting. It was growing near the bacopa below. Do you think it might be the same plant?

 

[Axelrodi202]

I'm not an expert or anything, but it could be. Try crushing one of the leaves. Is there a herby smell? Some Bacopa species have that.

 

[pweifan]

The two plants smell a bit different. Maybe due to submerged vs emergent growth? I guess I'll just have to plant them and see

 

[Tinanti]

No, not Hemianthus micranthemoides, which is/was a plant of tidal areas in the Northeast, not Florida. As of next month, it will not have been seen for 70 years. Nobody is growing the real thing. In Florida grows H. glomeratus, which is very similar and common in the hobby. Everybody is really keeping that. Differences explained here (with pics!):
http://www.aquaticplantcentral.com/forumapc/plant-id/77299-hemianthus-glomeratus.html

Your plant is neither (too stiff, and with opposite, not whorled leaves). It does look somewhat like Lindernia grandiflora (the stem on the right, more so), but it's hard to say from the photo. Could be Bacopa monnieri or a stem of both, but again, the photo...

 

[Axelrodi202]

In the northeast you say? I think I know what plant I'll look for next time my family goes boating...

So basically what's being called HM in the planted tank hobby is either H. glomeratus or a similar species? Interesting. What about the variant of the plant with two leaves per node? I remember reading somewhere that that was a Japanese variant or something along those lines.

 

[Tinanti]

It's H. glomeratus, yes, which is endemic to Florida. I collected some last year, and guess what it looks like...

H. micranthemoides is from tidal flats of tidal rivers above the reach of salt water. Tributaries and streams feeding those larger rivers are the best places to look. You can see some distribution on the USDA site, but it's a bit out of date as far as extant or not, etc.

The two-leaved plant is similar and possibly the same as an apparently unidentified species from the Caribbean. It may have been popularized in Japan, but that's all (not from there).

 

[pweifan]

Tinanti, I'll take better pictures and post them tomorrow.

I remember seeing a discussion that what we think is HM isn't actually HM. Thank you for clarifying.

 

[pweifan]

Tinanti, here are more pictures of the plant in my tank. Please forgive my horrible photography skills. Some of the leaves look rather like bacopa. It's fascinating to me how the same plant can take on such strikingly different characteristics.

 

[Tinanti]

I don't quite know what to tell you. Not a Hemianthus I think. I'd just try to take care of it and grow it out a bit. The answer may come later. If you can, grow some outside for the summer.