We have an unknown plant growing with our cactus. Can you id it?

It looks like some kind of Acacia. Give it more light to get less stringy
growth. You won't be able to tell the species until it blooms. Look up Acacia
to see if it matches. Does it have any thorns?
Iris,
Central NY, Zone 5a, Sunset Zone 40
"When you come to a fork in the road, take it." Yogi Berra