Might I assume that you've followed that stem all the way to the ground to verify that it is actually coming from the orange tree and is not a weed or volunteer of some sort?

that is not citrus.

Looks like Mistletoe.

from Wikipedia:

Lysiana exocarpi, commonly known as harlequin mistletoe, is a species of hemiparasitic shrub, endemic to Australia.

So, you'll probably have to try to cut it out. Follow link for management...

https://www.snelandcare.org.au/linkedfiles/MethodsManageMistletoe.pdf

https://duckduckgo.com/?t=ffcm&q=Lysiana+exocarpi&ia=web

from wiki: is a species of hemiparasitic shrub, endemic to Australia.

well go figure on that ...

since its such.. i bet there are local resources for you:

https://duckduckgo.com/?q=Lysiana+exocarpi+control+in+australia&t=ffcm&ia=web

ken

It is growing from the actual branches of the tree and has some red tips. Seems to be getting worse. ill try and get a better photo today

This is Mistletoe. It is a parasite. Dave is right. It will have to be cut out.... maybe even the branch(s) cut off. But, I have seen that if you keep cutting it off at the branch it will eventually die. We have it here in California too, but I, personally, have never had to deal with it. I do know that the birds eat the berries and p@@p it onto the tree; that's how it gets started.