Summer and I were clearing out underneath the mango tree in the back yard a couple weeks ago and notices a bunch of sprouts that we thought could have been palm trees. Without looking at them closer, you might thing they were just thick strands of grass. We watched them grow and decided that we think they may actually be Royal Palms.
It is my understanding the only way that royal palms will grow is after they have been digested and pooped out of a bird. Our theory is that all of the birds that were hanging in our mango tree this summer must have pooped us some royal palm seeds!
At any rate, I transplanted about a dozen of them into small pots; lets see how they do.

They are still in the ground here | Still kinda look like grass

Here some of them are in their happy new home

Do you think they are Royal Palm Saplings?
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My guess is that they are arica palms, still good for landscaping, too. Score ! if they are Royals.
Your place is looking rad.