This stitch is done from right to left…or, better to do from right to left.

My stitch line will follow a spiral shape to show the easy curves this stitch can follow.

petal chain stitch 1       petal chain stitch 2
Fig 1: Bring the needle out through A. Take the needle ‘backwards’ to put it in through B and bring it out through C. The point C lies half way between A and B. Also note that C lies below the stitch A-B.   Fig 2: Now, take the needle in through C again to bring it out from D, but don’t pull out the needle completely. The point D lies straight below C.
petal chain stitch 3   petal chain stitch 4
Fig 3: Loop the thread around the needle from left to right, as illustrated.   Fig 4: Pull out the needle to tighten the loop. Finish up with the first petal chain stitch by putting in the needle just outside the loop, near the point D, as you would in a lazy daisy stitch. Bring out the needle again through E.
petal chain stitch 5   petal chain stitch 6
Fig 5: Now, take the needle in through the earlier stitch point C to bring it out through A. Note that this time, A lies half way through the stitch E-C.   Fig 6: Continue the procedure to make more petal chain stitches.
petal chain stitch 7   Fig 7: A finished pattern with petal chain stitch would look like this.