I wanted to take more and better details of this plant, but then my attention got drawn away by a snake gliding on the rock above my head, who was curious what I was doing.

The main stem of the climber had more rounded leaves, (full of rock dust on the pics), than the side shoots with more elongated leaves.

This is very similar to Marcgravia umbellata which is a little to the west of the coast .. family Marcgraviaceae. There's very few if you select Rio de Janeiro and Atlantic Rainforest, but a lot of entries otherwise.

http://www.araflora.fr/p1639/m...

I've selected only the south-east.

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

This is the site I found Marcgravia ..

http://flickrhivemind.net/Tags...

Marcgravia polyantha is in the area, the leaves vary but look more pointed.

https://www.flickr.com/photos/...

They differ on Flora SBS

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

Definitely a Marcgravia Janet!
There are only two species of it in the Rio de Janeiro state:
http://floradobrasil.jbrj.gov....
Marcgravia polyantha and Marcgravia comosa.
Unfortunately I cannot find photo material of the last one on the web..
I does look very similar to Marcgravia polyantha, and it appears to be a bit variable in leaf shape.. but it looks like the mid-veines on mine on the side shoots have a whitish colour, but maybe that is just due to the light angle that falls on it..

I was just looking again at your first link and Marcgravia umbellata has that whitish mid vein!
But it is not supposed to be in that area..
http://www.araflora.fr/p1639/m...

They do vary according to age Myriam, the growing conditions might make a difference too.

There's more photos showing the rounded leaves on Marcgravia polyantha which have a paler edge. It's amazing how they change from growing on a tree trunk to a shrub, they are 'hemiepiphytes'.

http://www.ufrgs.br/fitoecolog...

Marcgravia polyantha is listed on the following link which I started to go through but didn't get that far ..

http://www.scielo.br/scielo.ph...

Just saw your post, Marcgravia umbellata does look a better fit! It's not far away so could be the one.

Yes, I think so too, it is listed in the Flora do Brazil for Minas Gerais which is actually close by, I've been there too some years ago..
http://floradobrasil.jbrj.gov....
I don't think plants care about human-made divisions between neighbouring states..
I consider this one as solved!
Thank you so much!!
And you found it so quickly!

Just found out that Marcgravia umbellata is now synonym for Marcgravia rectiflora!
http://www.catalogueoflife.org...

It is confusing..
Some of the photos on the web look a very different plant from mine..
Shingle Vine (Marcgravia rectiflora)

This one looks more like it though, but missing the pronounced mid-vein:
http://floraelverde.catec.upr....

maybe mine was a young plant,
I see in this photo that the side shoot leaves have the same shape as mine..
https://www.google.be/search?q...

The Plant List gives Marcgravia umbellata as accepted, there's no notes to say the name has been changed.

http://www.theplantlist.org/tp...

http://www.ipni.org/ipni/plant...

This type of plant starts it's growth from seed transported to a tree (by bats or other life forms), when it reaches the ground it then takes root and a different form.

https://en.wikipedia.org/wiki/...

Marcgravia rectiflora is also accepted.

http://www.theplantlist.org/tp...

Barker: (A) standardisation made on 2012-02-27 14:48:42.0
• nol: (A) made on 2016-01-30 08:15:45.0

http://www.ipni.org/ipni/idPla...

It is true Janet that when I google Marcgravia umbellata i find much more matches than under Marcgravia rectiflora, they do look different plants despite the leaf variation.
Marcgravia rectiflora is not listed in the Flora do Brasil for the entire country.
But the fact is that our database will not accept it as they take the Catalogue of Life as the authority..

?
@zuzu
@eclayne

Yes Myriam, I mentioned Marcgravia rectiflora wasn't listed but the seeds could have been transported by a bat or bird, some Marcgravia are pollenated by bats.

Both species are accepted on the Catalogue of Life, putting the link to the other thread here:

http://garden.org/thread/view_...

Thanks Janet, my mistake!

I've added Shingling Vine (Marcgravia umbellata) Thanks for all the research Janet and Myriam.

FYI, In case you run across images with that author, the COL lists Marcgravia umbellata Griseb. as a synonym for M. rectiflora.
http://www.catalogueoflife.org...

Thanks Evan!

What about the snake? Any photos?

I won't disappoint you Leslieray
it was a thin snake but quite long, it could be a juvenile. I've seen much bigger and fatter in another spot, one dropping herself down from a big rockwall on a huge flat bolder by the river, landing only a few meters from where I was standing, she was very curious too, and came sliding towards me, somehow I felt she wasn't dangerous for humans, just curious and that was mutual!
Afterwards I found out it was a Tiger Ratsnake (Spilotes pullatus) living from rodents.
I even made a video film from it.
This was a little one, about 1m long: