This vine rather suddenly appeared, clearing the wall of ivy and philodendron that had been there for years. Along with its appearance the philodendron leaves changed from solid glossy green to variegated as shown at the left of the mystery vine leaves. Those vine leaves are palmate, heavily veined, and smooth edged. The large leaf grows
to 5 x 4". No idea where it came from. I sure hope someone can identify it.
I see Syngonium podophyllum leaves with some Ivy in the background. I can't actually see any Philodendron in your photo. I think the Syngonium is starting to take off! Like many climbing aroids the size, shape and colour of the leaves changes quite dramatically as the plant becomes bigger, older and more established.
Thanks. I agree that the leaves on the left are arrowhead plant.( I do not understand why after about 18 years of heart-shaped glossy green leaves the plant suddenly changed to those variegated leaves)
my primary interest however, are the larger leaves on the left: they bear no resemblance whatever to the arrowhead plant leaves. And why did this plant appear to clear the wall over a larger area of both the arrowhead plant and the ivy? And do it so suddenly? What the heck is that vine???
!After a great deal of searching, I finally found a photo of Syngonium podophyllum "Trileaf Wonder that exactly matches my vine.
I still don't understand it taking 18 years to go through all its metamorphoses, nor can I imagine why it cleared even the English ivy from a large area around it on the wall, with both occurring so suddenly! Just another of life's lovely little mysteries, I guess.