I've tried searching online for similar looking plants, the closest one is a Begonia pulchella. But as I've never seen B. pulchella in person before, I can't be sure, also the images showed a much deeper green color than the color of the plant in my post above. Any ideas? Thanks.

It does look similar, just a bit different at the leaf margin. The one in my pictures seems to have smooth margin, rather than serrated like in some descriptions of P. begoniifolium I've found.

Hmmm.... Could you tell us where you photographed the plant(s)?

I'm getting more and more curious.. :D

The plants are in Mount Tidar (more like a hill, really, about 503 meters above sea level), in Central Java, Indonesia.

Alrighty.... Now we're cooking with fire ;)

Compare with the native East Indian Klugia (Rhynchoglossum notonianum) ... I think it's a fit, but you saw your photographed plants in person, so you'd be a better judge.

Ooohh, fizgig777, I think you nailed the genus! Further googling shows a close match with Rhynchoglossum obliquum.

The one thing that's bugging me now is wishing I could go back there to see it flower (absolutely no idea when, not to mention 12+ hours drive from where I live and the hike...), just so to be 100% sure, hahaa.. ;D

Yeah, well.... The driving & hiking is all on YOU =P~~~~

Glad you finally have an ID... Most of the few plants in that genus look so similar that it would take a look at the flowers to tell them apart, IMO. That's nothing new in the tropics, though ;) I'd take the genus and be happy enough with that for an ID until I ran across the plant(s) again in bloom ;) Given WHERE you found the plant, I'd still lean toward R. Notonianum, but without flowers a lean is all I've got.

Well, that was a fun treasure hunt -- so-to-speak ;)