There's other Luetzelburgia species which show similar flower buds, I only found a preserved specimen of the leaves of Luetzelburgia trialata which looks to match ..
http://fm2.fmnh.org/plantguide...
http://www.europeana.eu/portal...
Luetzelburgia trialata is the only species given for the Atlantic Rainforest. I haven't gone through the whole list of Fabiaceae for the area but did up to this species.
