Ludwigia arcuata or L. brevipes?

[robypellegrini]

Hello to everybody,
I need your help to identify this plant.
I have receveid this specimen labelled as Ludwigia arcuata, but I have some doubts.
Now, in emersed colture, I have observeed the flowers (petals misured about 6 x 3 mm).
I have observed steams and leaf with a normal magnifier but I have not noticed evident hair or small teeth on leaf edge (as suggested in Kasselmann's book).

What do you think?

Have you photos (or links in the web) of a real Ludwigia arcuata hairy steams?

Thank you.

 

[Heiko Muth (Sumpfheini)]

Hello Roberto,

petals 6x3 mm are still in the range of L. brevipes. L. arcuata up to 11x7 mm. (according to Kasselmann 2010)
How long are the pedicels (flower stalks)? L. brevipes to 1,8 cm, L. arcuata to 3,5 cm.
Apparently L. brevipes is often mislabeled as L. arcuata in the trade.

Greetings,
Heiko

 

[robypellegrini]

Thank you for the answer.

Pedicels are about 1 cm.

Now, I must try to find a real Ludwigia arcuata to see the differences

 

[Heiko Muth (Sumpfheini)]

Hi Roberto,
pedicels ca. 1 cm: ok, it's Ludwigia brevipes! Lacking teeth and hairs and the size of the petals are also in line with this species.

Unfortunately I don't have photos of emersed L. arcuata where teeth on the leaves or hairs on the stem are visible.

Greetings,
Heiko

 

[robypellegrini]

Hi to everybody.
Incredible :shock:
The plants that I bought as "Ludwigia brevipes" have flourished.

This look like a typical Ludwigia arcuata flower: diameter 2 cm, petals 0,9-1 cm x 0,5-0,6 cm, pedicels 1,6 cm.

In this photo you can see the two flowers compared: on the right this "Ludwigia brevipes" (probably a really Ludwigia arcuata), on the left the ex "Ludwigia arcuata"(probably a really Ludwigia brevipes) showed above.

There is much confusion among the commercial suppliers... :roll:
What do you think?

Directly observed, flower of Ludwigia arcuata are really the largest of all opposite leaf Ludwigia diffused in our aquariums.