I wouldn't be surprised if Peter Paul & Mary knew about the African American children's song "Green Green Rocky Road" as sung by Odetta.

Here's the words to that song as collected by Professor Thomas W. Talley of Fisk University:

GREEN OAK TREE! ROCK'O!

Green oak tree! Rock'o! Green oak tree! Rock'o!
Call dat one you loves, who it may be,
To come an' set gy de side o' me
"Will you hug 'm oce an' kiss im' twice"
"W'y! I wouldn't kiss 'im once fer to save 'is life!"
Green oak tree! Rock'o! Green oak tree! Rock'o!

Source: Thomas W. Talley, "Negro Folk Rhymes, Wise and Otherwise" {Kennikat Press Inc./ Port Washington, N.Y. edition; 1968, p. 81; originially published by Macmillan Press, 1922}

-snip-

This song is listed in the Play Rhymes Section of that book. Unfortunately, there is no accompanying tune. However, as I read this rhyme, I'm singing the tune to "Green Green Rocky Road" that I heard on one of Odetta's earlier records.

In the notes to his now classic book, Dr. Talley indicates that the rhymes he included in "Negro Folk Rhymes" are a samplying of those rhymes he remembered from his childhood and those rhymes that he collected from his [African American] Fisk Univesity students. Talley also writes that many of these songs were quite old when he collected them in the early, mid 1900s.

Given the words of the song, and my reading of how African American children's rhymes were played, my sense is that "Green Oak Tree! Rocky'O" was "originally" performed as a circle game with first one and then two children in the middle. Probably a girl selecting a boy and then when that song was sung again, the girl rejoins the group forming the circle, and the remaining boy then picks another girl, and so on}. My sense is that this game was probably self-initiated by children and played by children who were up to about age 12 years.

Using the words as given above {based on my reading of how African American children's rhymes were played in the early 20th century},
I believe that the group sang the first three lines, probably while holding hands and moving counter clockwise or while standing still and clapping their own hands and stomping their feet to the rhythm of the song. The person in the center probably did not join the group in singing these words. She or he may have clapped & stomped her/his feet to the beat, or just stood still while the group sang their part.

I believe that the first person in the circle sung the first quoted line, and the second person in the group sung the second quoted line.

For what it's worth, I don't believe that either this game song or "Red Light Green Light Rocky Road" as recorded by Peter Paul and Mary is presently known to African American children in the Pittsburgh, Pennsylvania area. I didn't know these songs when I was growing up in the 1950s in Atlantic City, New Jersey.

It's been my experience that few children in the late 20th and early 21st century have sang and played any non-competitive circle games except "Ring Around The Roses" and "Hokey Pokey". Nowadays these two games are rarely played by any girls or boys older than age 5 years. Also, these two games are usually initiated by a teacher, child care worker, mother at a birthday party, or some other adult, and not by the children themselves.

"Stella Ela Ola", "Slap Billy Ola", and other games with similar sounding names are examples of competitive semi-circle or circle children's games with no one in the center of the circle. By "competitive" I mean a chanting game in which the object is to be the last person in the group who remains in the game {the "winner"}.

I've seen these hand slapping while chanting games played in Pittsburgh, Pennsylvania {African American girls and boys, both up to age 12 years}. These games were initiated by an adult [my school teacher daughter] in an after-school setting. However, all the girls and boys knew this game and both were enthusiatic about playing it]. I've also seen text examples of this game with photographs on the Internet being played by non-Black elementary school age girls and boys.

Here's a Mudcat thread on this rhyme:
thread.cfm?threadid=77066#1370542
RE: Kids chant Stella Ola Ola / Stella Ella Ola

Also, visit this page of my website for more examples and performance information of Stella Ella Olaaboand examples of Stella Ola Ola"

http://www.cocojams.com/handclap_rhymes_example_0104.htm