Helanthium tenellum?

[MarcelM]

Hello evrybody..

Recently i got me a pot with Helanthium tenellum, the vendor states it's the South American.. But personaly i'm under the impression he sold me the broadleaf Parvula..

Now do i read at the flow grow database that there should be distinct difference in the flower of the parvula. But unfortunately i can not find any other references what this differnce actualy is. I only have one plant and it's still growing emersed and about to flower.

All i can find on the interent is rather inconclusive, like is still is a Botanicus quarrel about what is what.
Since flowgrow is the only database i could find where the author states there must be clear difference in the flower between both sp. But unfortunately doesn't go any further into what this difference is.

Than my best guess is, one of you dear Flowgrow members probably can lead me to conclusive references to properly ID my plant? Maybe something with pictures?

:tnx:

Schone Grüße Marcel.

 

[Matz]

Hi Marcel ,
I know you understand german language very good, but because you asked in english I'll answer in english.
Please have a look there, may be you'll find answers in that thread: nachricht69009.html?hilit=H.%20tenellum%20parvulum#p69009
Greets, with best regards,
:bier:

 

[MarcelM]

Hello Matz,

yes that's correct, i can understand, read and speak German relatively well, i got it for breakfast most part of my life. My family is German ancestry from both sides. Only writing in German is very time consumming, not to make a compleet fool out of myself. :flirt:

Hertzlichen dank.. :bier:

Marcel..

 

[Heiko Muth (Sumpfheini)]

Hello Marcel,
the green "Broad leaf" H. tenellum is often simply labeled H. tenellum and Echinodorus tenellus, respectively. At least here in Europe, it's meanwhile better available than the one with narrow, reddish submerged leaves.
In the flowgrow plant database and also in the Aquasabi shop, we use the name H. tenellum "parvulum" because the broadleaf one corresponds with the North American H. parvulum, but the latter name is (still) synonymized with H. tenellum in most recent botanical sources.
Samuli Lehtonen has shown with his molecular analyses that "parvulum" actually deserves species status, but there's still no taxonomic treatment where H. parvulum is accepted again. Therefore the info in the web is very inconsistent.

Otherwise the name H. tenellum "parvulum" is hardly used, most nurseries and in-vitro labs name it "Broad Leaf", "Green" or just H. tenellum.

Gruß
Heiko

 

[MarcelM]

Hello Heiko,

Thanks for the vailuable info... Also the earlier posted link to the old parvulum thread was rather very helpfull.

Something dawned on me that i was searching for, for many many years.. I started aquarium in the mid 1970's. And a fellow aquarist gave me a little grassy carpeting plant, it covered my substarte within months in a rather low energy tank. I never new this little plants name. Went out of the hobby for quite some time and came back.. Then i remembered this little plant and went searching on the net.. And i was absolutely unable to find it back, i tried several spp. that resambled it's looks like Sag. subulate but it wasn't that, this grows much taller. Alse the South American HT grows taller what i saw from pics.

Now i red in that old thread, it dawned on me that it must have been the Parvulum i had back then.. The description matches 100%, staying green and not bigger than 5cm submersed. spreading with runners. And it was rather commonly available in the mids of the 20th century. This all adds up perfectly..

What a coincidense to unintentionaly find it back like this.. aket:

Now i realy wonder why this stunning little creeper went out of fashion.
Probably the mix up with several members of it's genus available over time..

Anyway it's this little plant i bought with the label Helantium Tenellum / origin South America.

DSCF1037

• MarcelM
• 23 April 2018

But looking up refences it kinda looked different to me.. I'll make it flower, to see what it shows. It's already half way so it shouldn't be to difficult. If it flowers <10mm in size it should be parvulum if i'm correct. If t's not i definitively will order it at Aquasabi..
:tnx:

Schöne Grüße

Marcel..

 

[Heiko Muth (Sumpfheini)]

Hi Marcel,
I believe your plant is "parvulum", let's wait for open flowers. Red tenellum has narrower emersed leaf blades, longer peduncles, more flowers per inflorescence and smaller flower buds (although the petals are bigger..).
As for the "old" parvulum in past decades, Dr. Helmut Mühlberg (Halle/Saale) told me that the plant was different from the customary parvulum plants that are available today, and that it probably vanished from aquarium culture.

According to Lehtonen, even the "red" Helanthium tenellum turned out to be distinct from H. tenellum that corresponds to the type of the species... that means, Helanthium tenellum in the narrowest sense is probably not cultivated at all :?

Gruß
Heiko

 

[MarcelM]

Hallo Heiko,

It's indeed a rather strange little thing with this little plant.. But in the end i don't mind they sold me a misidentified HT. Reading up on it's North American origine means i can cultivate it outdoors and it might just survive the winter.
Than i will always have enough of it for times to come..

Already did put a small runner in the garden terrace pond tub where it gets full sun all day long, we already have pretty warm weather for this time of year. It might flower sooner than anticipated. Because it took the transplant and cold nights rather well. It's still happy and alive after 4 days.

DSCF1060

• MarcelM
• 24 April 2018

The rest is still in the sump under a 12 hour led, probbaly not bright enough to make it flower. I wait a little longer before placing the complete plant outdoors.

If my assumption is correct and this plant is the same as i had over 30 years ago.. Than it's a real shame it got pushed aside in the hobby. Because i remember it growing like a champion it the worst uncontrolled conditions imaginable. Back in the 70's, CO² was still a myth, red about in magazines for the jet set and professors and completely unaffordable for the working class. Ferts were never heard of, water changes were considered a sin tanks should stink like swamps and tube light development still about in it's infancy. And i had this plant in a 100x50x50cm tall tank on plain sand covering the intire tanks front lawn in a few months time. That's why i was frantically in search for it to find it back, because i never had such a small and easy carpeting plant again. Than in the todays aquascaping hype this can be considered a great loss in the hobby with a big question mark, since everything is about carpeting nowadays..

Planning a new scape anyway somewhere this year and see if i indeed found my long lost love back... Hopes are high.

I let you all know when and if it flowers.. :bier:

Gruß
Marcel..