Jump-rope rhyme

I have tried to find an origin on a lyric I learned as a child. When picking dandelions, we would flick the head of the dandelion off the stem and say "momma had a baby and it's head popped off!".

Anyone know where this came from?

Sounds like a jump-rope rhyme. There are several with a similar line. Here's one (that doesn't make much sense) from "American Children's Folklore: A Book of Rhymes, Games, Jokes, Stories, Secret Languages, Beliefs and Camp Legends for Parents, Grandparents, Teachers, Counselors and All Adults Who Were Once Children" by Simon J. Bronner (August House Inc., Little Rock, Ark., 1988):
Fudge, fudge
Call the judge
Mother's had a newborn baby
It isn't a girl, it isn't a boy
It's just a newborn baby
First floor miss
Second floor miss
Third floor miss.

I've seen in print a variant that made more sense. It went, approximately, "Mamma had a newborn baby / It ain't no girl, it ain't no boy / Just an ordinary baby / Throw it down the elevator . . ." This explains the "nth floor miss" chant. The girl who jumps agilely enough to persist in missing the rope (not tripping on it) through many lines of the chant has symbolically thrown her new sibling down a very tall elevator shaft.