Just to make your lives a little harder, this is a partial leaf from a juvenile plant. Genus and species, please.
Wow, no takers? Here's a clue, then. The plant has inflorescences with minute florets, rather than conspicuous, traditional flowers.
I realize we aren't playing Twenty Questions, and I really doubt I have the breadth of experience to come close. However, I looked for things that might be telling. We are only looking at one leaf. I'm assuming it's not a cotyledon, but I suppose some could be that complex and that large. And large is relative. Going by the grass like blades nearby, it's pretty darn big. The venation might be an identifying characteristic. It's pretty definite. The speckles of anthocyanin on the petiole could be more pronounced on an adult plant. I don't see it on the leaf and it doesn't appear to be on the underside, but that's just a guess looking at only the top of the leaf. The fact that it's erect may be misleading. The other flora and the terrain are hard to make out. I could put granite outcroppings as the fuzzy white background, but it could be sand or concrete or ostrich droppings... So no help with that. The smaller leaved plant behind has red stems, opposite, ovate leaves. The "grass" could be a sedge judging by the apparent stiffness. I'm thinking the terrain is wet and rocky, possibly adjacent to a stream bed, and that this plant is a fast growing wild annual plant that will grow in a cooler climate. I suspect the leaves may form a rosette, but I have no idea why I'd think that. The venation alone makes me think of emersed aquatics, but it doesn't look like any I've known.
Ok, thanrose, you're almost on the right track except for your extrapolations about location and climate. This is a dry ground perennial in the Upper Amazon Basin, and I've never seen this plant, wild or cultivated, outside of this climate zone. I expect it would tolerate a bit cooler, but nothing lower than nighttime temps of about 16 C. It's definitely not a riparian. You're bang on that we're looking at one leaf which is not the cotleydon, though. Ditto your observation about the anthrocyanin on the petiole, but only in about 50% of adult plants, for no reason that's immediately obvious to me. It is an erect plant when it reaches maturity, and the only real difference between the juvenile leaf shown and the adult ones is size - adult leaves can be up to 30cm across the widest points. The leaf pictured is about 10 cm across. The venation is a defining charecteristic for this plant. So is the stem, which is one reason that I'm not showing you that yet!
lol, Lorax, I'm totally over my head now. So I'm batting 100 instead of a thousand, if you are being generous. Maybe I need to get my Colombian cousin to take a look. She studied something like landscape architecture there. Nah, haven't seen her in a few years. I will be watching this thread for the eventual identification.
Ack! I'm gonna say it's a Piperaceae because of that hint plus the prominent veins. Not on all species in that genus, but one like Piper auritum or hoja santa, yerba sante, et al. P. auritum is in Ecuador among other places and has leaves to 30 cm wide. Plus the most notable veins start at the petiole. (I don't even know how to look up those botanical descriptors.)
Probably I am very far from it but I want to say Gunnera Manicata, I know I know I am wrong but I have to answer this way. I don't know why...
Not Gunnera - new foliage on those, especially juvenile plants, is purplish. This one, as thanrose has suggested, is in the Piperaceae. But it's not Piper auritum. The common name for this one is Maria Panga.
Would that make it Piper peltata ? http://209.85.229.132/search?q=cache:hamPR3TdtCMJ:ip.aaas.org/tekindex.nsf/2a9c4e44835b04ea85256a7200577a64/761c011e622cfd3b85256b03006eab08/Body/M1%3FOpenElement+Piper+Maria+Panga PS "What's round, green, and juvenile?" . . . the obvious answer is modern overweight new recruits in the army ;-)
Yes, it indeed would make it Piper peltatum (incidentally, that is the name it's found under in the Quito National Herbarium and in the Universidad Catolica Herbarium here) - I've never seen it called peltata though. Hmmm.
