I thought it could be some kind of big Schlumbergera sp.,
I googled all the species native but didn't get a match. The leaves are much bigger than a regular Schlumbergera too.
http://floradobrasil.jbrj.gov....

I often found them in the wild as well as in gardens growing epiphytic on tree trunks..
These picture are taken in a friend's garden in Paraty.

Some info..

http://www.cssainc.org/index.p...

Schlumbergera orssichiana .. leaf edges too jagged.

http://cactusepiphytes.pagespe...

http://www.google.co.uk/search...

schlumbergera kautskyi .. not a match

http://schlumbergera.net/speci...

Schlumbergera opuntioides .. definitely not a match!

http://schlumbergera.net/speci...

Schlumbergera russelliana .. doubt it.

http://schlumbergera.net/speci...

Schlumbergera truncata .. jagged edges.

http://schlumbergera.net/speci...

Schlumbergera microsphaerica .. jagged edges.

Look at other genera.. Hattiora .. none match.

http://hatiora.net/

Epiphyllum .. possible!

http://www.f-lohmueller.de/cac...

I've looked at examples of about all the other genera in Cactaceae and can't find anything else so it's probably an Epiphyllum hybrid.

http://floradobrasil.jbrj.gov....

http://www.google.co.uk/search...

Thank you Janet! I think I have found it! it is Epiphyllum oxypetalum.
The flower is gorgeous but it was not blooming the time I was there unfortunately. It is night-blooming and is called 'Dama da Noite'= 'Lady of the Night'.

My half-Brazilian friend has given me its popular name, should have asked her before! There are more plants called that way but she recognized it by the flower.
http://search.babylon.com/imag...

I checked Epiphyllum oxypetalum Myriam, there's very few Epiphyllum native to Brazil, only two species and a subspecies and none of those match. That one has long leaves without the joints.. how I wish I could grow it!

http://mykmanon.com/Flower_Pag...

http://www.google.co.uk/search...

True! I jumped too fast to conclusion! The leaves don't match indeed!
I'm not sure if it would be a hybrid Epiphyllum, because I saw identical ones very often in the wild, or maybe a natural hybrid then? The ones I photographed in the garden were not planted but appeared spontaneously like most of the plants in that garden.

It could be a natural hybrid, or one which has escaped civilisation! Fancy that, not only can you grow such plants with ease there, they are free!

They even invite themselves!

That is definitely an epiphyllum. It's unmistakable in every way.

Had a friend of mine looking around ATP and when he saw this thread he told me he was sure it was a Rhipsalis crispata. May want to check that out and see what you think.

Reminds me of Rhipsalis elliptica

oops ... I see JB mentioned Rhipsalis crispata

http://garden.org/apps/sets/vi...

http://rhipsalis.com/species/c...

It looks more like R. crispata then R. elliptica, don't you think, Lin? I have R. elliptica but not familiar with the other one.

Tee, it does look more like R. crispata. I used to have elliptica so I that's the one I thought of when I first saw Myriam's photos.

Rhipsalis does look a good bet, there are several species in the area around Rio de Janeiro. R. pachyptera is one of them, I have checked out all the species and there is more than one which could fit this plant, Rhipsalis crispata is also present.

https://sites.google.com/site/...

Rhipsalis crispata looks to have too many lobes ..

http://reflora.jbrj.gov.br/jab...

I'm still leaning towards Rhipsalis but don't know which it might be. For comparison, more images:

R. crispata: http://rhipsalis.com/species/c...

R. pachyptera: http://rhipsalis.com/species/p...

I wouldn't even try to guess a species Lin, there are others which look very similar. The site I linked to for R. pachyptera shows photos in location in Brazil.

I'm glad this old thread got bumped up Jacquie! Thank you all for your input!

I've looked at both Rhipsalis crispata and elliptica of which crispata looks closer indeed, but still not a match.

Wow Janet you have checked out all 24 species occurring in the region!
I googled Rhipsalis pachyptera and this is the best candidate for now. I still have to check the others..

Maybe the new photos I took of what I think are of the same plant will shed a better light, especially because some show the fruiting bodies, these were all taken in the wild.

The last two photos of fruiting bodies as well as the leaf shape do match Rhipsalis pachyptera well Myriam! There's more than one species in the illustration, look at #6.

http://www.plantillustrations....

I don't think the first two of your last set are the same though.

The above site has drawings of many species, it may or may not help.

http://www.plantillustrations....

R. pachyptera does look like a match: http://rhipsalis.com/species/p...

No info or photo's in the ATP database yet. Parrot's Beak (Rhipsalis pachyptera)

Yes, it does.