Identification needed!

[Secundino]

There is an unknown Acanthaceae growing in two baskets with orchids and I have not been able to identify it. As far as I am aware it is not part of local flora, and I assume I got it through bark substrate.
Does someone know a good place for identifying little weeds? May be a forum or another site.
Thanks!

 

[NYEric]

a photo would go a long way..

 

[Secundino]

Yep, I've a lot ... I just need a site to place them! :wink:

But for you, I'll upload one here, too:

These are the capsules (the strongest evidence that it is a Acanthaceae, I'll be sure when it opens) and the 'flowers': I've never seen them open, or larger or anything else then these white (presumably four petals same as the calyx) hoods, tomorrow there will be two more capsules, already big. The leaves - simple, with cystoliths - are opposite, decussate, shiny and scarcely hairy, only three to four pairs of them; the whole plant is just around 10 cm in height.

 

[Secundino]

No one has an idea where I could get this plant identified?

 

[SlipperFan]

No one has an idea where I could get this plant identified?

Do you have a university nearby with a biology or a botany department?

 

[gonewild]

If it was from tropical America you could try the Facebook group FacePlant.
A lot of knowledgeable botanists there. Maybe someone on there also knows plants from other parts of the World so give it a try anyway.

 

[Secundino]

No estoy en caralibro, nor do I intend to join facebook.

Yes, there is a University nearby, though the main botany department is on Tenerifa Island. I'd have to pot the plant and take it there... but perhaps I'll just sow a few seeds (if I get them before the capsule explodes...) and go there in a few weeks.
Thank you for these ideas; if I ever get a clue what it might be, I'll post.:wink:

 

[Secundino]

After the first spike did not produce any open flower but three pairs of capsules, the second spike DOES flower!

The flowers are fairly big and showy for the little plant, not ephemerous at all. Searching through the net, I wonder if this plant can be an Australian native Acanthaceae, considered a weed by Australian orchidist: Pseuderanthemum variabile? This plant is said to not produce flowers at times and having a rhizome (which I haven't seen up to now). Though one thing does not fit, and that is the type of inflorescence ...
I'd appreciate to have some response from our Australian growers!

And how did this plant arrive at the antipodes ...?? (orchiata...?)

 

[PaphMadMan]

It looks like you have your identification. This species is found in parts of the southeastern US now, so I wouldn't be surprised to find it as an introduced weed almost anywhere. In what way is the inflorescence not as expected? If a plant is stunted or stressed, when I assume it would be most likely to show cleistogamy, I wouldn't be surprised to see it also produced abbreviated inflorescence morphology that might seem atypical.

 

[Lanmark]

It certainly has pretty flowers!

 

[Ozpaph]

Could you show a less magnified view of the plant? Does it have a tap root?

 

[SlipperFan]

It is a weed! Grows rampant in greenhouses. Worse than oxalis. It has a very long tenacious root. It throws seed all over, and once it is established, it is very difficult to eradicate. But it is pretty.

 

[Scott Ware]

Everything Dot said x10. This weed has the tap root from hell.

 

[Secundino]

... then I should eradicate it as long as it only grows in two baskets. But the seed capsules have already exploded and completely disappeared...!

Thanks to you all!

 

[Ozpaph]

Then it is the horrid weed that we have here. The only way to eliminate it is repot and destroy the old mix. Poison any growing under the benches.