It began growing in one of my houseplants.

It looks like Hops. Did it have flowers? Does it have prickles?

Japanese Hop (Humulopsis scandens)
Hops was my first thought, too.

It looks sort of neat growing up the lattice, but since it can mature to 20' ...

Edited after reading comment to read 35' or more. Definitely not a keeper!

Scroll down and read the comment about this plant by ILPARW.

Definitely not a keeper While it doesn't actually have "prickles" the hairs all over it are very abrasive and if you brush against it the wrong way (FYI every way will be the wrong way ) with bare skin you may have serious skin abrasions (think falling from a speeding motorcycle, without leathers, onto a paved highway and skidding for half a mile ) The 'hops' in the Fall are nice and smell of lemons but unless you can grow this away in a forest, don't bother.

Wow I'm glad I consulted with this forum before touching it. Such a shame because its so pretty.

lfustos said: Wow I'm glad I consulted with this forum before touching it. Such a shame because its so pretty.

If you like it, keep it!
edited to add: It's not built to be a houseplant and require lots of root space (might smother your houseplant that shares the space.) but it is very pretty. Probably not worth the effort to keep inside long-term, though. Be careful where you put it upon disposal. Long ago I planted hops in my herb garden; it's now a hops garden and wants to come up in surrounding lawn, too.

I can't tell you how many times I have innocently brought invasive plants into my yard. I have fought some for many, many years now. Some have simply come on their own from the ether and decided this would be their forever home. Some are viners and others are seed bombs blasting their seeds everywhere.

I can't spend hours trying to rid invaders from my gardens, especially the seed blasters. I have a few of those and can appear a distance from the original plant. My gardens are such that they may grow and I don't notice right away. And that perpetuates the spread/takeover.

Vals_Garden said: Definitely not a keeper While it doesn't actually have "prickles" the hairs all over it are very abrasive and if you brush against it the wrong way (FYI every way will be the wrong way ) with bare skin you may have serious skin abrasions (think falling from a speeding motorcycle, without leathers, onto a paved highway and skidding for half a mile ) The 'hops' in the Fall are nice and smell of lemons but unless you can grow this away in a forest, don't bother.

That would be my definition of prickles and are exactly as you describe. I grew up near a hops farm - short cuts were never without consequence.

Possibly Virginia Creeper and harmless but will grow and grow and grow.

Not Virginia creeper.

tjackintrstarnet said: Possibly Virginia Creeper and harmless but will grow and grow and grow.

I agree with porkpal it is not Parthenocissus quinquefolia ...common name Virginia creeper.
Leaves of this are very different...it has one stalk with 5 leaflets...see pic below